Determination of low chemical oxygen demand values in water by the dichromate semi-micro method
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化学分析计量CHEMICAL ANALYSIS AND METERAGE第30卷,第6期2021年6月V ol. 30,No. 6Jun. 202162doi :10.3969/j.issn.1008–6145.2021.06.014酸化吹气–重铬酸钾法测定高氯地表水中化学需氧量达莉芳,范丽华,施玉格,段小燕,李刚,李媛,贺承启(新疆维吾尔自治区生态环境监测总站,乌鲁木齐 830011)摘要 建立酸化吹气–重铬酸钾法测定高氯地表水化学需氧量(COD Cr )的方法。
通过在高氯水样中加入适宜浓度的硫酸,在加热及吹气条件下使干扰物氯离子以氯化氢的形式释放出,并用氢氧化钠溶液吸收,再采用重铬酸盐法对驱氯后的样品进行COD Cr 的测定。
结果表明,在优化条件下,当取样体积为10.0 mL 时,本方法的检出限为4 mg /L ,测定结果的相对标准偏差为5.2%~13.5%(n =6),与理论值的相对误差为–2.0%~4.3%。
该方法适用于氯离子质量浓度为1 000~100 000 mg /L 的地表水中化学需氧量的测定。
关键词 氯;地表水;化学需氧量;酸化吹气–重铬酸钾法中图分类号:O661.1 文献标识码:A 文章编号:1008–6145(2021)06–0062–05Determination of chemical oxygen demand in high chlorine surface waterby blow–acidizing–dichromate methodDa Lifang, Fan Lihua, Shi Yuge, Duan Xiaoyan, Li Gang, Li Yuan, He Chengqi(Xinjiang Uygur Autonomous Ecological Environmental Monitoring Station, Urumqi 830011, China )Abstract A method was developed for determination of the chemical oxygen demand(CODCr) in high chlorine surface water by blow–acidizing–dichromate method. By adding sulfuric acid of speci fic concentration to the water sample with high concentration of chloride ion, the interfering chloride ion was released in the form of hydrogen chloride under heating and air blow conditions, and absorbed by sodium hydroxide solution. CODCr of the sample was determined by dichromate method after chloride removal. The results show that the detection limit of this method was 4 mg /L, the relative standard deviation of determination results was 5.2%–13.5%(n =6) and the relative error with the theoretical value was from –2.0% to 4.3% when the sample volume was 10.0 mL under optimized conditions. The method is suitable for the determination of COD Cr in surface water with the mass concentration of chloride ion between 1 000 mg /L and 100 000 mg /L.Keywords chlorine; surface water; chemical oxygen demand; blow–acidizing–dichromate method化学需氧量(COD Cr )是指在一定条件下,经重铬酸钾氧化处理时,与水样中的溶解性物质和悬浮物所消耗的重铬酸盐相对应的氧的质量浓度,以 mg /L 表示[1]。
ICS13.060Z 16 DB37 山东省地方标准DB 37/T 3737—2019高氯水质化学需氧量的测定重铬酸盐法High chlorinated water quality—Determination of chemical oxygendemand—Dichromate method2019- 12 -05发布2020-01-05实施目次前言 (II)1 范围 (1)2 规范性引用文件 (1)3 术语和定义 (1)4 方法原理 (1)5 干扰和消除 (2)6 试剂和材料 (2)7 仪器和设备 (4)8 样品采集 (5)9 分析步骤 (5)10 计算结果与表示 (7)11 精密度和准确度 (7)12 质量保证和质量控制 (8)13 废物处理 (8)14 注意事项 (8)前言本标准按照GB/T 1.1—2009给出的规则起草。
本标准由山东省生态环境厅提出并组织实施。
本标准由山东省环保标准化技术委员会归口。
本标准起草单位:山东省环境监测中心。
本标准主要起草人:王德明、王文雷、宋永超、魏征、许艳芳、刘金芝、金玲仁。
高氯水质化学需氧量的测定重铬酸盐法警告:本方法所用试剂硫酸汞剧毒,实验人员应避免直接接触。
样品前处理过程应在通风橱中进行。
1 范围本标准规定了测定高氯水质中化学需氧量的重铬酸盐法。
本标准适用于氯离子质量浓度1 000 mg/L~30 000 mg/L的地表水、生活污水及工业废水等水质化学需氧量(COD)的测定。
取样量为20.0 ml时,方法的检出限为4 mg/L,方法的测定下限为16 mg/L。
2 规范性引用文件下列文件对于本文件的应用是必不可少的。
凡是注日期的引用文件,仅所注日期的版本适用于本文件。
凡是不注日期的引用文件,其最新版本(包括所有的修改单)适用于本文件。
GB 11896 水质氯化物的测定硝酸银滴定法HJ/T 91 地表水和污水监测技术规范HJ/T 195 水质氨氮的测定气相分子吸收光谱法HJ 535 水质氨氮的测定纳氏试剂分光光度法3 术语和定义下列术语和定义适用于本文件。
《水质化学需氧量的测定重铬酸盐法》(HJ 828—2017)的实验室方法验证作者:张笑李文明来源:《河南科技》2019年第04期摘要:化学需氧量(COD)是我国实施排放总量控制的指标之一,反映了水中受还原性物质污染的程度。
本文主要对《水质化学需氧量的测定重铬酸盐法》(HJ 828—2017)的方法进行验证。
结果表明,测定的检出限为4mg/L,等于方法给出的检出限;对自控样2001117(30.2±1.9mg/L)和自控样2001116(224±8mg/L)进行了六次平行样测定,相对标准偏差分别为2.6%和3.1%,均在方法要求的5%以内,符合方法要求;相对误差分别为1.2和2,符合方法要求。
关键词:化学需氧量;方法验证;方法检查限中图分类号:X832 文献标识码:A 文章编号:1003-5168(2019)04-0146-03Method Verification in Laboratory of Water Quality-Determination ofthe Chemical Oxygen Demand-Dichromate Method (HJ828-2017)ZHANG Xiao LI Wenming(Xi’an Environmental Sanitation Scientific Research Institute,Xi’an Shaanxi 710000)Abstract: Chemical oxygen demand (COD) is one of the indicators of total emission control in our country. It reflects the degree of contamination by reducing substances in water. This paper mainly validated the method of "Determination of Chemical Oxygen Demand of Water Quality by Dichromate Method" (HJ 828—2017). The results showed that the detection limit of the method was 4mg/L, which was equal to the detection limit given by the method. Six parallel samples of the self-control sample 2001117 (30.2+1.9mg/L) and the self-control sample 2001116(224+8mg/L) were determined. The relative standard deviations were 2.6% and 3.1% respectively, which were within 5% of the method requirements and met the method requirements. The relative errors were 1.2 and 2 respectively, which met the method requirements.Keywords: COD;method verification;method check limit水中化学需氧量(COD)是衡量水质污染程度的指标之一[1]。
马鞍泵站这三根管线氯离子浓度都较高,特别是滨海水务,两次测定氯离子平均值接近4 000 mg/L ,对化学需氧量COD 测定干扰非常大。
1.2 准确测定COD 的重要性COD(chemical oxygen demand)化学需氧量是指利用化学氧化剂将水中的还原性物质(如有机物)氧化分解所消耗的氧量。
它反映水体受还原性物质污染的程度。
由于有机物是水体中最常见的还原性物质,因此,COD 在一定程度上反映了水体受到有机物污染的程度。
COD 越高,表明水体中还原性物质越高,而还原性物质可降低水体中溶解氧的含量,导致水生生物缺氧以至死亡,水质腐败变臭。
目前已纳入国家“十二五”减排要求中。
对绍兴水处理而言,COD 是废水处理效果控制的重要指标之一。
COD 的去除效果反映生化系统运行的好坏,而生化系统又是整个污水处理工艺的核心部分,若COD 的去除出现异常,则系统恢复难度大、时间长,对出水达标带来严峻考验;其二,公司进出水COD 波动较大,尤其是高氯废水,更需提供准确的数据为生产做好指导作用。
针对以上内容,绍兴水处理开展了一系列探究性试验。
2 研究目标与内容2.1 研究目标在运用国家标准HJ 828—2017重铬酸盐法测定COD 时,消除高氯废水对其COD 测定的结果的影响,提高测定准确度,降低成本,尽量避免二次污染。
2.2 研究内容考虑到高氯废水对测定COD 的影响,对遮蔽剂硫酸汞做1 概述随着我国工业化进程的不断发展,工业生产得到迅猛发展,高氯废水排放量也日益增加。
绍兴水处理发展有限公司(以下简称“绍兴水处理”)工业废水处理规模60万t/d ,进水以上游企业印染废水、化工废水为主。
化工废水接近1.3万t/d ,其中不乏大量高氯废水,而在对这些废水的处理中,测定化学需氧量COD 是了解水体受到有机物污染的程度,并进而消除有机污染物的重要环节之一。
目前,COD 值国家标准测定的方法是HJ 828—2017中规定的重铬酸盐法,该标准方法原理: 水样中还原性物质时所消耗氧化剂重铬酸钾的量,折算成每升水样全部被氧化后,需要的氧的毫克数。
水质化学需氧量测定全程质量控制郑昌军(雅安市雨城生态环境监测站 四川雅安 625000)摘要:在开展环境监测工作中,质量控制是必要手段,通过质量控制可提升环境监测数据的可靠性与准确性。
目前,水质化学需氧量测定采用的方法有很多种,如重铬酸盐法、高锰酸钾法以及分光光度法等。
首先对各种测定方法进行简要介绍,然后结合四川省某县域内河流的水质情况,选择适当的测定方法对该河流的水质化学需氧量进行测定,并制定测定全程质量控制方法,从而为水质化学需氧量测定的质量和效果提供保障。
关键词:水质 化学需氧量 测定方法 全程质量控制中图分类号:X832文献标识码:A 文章编号:1672-3791(2023)22-0187-04Quality Control of the Whole Process of the Chemical Oxygen Demand Determination of Water QualityZHENG Changjun(Yucheng Ecological Environment Monitoring Station, Ya'an, Sichuan Province, 625000 China) Abstract: In the development of environmental monitoring, quality control is a necessary means, and the reliability and accuracy of environmental monitoring data can be improved through quality control. At present, there are many methods used for the determination of the chemical oxygen demand of water quality, such as dichromate titration, permanganate titration and spectrophotometry. This paper first briefly introduces various determination methods, then, combined with the water quality of a river in a county in Sichuan Province, selects appropriate determination methods to determine the chemical oxygen demand of water quality in the river, and formulates the quality control method of the whole process of determination, so as to ensure the quality and effect of the chemical oxygen demand determination of water quality.Key Words: Water quality; Chemical oxygen demand; Determination method; Whole process quality control所谓化学需氧量主要是指在特定的条件下,被检测水体之中包含的还原性物质受到强氧化剂产生的氧化作用影响的情况下,所用氧化剂的使用量,通常将氧的质量浓度来对其进行表示。
化学需氧量英语Chemical Oxygen Demand (COD)The concept of Chemical Oxygen Demand (COD) is a crucial parameter in the field of environmental science and water quality management. COD is a measure of the amount of oxygen required to oxidize all the organic and inorganic matter in a water sample, both biodegradable and non-biodegradable. This measurement is essential in understanding the overall pollution load of water bodies and the subsequent treatment required to meet environmental standards.The importance of COD lies in its ability to provide a comprehensive understanding of the water's quality. Unlike the Biochemical Oxygen Demand (BOD) test, which only measures the amount of oxygen required for the biological breakdown of organic matter, COD encompasses a wider range of organic and inorganic compounds. This includes substances that are resistant to biological degradation, such as certain industrial chemicals, pesticides, and even some types of organic matter.The COD test is performed by adding a strong oxidizing agent, suchas potassium dichromate (K2Cr2O7), to a water sample. The oxidizing agent reacts with the organic and inorganic matter, converting them to carbon dioxide and water. The amount of oxygen consumed during this process is then measured and expressed as the COD value, typically in milligrams of oxygen per liter of water (mg/L).The COD test is widely used in various industries and applications, including municipal and industrial wastewater treatment, surface water quality monitoring, and groundwater assessment. In the wastewater treatment context, COD is a crucial parameter for determining the effectiveness of the treatment process and ensuring compliance with environmental regulations. By monitoring the COD levels, operators can optimize treatment strategies, ensure efficient removal of pollutants, and minimize the impact of effluent discharge on receiving water bodies.Furthermore, COD measurements are essential in the management of industrial processes, where the disposal of high-strength waste streams can have significant environmental consequences. Industries such as food processing, pulp and paper, and chemical manufacturing rely on COD analysis to assess the pollution load of their wastewater and implement appropriate treatment methods.In addition to its practical applications, COD measurement also playsa vital role in scientific research and environmental monitoring. Researchers use COD data to study the sources, transport, and fateof organic and inorganic pollutants in aquatic ecosystems, as well as to assess the overall health and resilience of these systems. This information is crucial for the development of effective environmental policies, conservation strategies, and sustainable resource management practices.Despite its widespread use, the COD test is not without its challenges. The method can be influenced by the presence of certain inorganic compounds, such as chlorides and nitrites, which can interfere with the oxidation process. Additionally, the COD test does not provide information on the specific nature of the organic compounds present, which can limit its usefulness in certain applications.To address these challenges, researchers and practitioners have developed various modifications and alternative methods for COD determination, such as the use of specific oxidizing agents, microbial-based assays, and advanced analytical techniques like gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS).In conclusion, the Chemical Oxygen Demand (COD) is a fundamental parameter in the field of water quality assessment and environmental management. It provides a comprehensive understanding of thepollution load in water bodies, enabling informed decision-making and the implementation of effective treatment strategies. As environmental concerns continue to be a global priority, the importance of COD monitoring and analysis will only increase, contributing to the sustainability and protection of our precious water resources.。
本电子版为发布稿。
请以中国环境科学出版社出版的正式标准文本为准。
HJ 中华人民共和国环境保护行业标准HJ/T 399-2007水质 化学需氧量的测定快速消解分光光度法Water quality-Determination of the chemical oxygen demand -Fast digestion-Spectrophotometric method(发布稿)2007-12-07发布 2008-03-01 实施 国家环境保护总局发 布目 次前言 (Ⅱ)1适用范围 (1)2规范性引用文件 (1)3术语和定义 (1)4原理 (1)5试剂和材料 (2)6干扰及消除 (5)7仪器和设备 (5)8样品 (7)9测定条件的选择 (7)10步骤 (8)11结果的表示 (9)12准确度和精密度 (10)前言为贯彻《中华人民共和国环境保护法》,保护环境,保障人体健康,规范国家环境污染物监测方法,制定本标准。
本标准规定了地表水、地下水、生活污水和工业废水中化学需氧量的快速消解分光光度测定方法。
本标准为首次制定。
本标准为指导性标准。
本标准由国家环境保护总局科技标准司提出。
本标准主要起草单位:河北省环境监测中心站。
本标准国家环境保护总局2007年12月7日批准。
本标准自2008年3月1日起实施。
本标准由国家环境保护总局解释。
水质 化学需氧量的测定 快速消解分光光度法警告:硫酸汞属于剧毒化学品,硫酸也具有较强的化学腐蚀性,操作时应按规定要求佩带防护器具,避免接触皮肤和衣服,若含硫酸溶液溅出,应立即用大量清水清洗;在通风柜内进行操作;检测后的残渣残液应做妥善的安全处理。
1适用范围本标准适用于地表水、地下水、生活污水和工业废水中化学需氧量(COD)的测定。
本标准对未经稀释的水样,其COD测定下限为15 mg/L,测定上限为1000mg/L,其氯离子浓度不应大于1000mg/L。
本标准对于化学需氧量(COD)大于1000mg/L或氯离子含量大于1000mg/L的水样,可经适当稀释后进行测定。
本电子版为发布稿。
请以中国环境科学出版社出版的正式标准文本为准。
HJ 中华人民共和国环境保护行业标准HJ/T 399-2007水质 化学需氧量的测定快速消解分光光度法Water quality-Determination of the chemical oxygen demand -Fast digestion-Spectrophotometric method(发布稿)2007-12-07发布 2008-03-01 实施 国家环境保护总局发 布目 次前言 (Ⅱ)1适用范围 (1)2规范性引用文件 (1)3术语和定义 (1)4原理 (1)5试剂和材料 (2)6干扰及消除 (5)7仪器和设备 (5)8样品 (7)9测定条件的选择 (7)10步骤 (8)11结果的表示 (9)12准确度和精密度 (10)前言为贯彻《中华人民共和国环境保护法》,保护环境,保障人体健康,规范国家环境污染物监测方法,制定本标准。
本标准规定了地表水、地下水、生活污水和工业废水中化学需氧量的快速消解分光光度测定方法。
本标准为首次制定。
本标准为指导性标准。
本标准由国家环境保护总局科技标准司提出。
本标准主要起草单位:河北省环境监测中心站。
本标准国家环境保护总局2007年12月7日批准。
本标准自2008年3月1日起实施。
本标准由国家环境保护总局解释。
水质 化学需氧量的测定 快速消解分光光度法警告:硫酸汞属于剧毒化学品,硫酸也具有较强的化学腐蚀性,操作时应按规定要求佩带防护器具,避免接触皮肤和衣服,若含硫酸溶液溅出,应立即用大量清水清洗;在通风柜内进行操作;检测后的残渣残液应做妥善的安全处理。
1适用范围本标准适用于地表水、地下水、生活污水和工业废水中化学需氧量(COD)的测定。
本标准对未经稀释的水样,其COD测定下限为15 mg/L,测定上限为1000mg/L,其氯离子浓度不应大于1000mg/L。
本标准对于化学需氧量(COD)大于1000mg/L或氯离子含量大于1000mg/L的水样,可经适当稀释后进行测定。