Effects of low temperature on sludge settleability and nutrients removal performance treating d

文献综述题目：生物炭在农业生产上的研究进展生物炭在农业生产上的研究进展摘要：作为重要的土壤改良剂、污染物质吸附剂的生物炭在农业和环境中具有巨大的应用价值和现实意义，因而受到国内外学者们的普遍关注。

生物炭具有多孔性和巨大的表面积，它能够增加土壤的持水量、增加对营养元素的吸附以减少其流失并改善土壤的结构，此外生物炭本身含有丰富的营养元素并能够缓慢释放以供作物吸收，因此生物炭能改善土壤肥力并增加农作物产量。

同时，生物炭巨大的吸附功能可以降低重金属和有机污染物在土壤及污水中的活性，起到降低污染物浓度的作用。

因此生物炭在农业增产和减少污染方面有巨大的潜力。

本文基于生物炭在农业增产和重金属污染治理方面的国内外研究文献，综述了生物炭的基本理化特性及对土壤重金属污染的改良作用，分析了生物炭对土壤肥力及作物增加产量提高品质的影响，阐述了生物炭对土壤重金属污染修复机理,及该领域未来的发展动向，为生物炭的全面研究和应用提供参考。

关键词：生物炭；农业增产；土壤改良；重金属污染治理1 引言生物炭是一种细粒度和多孔的物质，外观类似木炭，是由生物质在缺氧条件下高温热解或燃烧生成。

而在国际生物炭组织(IBI)对生物炭的定义中，进一步强调了其被目的性地施用到农业土壤及其环境效益的需求。

生物炭的生产工艺相对简单, 原材料来源广泛且价格低廉, 使得炭在农业生产上应用成为了可能。

生物炭施入土壤以后, 可以增加土壤的碳汇, 缓解气候危机; 还可以提升土壤肥力, 增加作物产量。

在中国，重金属污染和农业面源污染已经成为国家和科学家们重点关注的环境问题，并且我国的重金属治理形势极其严峻。

同时由于70年代以来，农民过量使用化肥和杀虫剂等造成了Ｎ、Ｐ等营养元素以及有机污染物通过土壤进入水体造成了严重的有机污染以及水体富营养化，鉴于生物炭的多孔性以及较大的表面积，为改善中国的面源污染提供了可靠的途径。

2 生物炭在农业生产上的研究进展2.1 生物炭的概念及其理化性质目前为止，生物炭还没有十分确切的定义。

低温、紫外胁迫对植物的影响的英语1. The effects of low temperature and UV stress on plants have been extensively studied.2. Researchers have investigated the impact of low temperature and UV stress on different plant species.3. This study aims to analyze the responses of plants to low temperature and UV stress.4. The effects of low temperature and UV stress can be detrimental to plant growth and development.5. Understanding the mechanisms underlying the response of plants to low temperature and UV stress is important for crop breeding.6. Low temperature and UV stress can induce significant changes in physiological and biochemical processes in plants.7. Recent studies have shown that low temperature and UV stress can alter the expression of genes involved in plant defense mechanisms.8. The effects of low temperature and UV stress on plants are mediated by various signaling pathways.9. Plant tolerance to low temperature and UV stress can be enhanced through genetic modification.10. The effects of low temperature and UV stress on plants can vary depending on the duration and intensity of exposure.11. Low temperature and UV stress can lead to the accumulation of reactive oxygen species in plants.12. The production of antioxidants is increased in response to low temperature and UV stress in plants.13. Certain plant species have developed specific mechanisms to cope with low temperature and UV stress.14. The effects of low temperature and UV stress on photosynthesis in plants have been extensively studied.15. Plant growth and development can be hindered by low temperature and UV stress.16. The effects of low temperature and UV stress on plant metabolism have been well-documented.17. Low temperature and UV stress can affect the nutritional composition of plants.18. Plants exposed to low temperature and UV stress may exhibit changes in leaf morphology.19. The effects of low temperature and UV stress on plant reproductive processes have been investigated.20. Stress-responsive genes are upregulated in plants subjected to low temperature and UV stress.21. Low temperature and UV stress can lead to alterations in plant hormone signaling pathways.22. Plant defense mechanisms are activated in response to low temperature and UV stress.23. The effects of low temperature and UV stress on plant water relations have been studied.24. Low temperature and UV stress can induce cell membrane damage in plants.25. The impact of low temperature and UV stress on plant yield and quality has been evaluated.26. Strategies for mitigating the effects of low temperature and UV stress on plants are being explored.。

附录一Biogas recovery from microwave heated sludge byanaerobic digestionBiogas generated from sewage sludge, livestock waste, and food waste by anaerobic digestion is a valuable renewable energyresource. However, conventional anaerobic digestion is not an efficient process. A long hydraulic retention time and low biogasrecovery rate hinder the applications of those resources. An effective pretreatment method to destroy sludge microbial cellshas been one of the major concerns regarding improvement of the biogas production. This article focuses on the effects of microwave heating on sludge anaerobic digestion. Volatile suspended solid (VSS) and chemical organic demand solubilization of heated sludge were investigated. Microwave heating was found to be a rapid and efficient process for releasing organic substrates from sludge. The increase of organic dissolution ratio was not obvious when holding time was over 5 min with microwave heating. The effect of the VSS solubilization was primarily dependent on heating temperature. The highest value of VSS dissolving ratio, 36.4%, was obtained at 170°C for 30 min. The COD dissolving ratio was about 25% at 170°C. Total organic carbon of treated sludge liquor was 1.98 and 2.73 g/L at 150°C and 170°C for 5 min, respectively. A biochemical methane potential (BMP) test of excess sludge and a mixture of primary and excess sludge demonstrated an increase in biogas production. The total biogas from microwave treated mixture sludge increased by 12.9% to 20.2% over control after 30 days of digestion. Biogas production was 11.1% to 25.9% higher for excess sludge than for untreated sludge. The VS removal ratios of mixture sludge and excess sludge were 12% and 11% higher, respectively, compared to the untreated sludge.biogas recovery, microwave heating, sludge, anaerobic digestion 1 IntroductionWastewater treatment plants produce large amounts of primary and excess sludge that contains organic bacterial microbes and inorganic mineral components. State EPA reports have indicated that there are approximately 11 million tons of dewatered sludge cakes (about 80% moisture content) generated annually in China. In recent years, treatment and disposal of sludge have become a serious problem in many cities.Anaerobic digestion is a common process for sludge treatment. Compared with other processes, its advantages are lower energy requirement, better stabilized product, and generation of usable gas. However, the biological gel structure properties of sludge result in difficulties in anaerobic digestion. Pavlostathisetal.andVavilin et al.found that the bacterial cell wall restrained the biodegradability of sludge. An effective pretreatment method to destroy microbial cells has therefore been one of the major concerns in the sludge pretreatment process. Wang et al. Baier et al. Lin et al.and Tanaka et al.separately carried out sludge pretreatment research to improve biogasproduction and included ultrasonic, mechanical,alkaline, and thermal-chemical treatments for degradation of microbes. Heat treatment was a harsh process that disrupted bacterial cell wall, and released and hydrolyzed high molecular weight materials. Brook found that the hydrolysis of organics was a dominant characteristic that distinguished heat treatment from other methods. Industrial application has proven the effectiveness of heat treatment; for example, Kepp et al. stated that when sludge was heated with a Cambi process at 170°C, the volatile solids (VS) removal ratio of the treated sludge increasedfrom about 40% to approximately 60%. Using the advantages of the improved settling performance of heated sludge,Wang et bined heat treatment with an anaerobic sequenced batch reactor to increase the VS removal ratio to 60% with a lower hydraulic retention time (10 days).However, conventional heat treatment is time-consuming .For the purpose of heating sludge, microwave irradiation might serve as an alternative and much more rapid method .In recent years, the use of microwave as a novel technique to treat sludge has attracted much interest.A uniform microwave field generates energy through the realignment of dipoles with oscillating electric fields to generate heat both internally and at the surface of the treated material. Sludge is a multiphase medium containing water,mineral and organic substances, proteins, and cells of microorganisms.Due to its high water content, sewage sludge can absorb significant amounts of microwave energy.Zlotorzynski analyzed the application of microwave irradiation to analytical and environmental chemistry.Eskicioglu et ed sludge heated by microwave to 96°C in a batch anaerobic digestion test and found a 17% biogas increase over untreated sludge. Compared to conventional heat treatment, microwave treatment resulted in more soluble proteins and volatile fatty acids but a lower sugar content of the sludge. Park etal.reported that microwave treated sludge could produce 79% higher methane production than untreated sludge. Wojciechowska used microwave to condition sludge and found that after 180 s of microwave heating, the specific resistance to filtration (SRF) of mixed sludge (primary and secondary sludge)and anaerobic digested sludge decreased by 73% and 84%,respectively. Liao et al.reported that organic hydrolysis,induced by combing microwave with hydrogen peroxide and acid, could be used to recover sludge nutrients.It is evident that the effectiveness of microwave treatment has been recognized by many researchers. However,the exact nature of the sterilization effect, as well as whether this is due solely to thermal effects or to non- thermal effects, has continued to be a matter of controversy. In most conventional heat treatments, sludge is heated at a mild temperature using an open vessel. The higher temperature and pressure that are generated by microwave treatment of sludge in terms of overall biodegradability were investigated in the present paper.2 Materials and methods2.1 Sludge samplingSludge was sampled from three local municipal wastewater treatment plants (the Gaobeidian, Qinghe, and Beixiaohe wastewater treatment plants) in Beijing. These three wastewater works primarily treat municipal sewage. Table 1 presents the characteristics of the sludge. The mixturesludge (MS) was mixed by combining primary and excess sludge sampled from the gravity thickening tank in the Gaobeidian and Beixiaohe plants. Excess sludge (ES) collected from Qinghe plant was thickened in laboratory to a suspended solid (SS) content of 2.8%. After sampling, sludge wasscreened through a 3.2 mm×3.2 mm mesh sieve to remove large particles. The screened sludge was then stored in a refrigerator at 4°C until further testing.MS from Gaobeidian plant was used for the investigation of organics solubilization of sludge with microwave heating.Microwave treated MS from Beixiaohe plant and ES from Qinghe plant was used for evaluation of biodegradation by abiochemical methane potential (BMP) test. Table 1 shows the SS, VS, total COD, and pH.2.2 Microwave heating procedureA commercial domestic microwave oven (2450 MHz, 1000W, MSD6, Shanghai Sineo Co., Ltd) and PTFE vessels were used for microwave irradiation. This frequency of microwave energy has been widely used in scientific research.Sludge microwave heating was performed as batch tests using 30 mL of sludge in a 70 mL PTFE vessel. All test samples were subject to microwave heating at temperatures of 80, 120, 150 and 170°C. The microwave heating holding times were 1, 5, 10, 20 and 30 min. Sludge temperature and pressure were measured and controlled by the microwave oven.2.3 Biochemical methane potential (BMP) testA biochemical methane potential test was used to evaluate biogas recovery from sludge after microwave pretreatment.A 60 mL sample of microwave-heated sludge, seeded with 150 mL of anaerobic digestion sludge, was fed into a 250mL serum bottle. The seed sludge was collected from an anaerobic digestion tank at the Gaobeidian plant. In this plant, gravity thickened sludge was digested at 35°C with 30 days of HRT. A separate 60 mL sample of untreated sludge was used as a control sample. Each test was performed with parallel samples. The BMP tests were performed in a water bath at 35°C. The cumulative gas production was measured using a water displacement method. The serum bottles were shaken every 12 h to allow for sufficient blending. The methane content in the biogas was measured by a gas chromatograph equipped with a thermal conductivity detector.2.4 Analysis methodsThe total COD (TCOD) was determined by the potassium dichromate/ferrous ammoniumsulfate method. Sludge particles were kept uniformly suspended by a magnetic stirrerwhile sampling. The supernatants were separated from sludge by centrifuging (LG10-2.4A) at 2775 g for 10 min and were used for soluble COD (SCOD) determination. The total solid (TS) and SS were measured by drying sludge slurry at 105°C for 24 h; VS and VSS were tested by burning the dried sludge at 600°C for 2 h. For SS and subsequent VSS analysis, sludge was centrifuged prior to heating,to remove soluble solids as described in SCOD determination.TOC of sludge liquid was measured by Shimadzu’s TOC-5000.3 Results and discussion3.1 Temperature increases by microwave heatingCompared with conventional sludge heating, microwave heating is much more rapid. When materials are heated by high frequency electromagnetic waves, the heating effect arises from the interaction of the electric field component of the wave with charged particles in the material. Power absorbed by materials becomes higher as the penetration depth decreases. As a result of the complicated composition of sludge, the absorption of microwave energy will be influenced by organics (such as proteins, lipids, and carbohydrates)and solid concentration, as well as by the heatingLoad. Hong et al.reported that water absorbed microwave energy was in an exponential relationship with the heating load, and that the absorption efficiency could reach 80%.Figure 1 presents the heating and cooling curves in sludge microwave treatment at 120, 150 and 170°C for 5 min. Under microwave irradiation, sludge temperature increased rapidly, and the heating ratios were similar for the different temperatures. The microwave irradiation times to 120, 150 and 170°C were 4, 7 and 7.5 min, respectively. When the sludge was heated to pre-set temperature, sludge was kept at a stable temperature for 5 min. This time was called heating time. When the heating finished, the reactor filled with sludge was transferred from microwave oven into a cool water bath. The decline parts of the curves in Figure 1 representthe cooling of sludge.3.2 Organic sludge dissolving trendsThe conventional heat treatment performed by Wang et al. demonstrated that inorganic components dissolved at a lower dissolution ratio, and that the main part of the solid dissolution was due to VSS hydrolysis. Brooks presented a summary of the solid matter in the sludge and followed their pathways of dissolution and hydrolysis. First of all, the floc of microorganism was found to disperse anddisintegrate. The intracellular material was released, dissolved,and hydrolyzed as follows: lipids were hydrolyzed to palmitic acid, stearic acid, and oleic acid; proteins were degraded to a series of saturated and unsaturated acids,ammonia, and some carbon dioxide, while carbohydrates were broken down to polysaccharides of smaller molecular weight and, possibly, even to simple sugars. Therefore,volatile suspended solid (VSS) were generally taken as a principal parameter of organic hydrolysis.VSS dissolution depicted the tendency of sludge to become an inorganic product. Figure 2 presents changes in sludge VSS dissolution under different conditions. Holding times from 1 to 30 min were used at the temperatures of 80,120, 150 and 170°C. The VSS dissolution ratios substantially increased with rising temperature and prolonged holding time. However, the increases in dissolution were not obvious when the holding time was beyond 5 min. The effect onthe VSS dissolution was mainly dependent on the temperature. The highest value of VSS dissolution ratio,36.4%, was obtained for a treatment at 170°C for 30 min.The COD dissolution was the portion of TCOD in the sludge solid that was hydrolyzed into the liquor during the microwave irradiation. COD dissolution showed organicmatter dissolution. Microwave irradiation caused significant increases in COD concentrations. This corresponded to cell damage as a mechanism of microwave thermal treatment.The highest COD dissolution was 25.8% at 170°C for 10min (seen in Figure 3).The tendency toward COD dissolution, as affected by microwave heating temperature and time, was consistent with the VSS dissolution. Accordingly, SCOD concentration of treated sludge also showed a similar trend with temperature and holding time. As shown in Figure 4, at 170°C,the SCOD of sludge was about 10 g/L. As also shown in Figure 5, the mean value of TOC concentration increased with the microwave irradiation temperature and time, and reached the highest value, 3.4 g/L, with a treatment of 170°C for 30 min. The microwave thermal pretreatment caused a substantial dissolution and hydrolysis of organics.This suggests that microwave irradiation is capable of additionally decomposing complex chemical compounds and hydrolyzing them into simple compounds that can then be easily decomposed by bioprocesses. This effect can be used to enhance the sludge digestion process, as shown in the present results.3.3 Biogas recovery from microwave treated sludgePino-Jelcic et al. compared microwave treatment with conventional heat treatment at 60–65°C,and found that the sludge VS removal ratio of microwave-treated sludge by anaerobic digestion was 53.9%, while the ratio was 51.3%for conventional thermal treated sludge with anaerobic digestion.Microwave treatment was helpful in disrupting the cell membranes of sludge bacteria, destroying more E. Coli and releasing more intracellular materials. Heo et al. used a BMP test to evaluate the anaerobic digestibility of alkaline-treated sludge. A hydrolysis test showed that the VSS dissolution did not increase significantly with the prolongation of holding time beyond 5 min and that VSS dissolution was low at 80°C.In the present study, microwave heated sludge used for the BMP test was heated to temperatures of 120, 150 and 170°C for 5 and 10 min. Compared to ES, primary sludge and amixture of primary and ES could be readily digested.In order to analyze the microwave effect on different types of sludge, both MS from Beixiaohe and ES from Qinghe were tested. Cumulative biogas production of MS is shown in Figure 6. After microwave treatment, total biogas production increased by 12.9% to 20.2% over the control after 30 days of digestion. Figure 7 presents the cumulative total biogas production of ES. This production was 11.1% to 25.9% higher than untreated sludge. The highest biogas production was obtained from the sludge treated by microwave at 170°C for 10 min. Microwave heating as a pretreatment method for MS and ES therefore appeared to be effective in obtaining higher biogas production.Both batches used for BMP gas production showed a fast rate for the first 10 days, then the gas production ratio decreased and stabilized. As seen in Figures 6 and 7, the amount of biogas generated for MS from Beixiaohe plant was higher than that from ES. This was most likely due to differences in organic load, as MS contains more organic content than ES. However, microwave pretreatment improved the sludge anaerobic digestibility for both MS and ES. The microwave treatment temperature was more sensitive for MS than for ES.VS removal ratio in anaerobic digestion was another parameter that affected sludge biodegradability. Figures 8 and 9 present the VS removal ratios of the microwave treated MS from Beixiaohe plant and ES from Qinghe plant, respectively.The VS removal ratio of MS microwave treated at 170°C for 5 min was 12% higher than that for the untreated sludge. For ES, the VS removal ratio increased by 11%compared to untreated sludge.4 ConclusionsMicrowave heating using a domestic microwave oven with a frequency of 2450 MHz wasable to accomplish a rapid temperature increase in sludge. Therefore, as an alternative method, microwave treatment should also prove effective on an industrial scale. VSS dissolution approached values comparable to those by conventional heat treatment. The COD dissolution and the changes of TOC also indicated the same degree of organic component hydrolysis. At 170°C,the VSS dissolution ratio of treated sludge reached 36.4% and COD dissolution ratio was about 25%. Under this typical hydrolysis parameter, microwave irradiation could shorten holding time to 5 min, compared to conventional processes that require more than 30 min. This provided the possibility of shortening system sludge retention time,therefore saving energy and construction costs for industrial applications.Compared with microwave conditioning, higher temperature with a pressure vessel could also bring notable effects with relatively mild temperatures. Microwave irradiation was shown to be effective at improving sludge biodegradability for both MS and ES, allowing a greater recovery of biogas. The BMP test showed a significant improvement in biogas production and in the VS removal ratio. The results of this study indicate that higher biogas production is possible at temperatures no higher than 170°C.利用厌氧消化从微波加热的污泥中获取沼气通过厌氧消化的污水污泥，禽畜废物，食品废物产生沼气是一种宝贵的可再生能源资源。

The Effect of Temperature on ProteinConformationProteins are essential components of living organisms and are responsible for carrying out various cellular functions. They are composed of long chains of amino acids that are folded into intricate 3-dimensional structures. The specific shape of a protein, or its conformation, plays a critical role in its function. Temperature is one of the key factors that can influence protein conformation. In this article, we will explore the effect of temperature on protein conformation and how it impacts their function.Temperature-induced protein denaturationProtein denaturation is a process in which the protein loses its native conformation and unfolds into a linear or random coil structure. This process can be triggered by several factors, including pH, salts, mechanical stress, and temperature. Among these, temperature is the most commonly studied factor that can induce protein denaturation.When proteins are exposed to high temperatures, the thermal energy causes the bonds that hold the protein structure together to break. Hydrogen bonds, which are weaker than covalent bonds, are the first to be broken. As the temperature continues to rise, the more significant covalent bonds that hold the protein together begin to break, further destabilizing the structure. Ultimately, the protein loses its native conformation, and its function is impaired.The effect of temperature on protein stabilityThe stability of a protein refers to its ability to maintain its native conformation in the face of various environmental conditions, including temperature. The stability of a protein is influenced by several factors, including the amino acid sequence, solvent conditions, and the presence of ligands or cofactors. Temperature can disrupt the stability of a protein by altering its structure and causing it to denature.Proteins have a range of thermal stability that depends on their amino acid sequence and their specific structure. Generally, proteins that are stable at higher temperatures have a higher content of hydrophobic amino acids, which can help to stabilize the structure through hydrophobic interactions. In contrast, proteins that are stable at lower temperatures tend to have more polar amino acids and a lower content of hydrophobic amino acids.The temperature at which a protein denatures is known as its melting temperature or Tm. The Tm of a protein is influenced by its intrinsic stability as well as the specific conditions under which it is studied. For example, the pH, salt concentration, and presence of other molecules can all affect the Tm of a protein.The effect of temperature on protein functionThe specific conformation of a protein plays a critical role in its function. Therefore, changes in protein conformation due to temperature can have a significant impact on their function. The effect of temperature on protein function can vary depending on the specific protein and the conditions under which it is studied.Some proteins are more sensitive to changes in temperature than others. For example, enzymes, which catalyze chemical reactions in the cell, have a specific optimal temperature range at which they function best. Outside of this range, the reaction rate can slow down or even stop altogether due to changes in protein conformation.Other proteins, such as transporters and receptors, are also sensitive to changes in temperature. Changes in protein conformation due to temperature can affect the ability of these proteins to bind to their ligands and carry out their function.ConclusionIn conclusion, temperature has a significant impact on protein conformation. High temperatures can cause proteins to denature, while changes in temperature can alter their stability and affect their function. Understanding the effect of temperature on protein conformation and function is essential for designing experiments and developing new drugs and therapies that target specific proteins.。

UASB反应器降解偶氮和蒽醌染料废水的特性吕仪婧，邓志毅*，肖利平（湘潭大学环境科学与工程系，湖南湘潭411105）摘要：采用UASB反应器，在中温（35±1℃）条件下，分别处理了偶氮类（活性艳红X-3B和KD-8B）和蒽醌类（活性艳蓝K-GR）模拟染料废水，对比研究了反应器运行条件，探讨了回流比、水力停留时间和染料种类等因素对染料脱色率的影响。

结果表明：采用维持水力停留时间（hydrodynamic retention time, HRT）为24 h，逐步提高进水染料浓度的方式，在约25d内成功启动反应器。

当偶氮类（活性艳红X-3B）和蒽醌类（活性艳兰KG-R）染料的进水浓度为100 mg/L，回流比为2~2.5倍时，系统的COD 去除率和脱色率均可达到90%以上；过高的回流比不利于染料的脱色；染料种类的变化对其脱色影响不大，但HRT的缩短对染料脱色有较大的影响。

紫外-可见光谱分析显示，偶氮染料脱色是通过偶氮键的断裂，而蒽醌染料脱色则是通过蒽醌共轭结构的破坏来实现的。

关键词：UASB；厌氧；染料废水；偶氮染料；蒽醌染料Degradation Performance of Azo and Anthraquinone Dye1Wastewater Treated by UASB ReactorsLV Yijing，DENG Zhiyi*，XIAO Liping(Department of Environmental Science and Engineering，Xiangtan University，Xiangtan 411105，Hu’nan，China)Abstract: The dyeing wastewaters, which is composed of azo dye – X-3B(C.I.Reactive Red2，referred to as X-3B or RR2), KD-8B(C.I.Reactive Red20，referred to as KD-8B or RR20) and anthraquinone – KG-R （C.I.Reactive Blue19，referred to as K-GR or RB19）respectively, were treated by two same size Upflow Anaerobic Sludge Bed (UASB) reactors under mesophilic condition (35±1℃). During this experiment, the effect of effluent recycle rate, hydraulic retention time (HRT) and the type of dyes were all investigated. The results indicated that two reactors were all successfully started up in about 25 d through the operation fashion of improving the influent dye concentration step by step and maintaining HRT of 24h. The COD removal and decoloration rate could obtain above 90% in two reactors with the influent X-3B and K-GR concentration of 100 mg/L and recycle rate of 2~2.5 times. High recycle rate is not benefit for improving decoloration rate. The change of dye types had little effects on its decoloration rate, but the decrease of HRT had large effects on the decoloration rate. Based on the results of UV-Vis spectra analysis, the decoloration of azo and anthraquinone dye was achieved by the breakage of azo and anthraquinone bond respectively.基金项目：国家重大专项东江项目子课题四（2009ZX07211-005-04）,湘潭大学博士启动基金(08QDZ31)。

温度对半导体影响的书英文回答：The effect of temperature on semiconductors is acrucial aspect to consider in the field of electronics. As temperature changes, it can have both positive and negative impacts on the performance and reliability of semiconductor devices.One of the main effects of temperature on semiconductors is the change in electrical conductivity. Generally, as temperature increases, the conductivity of a semiconductor also increases. This is due to the increased thermal energy, which allows more charge carriers to move freely within the material. As a result, the resistance of the semiconductor decreases, and it becomes more conductive.However, this positive effect of temperature on conductivity can also have negative consequences. For instance, if the temperature rises too high, it can lead tothermal runaway, where the increased conductivity causes excessive heating and further increases the temperature. This can ultimately result in the device failing or even burning out.Another important effect of temperature on semiconductors is the impact on bandgap energy. The bandgap energy is the energy difference between the valence band and the conduction band in a semiconductor. At higher temperatures, the bandgap energy decreases, which meansthat the semiconductor becomes more conductive and allows more charge carriers to move across the bandgap. This can affect the performance of devices such as diodes and transistors, as it can lead to increased leakage currents and reduced efficiency.Furthermore, temperature can also affect the mobility of charge carriers in semiconductors. Mobility refers to the ease with which charge carriers can move through the material. At higher temperatures, the mobility of both electrons and holes in a semiconductor generally increases. This can lead to improved device performance, as the chargecarriers can move more freely and quickly. However, at extremely high temperatures, the mobility can besignificantly reduced due to scattering effects, which can negatively impact device performance.In addition to these electrical effects, temperaturecan also affect the mechanical properties of semiconductors. For example, as the temperature changes, the coefficient of thermal expansion of the semiconductor material can cause stress and strain in the device. This can lead to mechanical failure or even cracking of the semiconductor.中文回答：温度对半导体的影响是电子领域中需要考虑的一个关键因素。

2024年高一英语气候科学研究进展练习题40题1.Climate change is mainly caused by the increase in _____.A.greenhouse gasesB.pollutionC.wasteD.noise答案：A。

“greenhouse gases”是温室气体，气候变化主要是由温室气体增加引起的。

“pollution”污染，范围太广，不一定直接导致气候变化。

“waste”废物，和气候变化关系不大。

“noise”噪音，与气候变化毫无关系。

2.Scientists are studying ways to reduce _____.A.climate changeB.global warmingC.pollution levelsD.carbon emissions答案：D。

“carbon emissions”是碳排放，科学家正在研究减少碳排放的方法。

“climate change”气候变化是结果不是要减少的对象。

“global warming”全球变暖也是结果。

“pollution levels”污染水平，比较宽泛，不如减少碳排放具体针对气候变化。

3.The melting of glaciers is a result of _____.A.rising temperaturesB.polluted airC.waste disposalD.noise pollution答案：A。

冰川融化是温度上升的结果。

“polluted air”污染的空气，不是冰川融化的直接原因。

“waste disposal”废物处理，与冰川融化无关。

“noise pollution”噪音污染，和冰川融化毫无关系。

4.One way to combat climate change is to increase the use of _____.A.fossil fuelsB.renewable energyC.nuclear powerD.coal答案：B。

现在城市化步伐愈来愈快，城市化的发展必然带来污水量不断增多，污水处理厂产生的污泥处理问题渐渐得到了重视。

目前，对污泥处理解决依然存在问题，污泥处理问题愈加严重。

将污泥进行简单干燥处理或直接利用，既没有对污泥中的重金属进行固化、钝化处理，也没有对其中的微生物进行消杀，这些污染物通过大气、水、食物链等多种途径造成二次污染，危及人类健康。

《“十四五”城镇污水处理及资源化利用发展规划》（发改环资〔2021〕827号）要求城市污泥无害化处理处置率达到90%以上，破解污泥处置难点，实现污泥减量化、无害化、资源化处置。

现有污泥处置能力不能满足需求。

为了加快压减污泥填埋规模，积极推进污泥资源化利用，“十四五”期间，要求新增污泥（含水率80%的湿污泥）无害化处置设施规模不少于2万t/d ，必须要求污泥无害化处置途径。

鼓励采用热水解、厌氧消化、好氧发酵、干化、碳化等方式进行无害化处理，提升城市污泥协同综合处置能力。

把污泥的减量化、无害化处理工艺与技术融合到烧结砖的生产工艺中，把经过无害化处置的污泥生产烧结砖。

利用烧结砖瓦企业的余热实现污泥脱水减量化、无害化、资源化及污泥的进一步碳化，具有污泥处置量大、处置过程无害化、性能优异的优势。

处置后的污泥资源化利用是砖瓦行业向固废资源化利用方向转型升级的途径之一和发展方向，可用于生产普通烧结砖、烧结保温砌块、清水砖等墙体材料。

同时，污泥的资源化利用，为城市固体废弃物综合利用找到一个好途径，参与城市生态文明圈的建设，为城市生态建设做出贡献。

污泥主要是城市污水处理和工业废水处理产生的固体废物，分为城市污泥和工业污泥两大类。

前者属于一般固体废物，是烧结砖行业主要资源化利用的对象，而后者则需要具体对待。

城市污泥是污水处理厂净化污水以后产生的固体废物，是沉淀污泥和生物处理污泥的混合物，水分高达80%左右。

污泥里面含有病原体、重金属、微生物等有害物质，要将污泥中的水分脱去是一件非常困难的事情。

生物质碳的性质及环境应用1 生物质炭的性质生物质炭指在缺氧或限氧条件下对生物质进行高温热解处理后的残余固态物质，同时伴随着可燃气体和生物油的产生。

生物质炭的物化性质（如元素的含量、比表面积、孔隙结构、总孔容和表面官能团等）和产率与所用原料和制备条件（如温度、停留时间和压力等）紧密相关。

总的来说，生物质炭是一种含有多环芳烃等多种表面官能团的多碳物质，具有孔隙结构发达和高度的化学/生物稳定性分子结构的特点。

通常认为，生物炭属于黑炭范畴的一种，根据生物质材料的来源，生物炭可以分为木炭、竹炭、秸秆炭、稻壳炭等[1]。

同时，生物质炭含有的多种化学官能团使其能显示出亲水、疏水、酸性等多种性质[2]。

生物质炭的环境功能主要决定于其理化性质。

制备生物质炭的材料和制备条件如温度、氧气含量和时间对生物质炭的性质有比较大的影响[3]。

因此，由于制备生物质炭的原料不同，制备条件各有差异，获得的生物质炭的性质存在很大差异。

例如，畜禽粪制备的生物质炭养分含量高于木屑制备的生物质炭的。

高温条件下制备的生物质炭(700 ℃)比低温下制备的生物质炭(400 ℃)有更高的孔隙度，吸附能力也较强。

Mahinpey等[4]采用小麦秸秆探讨了热解压力、温度和气流速率对生物质炭产率和性质的影响，发现生物油的产率随着压力的增高而增大，生物质炭相比于原秸秆具有更低的H:C和O:C比。

Hossain等[5]研究了温度对活性污泥生物质炭的产率和性质的影响，指出生物质炭产率和氮含量随着热解温度的升高而降低，而微量元素含量却随温度上升而上升。

Ozcimen等[6]使用杏核、榛壳、葡萄籽和栗壳几种不同的生物质原料进行生物质炭的制备，指出生物质炭是一种含碳量高、热值高和相对无污染的潜在固体生物能源。

2 生物质炭的环境应用研究发现，生物质炭具有改良土壤，提升土壤肥力，增加土壤中碳汇，减少温室气体排放等作用。

同时，生物质炭的孔隙结构发达，表面官能团丰富，生物稳定性高等特点，使其可以作为一种吸附剂进行使用[7]。

污泥低温干化机网带对除湿效能影响的实验测试与分析*刘道广（上海同臣环保有限公司，上海200092）【摘要】研究了污泥低温干化机的网带层数与网带铺泥厚度对回风温度、湿度、出水产能及压降的影响，并以此评估出适用于污泥低温干化机网带干化污泥颗粒的最佳工况。

结果表明，在4层网带中（4层a 工况），污泥颗粒在0.60m/s 的网带送风速度下干燥后的出水产能最小为20.7kg/h，相比于2层网带中污泥颗粒在0.90m/s 下干燥后最大的出水产能（19.7kg/h ）仍高5.1%，可知4层网带污泥颗粒干燥后的出水产能更多，干燥效果更好。

在网带层数的影响下，4层网带中的出水产能相较于2层网带最大可提升60.1%。

在网带铺泥厚度的影响下，4层网带中的出水产能最大可提升11.3%，2层网带中最大出水产能相较于最小出水产能提升了44.0%。

网带送风速度为0.90m/s 时的出水产能相较于网带送风速度为0.60m/s 时的出水产能最大可提升36.0%。

研究发现网带层数对污泥低温干化机的除湿效能影响最为重要。

【关键词】污泥干化；除湿效能；网带层数；网带厚度；网带送风速度中图分类号：X703文献标识码：A文章编号：1005-8206（2024）02-0069-06DOI ：10.19841/ki.hjwsgc.2024.02.010Experimental Test and Analysis of the Influence of Sludge Low-temperature Dryer Mesh Belt on Dehumidification Efficiency LIU Daoguang（Shanghai Tongchen Environmental Protection Co.Ltd.，Shanghai200092）【Abstract 】The effects of the number of mesh belt layers and the thickness of the mesh belt sludge spreading on thereturn air temperature，humidity，aqueous output capacity，and pressure drop were investigated.The optimum working conditions applicable to the mesh belt of a sludge low-temperature dryer for sludge particles were evaluated.The result indicated that in four-layer mesh （a condition of four-layer a ），the sludge particles in the 0.60m/s mesh belt air velocity had the lowest water yield of 20.7kg/h after pared with the maximum water yield（19.7kg/h ）of the sludge particles in the two-layer mesh belt after drying ，it was still 5.1%higher.It could be shown that the water yield after drying of the four-layer mesh belt sludge particles was more，and the drying effect was superior.Under the influence of the number of layers of mesh belt，the water yield of the four-layer mesh belt could be improved by 60.1%when compared to the two-layer mesh belt.Under the impact of the thickness of the mesh belt sludge spreading，the maximum output capacity of the four-layer mesh belt could be increased by 11.3%.And the maximum output capacity of the two-layer mesh belt could be increased by 44.0%when compared to the minimum output capacity.The maximum increase of the water yield under 0.90m/s mesh belt air velocity could be raised by 36.0%when compared to 0.60m/s.The study founded that the number of mesh belt layers had the greatest influence on the dehumidification efficiency of sludge low-temperature dryer.【Key words 】sludge drying；dehumidification efficiency；number of mesh belt layers；mesh belt thickness；mesh beltair velocity*基金项目：上海市科技创新行动计划项目（21DZ1210005）收稿日期：2023-12-18；录用日期：2024-03-12文章栏目：热化学处理与烟气污染控制文章类型：研究论文刘道广.污泥低温干化机网带对除湿效能影响的实验测试与分析［J ］.环境卫生工程，2024，32（2）：69-74.LIU D G.Experimental test and analysis of the influence of sludge low-temperature dryer mesh belt on dehumidification efficiency ［J ］.EnvironmentalSanitation Engineering ，2024，32（2）：69-74.0引言针对污泥的处理处置技术主要有卫生填埋、干化焚烧、厌氧消化、土地利用和好氧堆肥技术［1］。

In fluence of pyrolysis temperature on production and nutrient properties of wastewater sludge biocharMustafa K.Hossain a ,*,Vladimir Strezov a ,K.Yin Chan b ,Artur Ziolkowski a ,Peter F.Nelson aa Graduate School of the Environment,Faculty of Science,Macquarie University,NSW 2109,Australia bNSW Industry and Investment,Locked Bag 4,Richmond,NSW 2753,Australiaa r t i c l e i n f oArticle history:Received 21December 2009Received in revised form 6August 2010Accepted 6September 2010Available online 27September 2010Keywords:Wastewater sludge Biochar Pyrolysis Nutrientsa b s t r a c tThe important challenge for effective management of wastewater sludge materials in an environmentally and economically acceptable way can be addressed through pyrolytic conversion of the sludge to biochar and agricultural applications of the biochar.The aim of this work is to investigate the in fluence of pyrolysis temperature on production of wastewater sludge biochar and evaluate the properties required for agronomic applications.Wastewater sludge collected from an urban wastewater treatment plant was pyrolysed in a laboratory scale reactor.It was found that by increasing the pyrolysis temperature (over the range from 300 C to 700 C)the yield of biochar decreased.Biochar produced at low temperature was acidic whereas at high temperature it was alkaline in nature.The concentration of nitrogen was found to decrease while micronutrients increased with increasing temperature.Concentrations of trace metals present in wastewater sludge varied with temperature and were found to primarily enriched in the biochar.Ó2010Elsevier Ltd.All rights reserved.1.IntroductionWastewater sludge is a byproduct of the wastewater treatment process and is composed of organic compounds,macro and micronutrients,trace elements,micro organisms and micro pollutants.The high concentration of phosphorus and nitrogen in wastewater sludge as well as other micro and macro nutrients,has been the primary reason for the application of wastewater sludge for cultivation of crops (Sumner,2000;Singh and Agrawal,2008).Generally,nitrogen is the land limiting constituent when municipal wastewater sludge and animal wastes are applied to the soil (Overcash et al.,2005).The total nitrogen in wastewater sludge is variable and may range from <0.1to 18%with a median of 3.3%and the level of mineral nitrogen may reach up to 6.7%(Sommers,1977).The composition of the sludge varies remarkably over time from a given treatment facility because most of the nitrogen in sludge is in organic form (Magdoff and Chromec,1977;Sommers,1977).Mineralisation of organic N is dependent on type of organic material,rate of application,soil type,water content of the soil and soil temperature (Clark and Gilmour,1983;Parker and Sommers,1983;Barbarika et al.,1985).Beside the nitrogen content,wastewater sludge also is a source of phosphorus.The concentra-tion of phosphorus in the sludge is variable and may vary from less than 0.1%to 14%on dry weight basis depending on the nature of the raw sludge and the treatment process (Sommers,1977).McLaughlin (1984)reported variations in the forms of phosphorus in sludge depending on the composition of the raw sludge and type of the wastewater treatment process.Phosphorus in the sludge is mostly present in an inorganic form and its bioavailability depends on the compounds used for sludge stabilisation (Joao et al.,1997).The plant available phosphorus in sludge varies between 25and 40%compared to inorganic phosphorus.McLaughlin and Champion (1987)showed that phosphorus in the sludge acts as a slow release P fertiliser in the sesquioxic P de ficient soils.On the other hand,phosphorus accumulation in soils through application of sludge could have adverse environmental impacts on surface and ground water through leaching (Sumner,2000).Sewage sludge is also enriched with metals,such as Cr,Cd,Cu,Ni,Se and Zn,pathogens and low concentration antibiotics,which are of the major concern limiting its potential use as a fertiliser (McBride,1995;Overcash et al.,2005;He et al.,2010).Conversion of organic materials to biochar through pyrolysis supports an alternative way to manage a range of wastes (Hospido et al.,2005;Bridle and Pritchard,2004;Strezov and Evans,2009).Pyrolysis of wastewater sludge can potentially be a method of choice for its management,particularly compared to the current*Corresponding author.Tel.:þ61298507978;fax:þ61298507972.E-mail address:kamal.hossain@.au (M.K.Hossain).Contents lists available at ScienceDirectJournal of Environmental Managementjournal homepage:www.elsev /locate/jenvman0301-4797/$e see front matter Ó2010Elsevier Ltd.All rights reserved.doi:10.1016/j.jenvman.2010.09.008Journal of Environmental Management 92(2011)223e 228methods of landfilling and direct agricultural utilisation(Hwang et al.,2007)as this process reduces the volume of the solid residue,eliminates pathogens and organic compounds of concern present in the sludge(Caballero et al.,1997;Koch and Kaminsky, 1993).Biochars are carbon rich materials that contain a range of plant nutrients and can be valuable as soil amendments.The chemical composition of the biochar depends on the source of feedstock and pyrolysis conditions(Chan and Xu,2009).The concentration of nitrogen and/or phosphorus in the sludge may be reduced by the pyrolysis conditions through the evolution of higher molecular weight volatiles,while the concentration of metals present in the biochar is expected to increase.Biochar yield also varies signifi-cantly depending on the production procedure,processing and source properties(Lehmann et al.,2006).Numerous studies have been conducted on pyrolysis of biomass as a potential energy source(Chan and Xu,2009;Tsai et al.,2006;Horne and Williams, 1996).Less attention has been given to the effect of pyrolysis on biochar properties especially on the total nutrient concentration and their availability(Chan and Xu,2009).The aim of this work is to investigate the influence of pyrolysis temperature on the production and nutrient properties of waste-water sludge biochar.2.Experimental2.1.Wastewater sludge materialsDigested wastewater sludge sample was collected from an urban wastewater treatment plant in the Sydney region.The sampling was conducted three times at a regular interval from the same batch to make a composite sample.The wastewater sludge sample used in this work wasfirst dried at room temperature and then separated from other physical impurities,such as small frac-tion of leafs and plastic bags.The sample was then dried at36 C for two days and stored in air tied plastic bags until pyrolysed.The sample was pyrolysed under controlled pyrolysis conditions to ensure uniform heating and treatment.Biochar production was carried out using afixed bed horizontal tubular reactor with dimensions of3.5cm in diameter and16cm in length,set at a heating rate of10 C minÀ1at four peak temperatures of300 C, 400 C,500 C and700 C.Nitrogen gas set at50L/min wasflown through the reactor and the offgas was passed through a water cooling chamber which condensed the heavy tars.Biochar production at each temperature was replicated four times.The quantity of feedstock used for the pyrolysis was in the range of 264e273g.The percentage of biochar yield at various temperatures was calculated from the mass of the original sludge and the weight of the produced biochar after completion of the pyrolysis.2.2.Chemical analysisThe composition of the wastewater sludge sample used in this study was assessed on air dried basis using proximate and ultimate analysis tests according to the Australian standard AS1038method. The chemical analysis of the biochar was undertaken in a NATA (National Association of Testing Authorities,Australia)accredited facility using ISO17025.Total C and N were measured by Dumas combustion method using an ELEMENTAR Analysensysteme Vario MAX CN analyzer with combustion chamber set at900 C and oxygenflow rate of125ml minÀ1.The pH was measured in0.01M CaCl2(1:5)according to method4B2of Rayment and Higginson (1992).Available phosphorus(Colwell),mineral nitrogen(KCl extraction)and DTPA-extractable micronutrients were measured according to methods9B1,7C2and12A1of Rayment and Higginson (1992)respectively.For elemental compositions and metals anal-ysis,0.25g dried and ground sample is weighed into a microwave vessel.Nitric acid and peroxide are added and the sample is digested using microwave assisted acid digestion.Samples are made up to25ml with type1water and analyzed by ICP-AES according to USEPA6010method.2.3.FTIR analysisThe Fourier Transformation Infrared(FTIR)spectra of powdered samples were recorded in Nicolet6700FTIR spectrometer applying Attenuated Total Reflectance(ATR)method with diamond crystal. The total number of scans was32with spectral resolution of 4cmÀ1.Omnic Spectra software was used to assist with interpre-tation of some of the data.2.4.Statistical analysisUnivarite analysis(ANOVA)and post-hoc Student e Newmans e Kules(SNK)test were performed using GMAV5(Underwood and Chapman,1989)to determine the significance of differences in the concentrations of the elements in the wastewater sludge bio-char produced at different temperatures.Data was tested for homogeneity of variance using Cochran’s test.2.5.Relative enrichment of elements in biocharTo understand the volatile nature under combustion conditions, relative enrichment(RE)factors are calculated:RE¼Elemental concentration in biocharElemental concentration in sludgeÂbiochar yield100 Relative enrichment factors help to identify the degree of enrichment of elements in the biochar and reveal the volatility of trace elements.RE factors in biochar greater than1indicate larger enrichment of the trace element in the biochar,while when RE factors are less than1then the elements exhibit volatilisation.3.Results and discussion3.1.Biochar yieldBiochar yield decreased with increasing pyrolysis temperature from72.3%of the original feedstock mass at300 C,63.7%at400 C, 57.9%at500 C and52.4%at700 C(Table1).The rate of weight loss was the most rapid at300 C,which is the temperature of torre-faction,losing approximately27%of the initial mass.At tempera-tures from300 C to400 C the biochar yield decreased by8.6%, while heating from500 C to700 C decreased by additional5%.3.2.Changes in chemical bond structure with pyrolysis temperatureThe infrared spectra of the sludge and biochar samples,revealed their complex chemical bond structure consisting of mixture of mineral and organic matter(Fig.1).The two sharp peaks at about 3700cmÀ1and3600cmÀ1corresponding to vibration of OH groups in the mineral matter.Unlike OH and NH vibrations which comeTable1Means and standard errors of biochar yields produced at different temperatures.300 C400 C500 C700 C Biochar yield72.3%63.7%57.9%52.4%Æ2.5Æ2.0Æ2.3Æ2.6M.K.Hossain et al./Journal of Environmental Management92(2011)223e228 224from organic matter (maximum peak at 3276cm À1)the inorganicOH groups are still detected in the sample treated at 700 C.The intensity of peak at 3276cm À1decreases rapidly from raw material sample to sample heated at 300 C suggesting that organic OH and NH groups are very unstable at elevated temperatures.The bands at 2954cm À1and 2847cm À1correspond to aliphatic CH 3asymmetric and symmetric stretching vibration respectively,which are also con firmed by scissoring CH 2vibration at 1432cm À1.These bands are absent in samples heated at 400 C and above.Methyl groups (CH 3)similar to OH and NH groups are the weakest functional groups and break at low temperatures.The cleavage of these groups is contributing to higher mass loss during thermal decomposition and gas product evolution.The stretching vibration of C e H bond in aromatic structures is visible as a band at around 2924cm À1.Aromatic and heteroaromatic compounds are also con firmed by C e H wagging vibrations in the region between 800and 600cm À1.The intensity of these peaks increases for samples treated at 300 C and higher temperatures which indicates stability of the aromatic and heteroaromatic compounds and possible cyclisation.Presented results suggest that decomposition of nitrogen organic structure,such as amine and amides,takes place at temperature below 300 C.The broad band corresponding to vibration of O e H groups at around 3390and C e N e C bending vibration at 1544cm À1are present only in raw samples.The bands below 600cm À1are due to M e X stretching vibrations in both organic and inorganic halogens compounds (M-metal,X-halogen).The main difference between the FTIR spectra of the wastewater sludge biochar from this work and biochars produced from woody materials (Mulligan et al.,2010),is in the presence of organic nitrogen and metallic compounds in the sludge biochar.3.3.Agronomic propertiesAs expected pyrolysis temperature affected the agronomic properties of wastewater sludge biochar as shown in Table 2.The volatile matter decreased from 50.2%for the raw sludge,33.8%for the biochar prepared at 300 C to 15.8%at 700 C.The fixed carbon was in similar order for all samples,while the ash concentration in the biochar signi ficantly increased with the pyrolysing temperature.The biochar was acidic when produced at lower treatment temperatures,shifting to alkaline at 700 C.At 500 C the pH of the biochar was almost neutral (7.27).The electrical conductivity (EC)increased slowly with temperature of up to 500 C but at higher temperatures it was reduced by almost a half.The electrical conductivity,a parameter used to estimate the amount of totaldissolved salts in the sample,was 11.95dS m À1for the raw sample,while signi ficantly decreasing with the pyrolysis temperature.3.4.Major nutrientsThe amount of total N and NH 4-N was found to be higher for low treatment temperatures and decreased with temperature (Table 2).Rapid loss of organic OH and NH groups from organic matter of wastewater sludge for temperature above 400 C was also con firmed by the FTIR spectra (Fig.1).Available phosphorus (Col-well P)was high at 400 C and decreased with the temperature.Pyrolysis temperature had little effect on NO 3-N,at 300 C and 400 C measuring below the detection limit,however above 500 C it increased by small amounts.3.4.1.NitrogenTotal N content of wastewater sludge biochar decreased by 55%when the temperature was increased from 300 C to 700 C (Fig.2).This may be due to the volatilisation of nitrogen during pyrolysis (Bagreev et al.,2001;Gaskin et al.,2008).Shinogi (2004)also reported a decrease of total N in the biochar produced from sewage sludge at higher temperatures.Nitrogen is removed through loss of the NH 4-N and NO 3-N fraction as well as the loss of volatile matter containing N groups at temperature of 200 C,but with increased temperature (>600 C)it is gradually transformed into pyridine like structure (Bagreev et al.,2001).Our study indicates that relatively high proportion of nitrogen is still conserved at low pyrolysis5001000150020002500300035004000Wavenumber (cm -1)500o C 400oC 700o C RS300o C Fig.1.FTIR spectra of wastewater sludge and sludge biochar prepared at differenttemperatures (RS e raw sludge).Table 2Proximate,ultimate and agronomic properties of wastewater sludge and sludge biochar at various temperatures.UnitWastewater sludgeSludge biochar 300 C400 C 500 C 700 CMoisture %7.6 4.3 4.2 3.5 3.4Ash %3452.863.368.272.5FC %8.29.1 6.87.68.3VM %50.233.825.720.715.8C %32.325.620.220.320.4H % 4.47 2.55 1.280.880.51N % 3.27 3.32 2.40 2.13 1.20O %18.368.33 4.610.650.00pH pH Unit 4.425.32 4.877.2712ECds m À111.95 4.12 4.15 4.7 2.5Colwell Pmg kg À1747.5492.5740567.5527.5KCl extrac.NH 4-N mg kg À172751175142.525 1.34KCl extrac.NO 3-N mg kg À135<0.2<0.20.240.32FC ¼fixed carbon,VM ¼volatile matter,O%calculated bydifference.1234525300400500700Temperature (o C)T o t a l n u t r i e n t c o n t e n t (%)Fig.2.Changes in total N,P and K concentration in wastewater sludge samples and to produce biochars at different temperatures.Values at 25 C indicate the raw waste-water sludge.All other temperatures indicate wastewater sludge biochar concentrations.M.K.Hossain et al./Journal of Environmental Management 92(2011)223e 228225temperatures (Fig.2).The ammonium nitrogen (NH 4-N)and nitrate nitrogen (NO 3-N)are important agronomic properties because these are the main sources of available N for plant uptake.The NO 3-N present in the studied biochar samples is very low ranging from less than detection limit (0.2)to 0.32mg kg À1(Table 2).Ammonium nitrogen concentrations in biochar are higher than NO 3-N.Ammo-nium nitrogen concentrations decreased rapidly with increasing temperature.Ammonium nitrogen at 300 C measured at 1175mg kg À1was reduced to 143mg kg À1at 400 C,suggesting that available nitrogen content in the form of NH 4-N is higher in wastewater sludge biochars produced at lower pyrolysis (<400 C)temperatures.It is very unlikely that total N present in the biochar is fully available for plant uptake as it is organically bonded in recal-citrant forms (Chan and Xu,2009).While there is limited data on the plant availability of nitrogen in biochars,previous work conducted by Chan et al.(2007)on poultry litter biochar found only 2mg kg À1of available nitrogen (NH 4-N plus NO 3-N),which is in the same range as the nitrogen measured at the higher pyrolysis tempera-tures in this work.3.4.2.PhosphorusThe total P content in the wastewater biochar increased by 43%when pyrolysed at a temperature of 700 C indicating phosphorus is associated with the inorganic fraction of the wastewater sludge (Fig.2).This finding showed similar increasing trend to the reported increase of phosphorus with temperature from 5.6%at 250 C to 12.8%at 800 C in biochar produced from sewage sludge (Chan and Xu,2009).Bridle and Pritchard (2004)also discussed the full recovery of P in biochar produced from sewage sludge at 450 C.Concentration of P in the wastewater sludge biochar will depend on the wastewater treatment process.For example during primary sedimentation phosphate is removed primarily by settling of insoluble precipitates and therefore primary sludges contain mostly inorganic P forms (Pastene,1981).The wastewater sludge sample in this work was a sludge produced after a secondary treatment process,hence the phosphorus content was low.The plant available P (Colwell phosphorus)in the biochar varied from 492.5mg kg À1to 527.5mg kg À1at a temperature of 300 C and 700 C respectively.3.4.3.PotassiumA very little amount of total potassium was present in the wastewater sludge biochar (Fig.2).Potassium was found to increasein concentration with increasing temperature mainly because of the inorganic association of potassium with the wastewater sludge.Biosolids commonly contain small amounts of K (0.1e 0.6%)as indicated previously by Cogger et al.(2006).3.5.Other nutrientsTable 3shows that total concentration of the other nutrient elements present in the wastewater sludge and sludge biochar.The nutrients Ca,Fe and Zn signi ficantly increased with increasing pyrolysis temperature.There are no signi ficant differences in the total concentration of Cu between the temperature of 300 C and 400 C but concentration varies signi ficantly between the biochars produced at temperatures 400 C,500 C and 700 C.In the case of Mg concentration varies signi ficantly for biochars produced at 300 C and 400 C and 500 C and 700 C.The concentration of S varies signi ficantly only between the temperatures of 400 C and 500 C.The variability of the micronutrients with temperature is due to their volatility and effect of pyrolysis temperature on both composition and chemical structure of the biochar (Chan and Xu,2009).Consid-ering relative enrichment factors for the elements from Table 3,sulphur exhibited the highest volatility losing 40%of its initial sulphur content,while Cu exhibited almost insigni ficant volatility.3.6.Trace elementsA range of trace elements present in the biochar are shown in Table 4.The concentration of As and Se was below the detection limit in the sludge and all biochars.The concentrations of all the other elements were signi ficantly higher in the biochar samples than raw sludge (Table 4).Concentration of Cd in the biochar was found to increase with increasing temperature.Concentration of Pb,Ni and Cr was enriched in the biochar at temperatures of up to 500 C then they decreased at 700 C indicating partial defractio-nation and/or devolatilisation of these metals at elevated temper-atures.RE factors indicated the largest volatility for Cr at 700 C with a loss of 50%of its initial concentration.3.7.DTPA available metal elementsThe trace elements present in biochar may not be entirely available for plant uptake.DTPA (diethylene triamine pentaaceticTable 3Means,standard deviations and RE factors for the total nutrient concentrations of wastewater sludge and biochars.Elements Description Units RS 300 C 400 C 500 C 700 C CaMean %3.02 3.474.17 4.625.35SD Æ0.06Æ0.15Æ0.02Æ0.12Æ0.10RE 0.80.90.90.9Fe Mean %6.177.88.8510.1511SD Æ0.06Æ0.09Æ0.08Æ0.28Æ0.00RE 0.90.90.950.95Mg Mean %0.330.350.430.460.54SD Æ0.01Æ0.01Æ0.01Æ0.01Æ0.01RE 0.80.80.80.9S Mean %5.17 4.47 4.72 5.96.17SD Æ0.02Æ0.15Æ0.04Æ0.19Æ0.19RE 0.60.60.70.6CuMean mg kg À18101150112513251500SD Æ12.90Æ28.86Æ25Æ25Æ70.71RE 10.90.91ZnMean mg kg À113501675182521002175SD Æ28.86Æ25Æ25Æ0.00Æ25RE0.90.90.90.8RS ¼raw sludge;SD ¼standard deviation;RE ¼relative enrichment factor;Æ0.00indicates results were near instrument detection limit.M.K.Hossain et al./Journal of Environmental Management 92(2011)223e 228226acid)extraction method is a technique used to estimate the readily available concentration of elements for plant uptake.In this work the availability of some trace elements(Cd,Cu,Fe,Mn and Zn)in biochars was compared for different pyrolytic temperatures using this method(Table5).DTPA-extractable concentrations of all the elements(with the exception of Fe)in the biochars were lower than those in the original raw wastewater sludge samples.The process of pyrolysis appears to reduce the bioavailability of many of these trace elements.The greatest DTPA Cu concentrations were seen at400 and500 C.The highest availability of Fe and Zn was detected at a temperature of300 C and decreased with increasing tempera-ture.Considering the total concentration of these two elements is enriched in the biochar(Table2),results of the DTPA test suggest that high pyrolysis temperature reduces bioavailability of Fe and Zn.The available concentration of Mn is significantly different between the temperature of300 C and400 C but there is no significant difference between400 C and500 C.The bioavailable concentration range of Cu and Cd is low for almost all temperatures. Availability of Cu at temperatures of300 C and700 C and Cd for all temperatures except for400 C was below the detection limit.Variation in the DTPA concentration with increasing temperatures of these trace elements reflects the changes in their chemical forms during the pyrolysis process.4.ConclusionsPyrolysis temperature has significant effect on the chemical properties of the biochar produced from wastewater sludge in this work with important implications regarding their suitability as a soil amendment.A wide range of elements important for crop cultivation are present in the biochar,such as N,P,K and micro-nutrients.The study confirmed that the yield of biochar decreases with increasing pyrolysis temperature.The study also shows that wastewater sludge biochar produced at low temperatures(300 C, 400 C)is acidic whereas at high temperature(700 C)it is alkaline in nature.This is an importantfinding as the agricultural use of biochar can have a twofold application.If the soil intended for biochar application is acidic in nature,then the biochars produced at700 C or higher temperatures can be used to neutralize the soil, improve soil fertility and sequester carbon.On the other hand biochars produced at lower temperatures might be suitable for alkaline soils to correct for alkalinity problems.For the biochar produced in this work,the concentration of N and particularly in its available form for plant uptake was found to be very low and decreased with temperature.Attention is needed when biochars very low in mineral nitrogen are applied to agri-cultural and supplementation with nitrogenous fertilisers may be required for adequate plant nutrition.On the other hand,concen-tration of all micronutrients(Ca,Fe,Mg,S,Cu and Zn)as total elements was found to increase with increasing temperature. Pyrolysis temperature also had an effect on enrichment of heavy metals(Zn,Pb,Ni and Cd)in the produced biochar,which is important consideration as the heavy metals can bioaccumulate when biochars are applied to the soil.Arsenic and selenium in the wastewater sludge biochar used in this work were below the detection limit.However,DTPA-extractable concentrations of some of these elements were found to decrease with increasing pyrolysis temperature and therefore this indicates a tendency of these elements to become less available to plants.Our results indicate there is a great potential to convert waste-water sludge to biochar in order to improve the management of this waste,reduce its transport costs and reduce the production volume.Produced biochar may serve as a valuable soil amendment by supplying plant nutrients and other benefits including carbon sequestration.Our results further highlight the potential to improve the quality,hence the agronomic value and minimize the potential harmful effects of the biochars by controlling the pyrol-ysis temperature.It is especially very important to have a better understanding of the mobility and bioavailability of the trace elements present in the biochar,beforefield trials are attempted. AcknowledgementsThe authors gratefully acknowledge thefinancial support for this research provided by the Higher Degree Research Unit,Mac-quarie University,Sydney,Australia.The authors also wish to thank the Sydney Water for supply of wastewater sludge samples for the study.ReferencesBagreev,A.,Bandosz,T.J.,Locke,D.C.,2001.Pore structure and surface chemistry of adsorbents obtained by pyrolysis of sewage derived fertilizer.Carbon39, 1971e1979.Table4Means,standard deviations and RE factors for total metal concentrations in mg kgÀ1present in wastewater sludge and biochars.Metals RS300 C400 C500 C700 CAs<3<3<3<3<3Cd Mean 2.07 2.62 2.8 3.17 3.22SDÆ0.06Æ0.04Æ0.05Æ0.12Æ0.06RE0.90.90.90.8Cr Mean81107.5112.5112.583SDÆ0.70Æ2.50Æ2.50Æ2.50Æ3.36RE10.90.80.5Ni Mean70182.5165292.5195SDÆ0.91Æ18.42Æ11.9Æ34.24Æ6.45RE 1.9 1.5 2.4 1.5Pb Mean86.5115130140132SDÆ1.04Æ2.88Æ0.00Æ0.00Æ2.5RE110.90.8Se<6.6<6.6<6.6<6.6<6.6RS¼raw sludge;SD¼standard deviation;RE¼relative enrichment factor;Æ0.00indicates results were near instrument detection limit.Table5Means,standard errors and RE factors for DTPA available trace element concentra-tions in mg kgÀ1in wastewater sludge and biochar.Elements RS300 C400 C500 C700 CCu Mean22.75<0.114.7517.25<0.1SDÆ4.64Æ1.93Æ2.49RE0.40.4Fe Mean467.5842.5390.00342.5212.5SDÆ17.97Æ158.44Æ4.08Æ15.47Æ6.29RE 1.30.50.40.2Mn Mean51.0036.0013.0024.000.11SDÆ10.68Æ0.81Æ0.70Æ2.34Æ0.01RE0.50.20.30Zn Mean297.5142.583.552.50.11SDÆ59.91Æ4.78Æ5.42Æ5.85Æ0.01RE0.30.20.10Cd Mean0.15<0.10.20<0.1<0.1SDÆ0.01Æ0.01RE0.8RS¼raw sludge;SD¼standard deviation;RE¼relative enrichment factor.M.K.Hossain et al./Journal of Environmental Management92(2011)223e228227。

污泥低温干化处理工艺流程1.污泥低温干化处理是一种环保的污泥处理技术。

Low-temperature drying process for sludge is an environmentally friendly sludge treatment technology.2.工艺流程包括预处理、干化、冷却、破碎和包装等环节。

The process includes pre-treatment, drying, cooling, crushing, and packaging.3.首先，污泥需要经过脱水处理，使含水量降低到一定程度。

First, the sludge needs to be dewatered to reduce the moisture content to a certain level.4.然后，通过输送带将脱水后的污泥送入干化设备中。

Then, the dewatered sludge is fed into the drying equipment by a conveyor belt.5.在干燥设备中，污泥通过加热和对流加热的方式进行干化处理。

In the drying equipment, the sludge is dried by heating and convection heating.6.干化过程中，要保持适当的温度和湿度，以确保干燥效果。

During the drying process, the proper temperature and humidity should be maintained to ensure the drying effect.7.干化后的污泥经过冷却处理，使其温度适宜后进行下一步处理。

The dried sludge is cooled to an appropriate temperature for the next step of treatment.8.冷却后的污泥需要经过破碎处理，使其颗粒大小适合包装和运输。

气候变迁：降水量与温度的关系探究Climate Change: Exploring the Relationship between Precipitation and TemperatureIn the ever-evolving realm of climate science, the intricate relationship between precipitation andtemperature stands as a pivotal aspect of global meteorological patterns. As the world witnesses unprecedented changes in weather patterns, understandingthe dynamic dance between these two elements becomes increasingly crucial. This essay delves into the complexities of this relationship, examining how variations in temperature affect precipitation patterns and vice versa. The fundamental connection between precipitation and temperature lies in the laws of thermodynamics. As temperature rises, air expands, carrying more moisture.This moisture, in turn, condenses into clouds, which eventually release precipitation. Conversely, colder temperatures cause air to contract, reducing its capacityto hold moisture, often leading to dryer conditions. However, this relationship is far from straightforward, asmultiple factors influence the precipitation-temperature nexus.One significant factor is the influence of atmospheric circulation patterns. Changes in wind patterns and air masses can significantly alter the distribution of precipitation, even in regions where temperature changes are minimal. For instance, changes in the monsoon system, which brings rain to much of Asia, can lead to significant fluctuations in precipitation, despite relatively stable temperatures.Geographical location also plays a crucial role. For instance, regions near the equator experience high temperatures year-round but vary widely in precipitation patterns. Conversely, polar regions experience extreme cold but have their own unique precipitation patterns, such as snowfall.Human activity, particularly the emission of greenhouse gases, has also had a profound impact on global temperature and precipitation patterns. Rising temperatures due to climate change have led to more frequent and intense extreme weather events, including heavy rainfall anddroughts. These changes have had far-reaching impacts on agriculture, water resources, and ecosystems worldwide.In conclusion, the relationship between precipitation and temperature is complex and multifaceted. Understanding this relationship is crucial for predicting and adapting to future climate change. As the world continues to warm, it is essential to monitor and study these patterns tomitigate the potential impacts of climate change and ensure a sustainable future for all.**气候变迁：降水量与温度的关系探究**在气候科学不断演变的领域中，降水量与温度之间错综复杂的关系成为全球气象模式的关键方面。

本文由【中文word文档库】搜集整理。

中文word文档库免费提供海量教学资料、行业资料、范文模板、应用文书、考试学习和社会经济等word文档李玉友，男，1961年出生，昌乐县鄌郚镇不西李家庄人，1978年昌乐（高崖）二中毕业，同年考入西安冶金建筑学院，后留学日本。

现为日本国立东北大学副教授，天津市特聘讲座教授，主要从事污水生物净化及资源回收利用技术研究。

现任日本水环境学会厌氧生物处理研究委员会干事、期刊《城市清扫》(日本)编委论文审查委员、日本环境工程教授协会干事、日本土木学会学报环境部门编委、2nd International Workshop on Innovative Anaerobic Technology (2004, Sendai, Japan)组织干事、期刊《环境技术》(日本)编委、期刊《环境科学学报》(中国)编委、日本能源学会·生物质能源教材编写及普及委员会委员、日本废弃物学会第16次学术年会执行委员、日本水环境学会第40次学术年会执行委员。

学习简历∶博士, 1990, 日本东北大学 (Tohoku University) 土木系, 污染控制专业。

硕士, 1985, 天津大学土木系环境工程专业。

学士, 1982, 西安冶金建筑学院(西安建筑科技大学)环境工程系, 给水排水专业。

日本技术士会注册工程师2个(2000年卫生工程部门, 2002年上下水道部门)工作简历∶2003–至今, 日本东北大学土木工程系环境工程副教授2001–2003, 日本ATAKA工业株式会社·环境研究所主管研究员1996–2001, 日本ATAKA工业株式会社·技术研究所主任研究员1993–1996, 日本东北大学土木工程系环境工程副教授1992–1993, 香港大学土木工程系研究助理1987–1992, 日本东北大学土木工程系环境工程助教学术论文：1.城市垃圾厌氧甲烷发酵的中温和高温处理的比较，日本土木学会环境工程研究讨论会优秀论文奖，20002.Application of membrane technology in the treatment of night soil and sludge，Environmental Technology，2006, 47(3)3.Recent development of biomethanation technology，Journal of Japan Society on Water Environment, 2004, 27(10)4.High-Rate Methane Fermentation of Lipid-Rich Food Wastes by a High-Solids Co-digestion Process. Water Science and Technology. 2002.125.High-rate methaneation of the food waste and garbage by a two-phase process with circulation of digested sludge. Environmental Engineering Research. 20036.Recent development of biomethanation technology. Journal of Japan Society on Water Environment 2004.107.Application of membrane technology in the treatment of night soil and sludge. Environmental Technology. 2006.37.Influence of sludge ratio and temperature on the integrated methane fermentation of organic fraction of municipal solid waste and biosolids. Journal of Environmental System and Engineering，20038.Dilution-free treatment of the food processing waste by a two-phase circulating methane fermentation process. Environmental Engineering Research，20049.Analysis of the hydrogen fermentation microbial community by using PCR-DGGE methods. Journal of Environmental System and Engineering，200510.Characteristics of hydrogen and methane fermentation of potato processing waste by two-phase circulating process without dilution water . Journal of Japan Society on Water Environment 200511.Renewable Energy Production from Organic Wastes byHigh-Solid Methane Fermentation. The Proceedings of ENERGY & ENVIRONMENT : AWorld of Challenges and Opportunities2003 parison of ammonia inhibitionBetween the meshophilic and thermophilic anaerobic digestion of municipal solid wastes. The Proceedings of 10th World Congress on Anaerobic Digestion，200413.A new two-phase process for waterless methanefermentation treating the organic fraction of MSW. Proceedings of 4th International Symposium on Anaerobic Digestion of Solid Waste (Copenhagen, Denmark)，2005科研项目：1.氢发酵和甲烷发酵两相循环工艺的研究，日本教育科技部•科研基金(基础研究B)，2006.4-2008.3，主持人2.产氢产乙醇复合发酵变生物质为生物能源的探索研究（萌芽研究)，日本教育科技部•科研基金，2006.4-2009.3，主持人3.下水污泥厌氧消化的研究项目，日本农业部NEDO，2006.4-2009.4，主持人专利：1.废弃物处理方法（DMF工业废水的生物处理新方法），2004.9.24，日本专利第3600220号2.含油废水和废弃物的处理方法，2004.10.22，日本专利第3609332号。

第30卷第6期2022年12月V ol.30 No.6Dec.2022安徽建筑大学学报Journal of Anhui Jianzhu UniversityDOI：10.11921/j.issn.2095-8382.20220609低热-NaOH联合处理剩余污泥释放碳源的效果唐玉朝1，2，蔡丽丽1，2，陈 园1，2，刘 俊3（1. 安徽建筑大学 环境与能源工程学院，安徽 合肥 230601；2. 环境污染控制与废弃物资源化利用安徽省重点实验室，安徽 合肥 230601；3. 安徽中环环保科技股份有限公司，安徽 合肥 230071）摘 要：为了研究低热-NaOH联合处理剩余污泥，获得胞内碳源释放的最佳方案，测定破解后污泥上清液中的SCOD、蛋白质和多糖浓度，分析其随NaOH投加量、水浴温度、以及反应时间的变化。

结果表明，低热-NaOH联合处理剩余污泥的最佳条件是NaOH投加量3.0 g/L、水浴温度60 ℃、反应时间24 h。

在此条件下，上清液中SCOD、蛋白质和多糖浓度分别达18 341.4 mg/L、1 434.53 mg/L、324.8 mg/L。

经污泥破解前后粒度对比分析，污泥破解前后中值粒度分别为30.2 μm和8.71 μm，相差荧光显微镜观显示污泥絮体被破坏。

研究显示，低热-NaOH联合处理可在较低能耗下充分释放剩余污泥碳源，研究结果可为优化热碱法预处理剩余污泥提供 依据。

关键词：低热；NaOH；剩余污泥；SCOD中图分类号：X703 文献标识码：A 文章编号：2095-8382（2022）06-062-06Effect of Low Temperature Thermal and NaOH Treatment on Carbon Release fromExcess SludgeTANG Yuchao1，2，CAI Lili1，2，CHEN Yuan1，2，LIU Jun3（1. School of Environment and Energy Engineering，Anhui Jianzhu University，Hefei 230601，China；2. Anhui Provincial Key Laboratory of Environmental Pollution Control and Resource Reuse，Hefei 230601，China；3. Anhui Zhonghuan Environmental Protection Technology Co.LTD，Hefei 230071，China）Abstract：To study the optimal scheme to obtain the intracellular carbon release from excess sludge with low temperature thermal and NaOH treatment，the concentrations of SCOD， protein and polysaccharide in the treated sludge supernatant were determined，and their relationship with NaOH dosage，water bath temperature and reaction time were analyzed. The results show that the optimal scheme of low grade fever and NaOH treatment for the excess sludge were a NaOH dosage of 3.0 g/L，a water bath temperature of 60 ℃，a reaction time of 24 h，and the concentrations of SCOD，protein and polysaccharide in the supernatant reached 18 341.4 mg/L，1 434.53 mg/L and 324.8 mg/L，respectively. The median particle size before and after sludge treatment was 30.2 μm and 8.71 μm， respectively. The phase-contrast and fluorescence microscopy showed that the floc sludge was destroyed. The study proved that the combined low temperature thermal and NaOH treatment can fully release the carbon of excess sludge with low energy consumption，and provides references for optimizing the thermo-alkaline pretreatment of excess sludge.Keywords：low thermal；NaOH；excess sludge；SCOD收稿日期：2021-07-08基金项目：国家自然科学基金项目（51978003；51578002）作者简介：唐玉朝（1975-），男，副教授，博士，主要研究方向为水处理理论与技术； 蔡丽丽（1996-），女，硕士研究生，主要研究方向为水处理理论与技术。

陈德会，杜环兴，李山海，等. 贮藏温度变化对壳蛋新鲜度的影响[J]. 食品工业科技，2023，44（7）：337−342. doi:10.13386/j.issn1002-0306.2022060274CHEN Dehui, DU Huanxing, LI Shanhai, et al. Effect of Storage Temperature Change on Freshness of Shell Eggs[J]. Science and Technology of Food Industry, 2023, 44(7): 337−342. (in Chinese with English abstract). doi: 10.13386/j.issn1002-0306.2022060274· 贮运保鲜 ·贮藏温度变化对壳蛋新鲜度的影响陈德会1，杜环兴1, +，李山海1，雷　琴1，张　静1，常海军2，戴　妍1,*（1.重庆化工职业学院环境与质量检测学院，重庆 401228；2.重庆工商大学环境与资源学院，重庆市特色农产品加工储运工程技术研究中心，重庆 400067）摘　要：该文以新鲜罗曼粉壳蛋为研究对象，研究4个贮藏温度变化处理组壳蛋新鲜度指标的变化，分别于0、10、20、30 d 检测所有实验组壳蛋失重率、气室高度、哈夫单位、蛋黄指数、浓稀蛋白比和蛋清pH 。

结果表明，贮藏10~30 d ，处理组2、处理组3、处理组4的失重率显著升高（P <0.05），而气室高度和浓稀蛋白比显著降低（P <0.05），除对照组外，所有处理组壳蛋pH 呈现先升高后下降的趋势，处理组3和处理组4的蛋黄指数下降趋势更为明显。

对照组和处理组1壳蛋的哈夫单位、蛋黄指数和浓稀蛋白比显著高于（P <0.05）处理组3和处理组4。

在贮藏10~20 d 时，处理组2的壳蛋pH 显著高于（P <0.05）对照组和处理组1。

森林降温效应英文作文The forest cooling effect is a phenomenon where the temperature in a forested area is lower than in surrounding areas. This is due to the shade provided by the trees and the evaporation of water from the leaves, which helps to cool the air.When the sun shines on the trees, the leaves absorb the sunlight and use it for photosynthesis, which is the process of converting carbon dioxide and water into oxygen and glucose. This process helps to cool the air because the energy from the sun is being used by the trees, rather than heating up the surrounding environment.In addition to the shade and evaporation of water, the trees in a forest also release compounds called volatile organic compounds (VOCs) into the air. These compounds can react with other pollutants in the atmosphere to form particles that can scatter sunlight and help to cool the air.The cooling effect of forests can have a significant impact on local climate, as well as on the global climate. In urban areas, where there is a lot of concrete and asphalt, the temperature can be several degrees higher than in rural areas with more vegetation. By planting more trees and preserving existing forests, we can help to mitigate the effects of climate change and create more comfortable living environments.In conclusion, the forest cooling effect is an important natural phenomenon that helps to regulate temperature and create more comfortable environments for both humans and wildlife. By understanding and appreciating the role of forests in cooling the air, we can work towards protecting and preserving these valuable ecosystems for future generations.。

关于降水量与温度的模板英语作文The Relationship between Precipitation and TemperatureIntroductionThe relationship between precipitation and temperature is a topic that has garnered significant interest in the field of climatology. While it is well known that precipitation and temperature are both key components of the Earth's climate system, the ways in which they interact and influence one another are still not fully understood. In this essay, we will explore the relationship between precipitation and temperature, discussing the various mechanisms through which these two factors interact and affect one another.The Impact of Temperature on PrecipitationTemperature plays a crucial role in determining the amount and type of precipitation that occurs in a given region. Warmer temperatures can lead to increased evaporation of water from the Earth's surface, which in turn can lead to higher levels of atmospheric moisture. This increase in atmospheric moisture can result in more frequent and intense precipitation events, as the excess moisture condenses and falls back to the Earth in the form of rain, snow, or other types of precipitation.Conversely, colder temperatures can lead to decreased evaporation and lower levels of atmospheric moisture, which can result in drier conditions and reduced precipitation. In regions where temperatures are consistently low, the lack of moisture in the atmosphere can lead to arid or desert-like conditions, with little to no precipitation occurring for extended periods of time.The Impact of Precipitation on TemperatureJust as temperature can influence precipitation, precipitation can also have an impact on temperature. One way in which precipitation can affect temperature is through the process of evaporation. When precipitation falls to the Earth in the form of rain or snow, it can help to cool the Earth's surface through evaporation. This cooling effect can help to lower temperatures in the immediate vicinity of the precipitation event, providing relief from the heat in hot and humid climates.Additionally, precipitation can also help to moderate temperatures over larger geographical regions. The presence of moisture in the atmosphere can act as a natural barrier to temperature extremes, helping to keep temperatures more stable and reducing the likelihood of extreme heatwaves or cold snaps. In this way, precipitation plays a crucial role in regulatingthe Earth's climate and maintaining a relatively stable temperature regime.ConclusionIn conclusion, the relationship between precipitation and temperature is a complex and multifaceted one, with each factor exerting a significant influence on the other. By understanding the ways in which precipitation and temperature interact and affect one another, we can gain valuable insights into the dynamics of the Earth's climate system and better predict and respond to changes in weather patterns and climatic conditions. As we continue to study and observe the relationship between precipitation and temperature, we will undoubtedly uncover new insights and discoveries that will help us better understand and adapt to the ever-changing climate of our planet.。

氨氮转化率1. 简介氨氮转化率是指在特定条件下，氨氮从一种形态转化为另一种形态的速率。

氨氮是水体中常见的一种污染物，它来自于农业、工业和生活废水等多个来源。

氨氮对水体生态系统和人类健康都具有潜在的危害，因此控制和监测氨氮转化率对于环境保护至关重要。

2. 氨氮的来源和形态2.1 来源•农业：农田施肥、养殖废水等。

•工业：化肥生产、石油加工等。

•生活废水：家庭污水、城市排水等。

2.2 形态•氨（NH3）：无色、刺激性强的气体。

•高铵盐（NH4+）：在酸性条件下存在，主要以离子形式存在。

•氨基酸（R-NH2）：有机物中含有NH2基团。

3. 氨氮的转化途径3.1 氧化作用3.1.1 化学反应NH3 + O2 → NO2- + H2O + H+3.1.2 生物反应氨氧化细菌（Ammonia-oxidizing bacteria）将NH3氧化成亚硝酸（NO2-），再由亚硝酸细菌（Nitrite-oxidizing bacteria）将亚硝酸氧化成硝酸（NO3-）。

3.2 还原作用3.2.1 化学反应NO3- + 5e- + 4H+ → NH4+ + 2H2O3.2.2 生物反应反硝化细菌（Denitrifying bacteria）将硝酸还原为氮气（N2）。

4. 影响氨氮转化率的因素4.1 温度温度对氨氮转化率有明显影响，一般情况下，随着温度的升高，转化速率加快。

4.2 pH值pH值对不同形态的氨氮转化有不同的影响。

在弱碱性条件下，NH3的浓度较高；在弱酸性条件下，NH4+的浓度较高。

4.3 溶解氧浓度溶解氧浓度对于氨、亚硝酸和硝酸的转化过程中的氧化反应至关重要。

较高的溶解氧浓度有利于氨氮转化为亚硝酸和硝酸。

4.4 有机负荷有机负荷是指废水中有机物的含量，过高的有机负荷会抑制氨氮的转化过程。

5. 氨氮转化率的监测方法5.1 化学分析法常用的化学分析方法包括：纳氏试剂法、蒸馏-滴定法、纳斯塔试剂法等。

5.2 生物传感器生物传感器是利用生物体对特定物质作出响应的原理制成的一种检测装置。