Comparative analysis of the bacterial diversity in a lab-scale moving bed bio?lm reactor (MBBR)applied to treat urban wastewater under different operational conditions
Kadiya Calderón a ,?,Jaime Martín-Pascual b ,JoséManuel Poyatos b ,Belén Rodelas a ,Alejandro González-Martínez b ,Jesús González-López a
a Department of Microbiology,University of Granada,Granada 18071,Spain b
Department of Civil Engineering,University of Granada,Granada 18071,Spain
h i g h l i g h t s
"Carrier FR is the major operational parameter on the bio?lm formation in a lab-scale MBBR."HRT and carrier type not in?uence statistically on the bacterial diversity of the bio?lm."Carrier FR is the critical parameter in the start-up of MBBR-based WWTP.
a r t i c l e i n f o Article history:
Received 4May 2012
Received in revised form 26June 2012Accepted 27June 2012
Available online 5July 2012Keywords:Bio?lm MBBR TGGE
Carrier-FR HRT
a b s t r a c t
Different types of carriers were tested as support material in a lab-scale moving bed bio?lm reactor (MBBR)used to treat urban wastewater under three different conditions of hydraulic retention time (HRT)and carrier ?lling ratios (FR).The bacterial diversity developed on the bio?lms responsible of the treatment was studied using a cultivation-independent approach based on the polymerase chain reaction-temperature gradient gel electrophoresis technique (PCR-TGGE).Cluster analysis of TGGE ?n-gerprints showed signi?cant differences of community structure dependent upon the different opera-tional conditions applied.Redundancy analysis (RDA)was used to determine the relationship between the operational conditions (type of carrier,HRT,FR)and bacterial bio?lm diversity,demonstrating a signi?cant effect of FR =50%.Phylogenetic analysis of PCR-reampli?ed and sequenced TGGE bands revealed that the prevalent Bacteria populations in the bio?lm were related to Betaproteobacteria (46%),Firmicutes (34%),Alphaproteobacteria (14%)and Gammaproteobacteria (9%).
ó2012Elsevier Ltd.All rights reserved.
1.Introduction
Urban and industrial wastewater reclamation is nowadays one of the major research topics resourced by people and governments.Untreated or insuf?ciently treated wastewater discharged to the environment causes several problems,such as eutrophication (Luostarinen et al.,2006;Plattes et al.,2007).In order to improve the quality of treated wastewater and meet the demands of environmental regulations,implementation of advanced technolo-gies for treatment is required (Trapani et al.,2010).Biological processes based on bio?lms have been proved to offer satisfactory solutions for the removal of organic components and nitrogen from wastewater,avoiding some of the problems associated with acti-vated sludge process,such as large reactor size,need for settling tanks,and biomass recycling (Luostarinen et al.,2006;McQuarrie and Boltz,2011).
Moving bed bio?lm reactors (MBBRs)have been widely applied to treat both urban and industrial wastewaters.This technology allows BOD 5and N removal rates similar to those of activated sludge-based processes,with the advantage of a smaller tank vol-ume (Andreottola et al.,2000).MBBRs can be operated as anoxic or aerobic phases with freely moving buoyant plastic bio?lm carriers.The systems include a submerged bio?lm reactor and a liquid-solid separation unit.The objective of the MBBR systems is to achieve the growth of the biomass as a bio?lm on small carriers,which have lower density than water,are continuously kept in the tank and are able to move freely in the reactor without sludge recycling (?degaard,2008).Bio?lm carriers made out of different materials and designs have been developed and are commercially accessible.
0960-8524/$-see front matter ó2012Elsevier Ltd.All rights reserved.https://www.doczj.com/doc/c715011950.html,/10.1016/j.biortech.2012.06.078
?Corresponding author.Address:Departamento de Microbiología,Facultad de Farmacia,Universidad de Granada,18071Granada,Spain.Tel.:+34958249966;fax:+34958246235.
E-mail address:kcalderona@ugr.es (K.Calderón).
Also,studies based on its mechanical and technical removal rates are available(McQuarrie and Boltz,2011).
Knowledge on the microbiota composition involved in bio?lm processes and the mechanisms by which operational variations may in?uence their structure is regarded as crucially important for the optimization of nutrient removal rates on MBBR systems and to implement control strategies(Boltz et al.,2011;Ciesielski et al.,2010).However,to date,little research is available related to the characteristics of the microbial bio?lms grown on MBBRs, in particular,information concerning their community composi-tion(McQuarrie and Boltz,2011).The aim of this work was to?nd the relationships between different operational conditions(type of carrier,carrier?lling ratio,and hydraulic retention time)and the community structure of bacterial bio?lms developed on MBBRs. For this purpose,scanning electron microscopy(SEM)and molecu-lar?ngerprinting tools such as polymerase chain reaction(PCR) coupled to temperature gradient gel electrophoresis(TGGE)were used.Identi?cation of the dominant bacteria inhabiting the bio?lm was achieved by DNA sequencing of the prevalent TGGE bands. 2.Methods
2.1.Description of the lab-scale MBBRs and operating conditions
The lab-scale plant consisted of three reactors(each one with a 3-L operating volume),operated in parallel and fed from a common feed tank by a multichannel peristaltic pump.The feed tank was ?lled periodically with water from the outlet of the primary settler from the wastewater treatment plant(WWTP)of Estación depur-adora Puente de Los Vados,(EMASAGRA,Granada,Spain).
Special sieve arrangements were adopted to retain the carriers inside the aerobic reactors.The necessary aeration system is sup-plied by a compressor,from which three lines are derived for each of the reactors.To ensure adequate air diffusion and the homoge-neity of the mixed liquor in the bioreactor,each reactor was equipped with a porous plate and a stirring system.A system for the purge of excess sludge was also provided in each reactor.Dis-solved oxygen(DO)was measured daily using an oximeter to en-sure aerobic conditions.Each of the three reactors was operated for three weeks with each of the carrier?lling ratios,in three con-secutive phases lasting7days each,with in?uent?ows of0.6,0.3 and0.2L/h,corresponding to hydraulic retention times(HRT)of 5,10and15h,respectively.Table1shows a summary of the oper-ational parameters of the reactors and the names of all the ana-lyzed samples of bio?lms corresponding to their respective HRT, FR and type of carrier.Carrier inoculation was done by recycling mixed liquor as described by Jahren et al.(2002)with hal?oad acti-vated sludge from the WWTP which had a medium concentration of suspended solids equal to3±0.27g/l.
Each reactor was?lled with a different carrier material(Aqwise ABC5in Reactor1,K1in Reactor2,and BIOCONS in Reactor3).The Aqwise ABC5and K1carriers were made from high density poly-ethylene and the BIOCONS carrier was made from polyurethane sprayed with activated carbon.Characteristics of the reactors and carriers are described in detail elsewhere(Martín-Pascual et al., 2012).The three carriers were tested at?lling ratios(FR)of50%, 35%and20%,as previously described by Martín-Pascual et al. (2012).
2.2.Scanning electron microscopy analysis
The small pieces of carrier material with adhered bio?lm were sampled from the reactors to observe and analyze the structure of the bio?lm with a LEO1430-VP SEM,coupled to an Oxford ISIS 400EDX system.The samples were?xed,dehydrated and gold-coated as previously described by Calderón et al.(2011).
2.3.DNA extraction and PCR ampli?cation of partial bacterial16S rRNA genes
DNA was extracted from bio?lms sampled from the three biore-actors operated under all the tested conditions.A volume of ca. 60ml of bio?lm-colonized carriers were collected from the biore-actors with a sieve sampling device,in order to separate the carri-ers from the mixed liquor.The collected carriers were placed in sterile containers,added with20ml of sterile saline solution and vortexed for1min.The suspended bio?lm material was collected by centrifugation at3000g for10min.DNA was immediately ex-tracted from the bio?lm samples(ca.200mg),using the FastDNA Spin Kit for Soil and the FastPrep24apparatus(MP-BIO,Germany).
Two-step approaches were used for PCR ampli?cation,as previ-ously described by other authors for TGGE or DGGE?ngerprinting (Calderón et al.,2011;Molina-Mu?oz et al.,2009).Reaction mix-tures(50l l?nal volume)contained1?Gold PCR buffer (150mM Tris–HCl,pH8.0,500mM KCl,Applied Biosystems,Life Technologies,Carlsbad,CA,USA),1.5mM MgCl2(Applied Biosys-tems,Life Technologies,Carlsbad,CA,USA),5%dimethylsulfoxide (Sigma-Aldrich,St.Louis,MO,USA),200l M of dNTPs(Roche Molecular Biochemicals,Germany),20pM of each primer,1U of AmpliTaq Gold polymerase(Applied Biosystems,Life Technologies, Carlsbad,CA,USA),and100l g bovine serum albumine(New Eng-land Biolabs,UK).One microliter of the DNA extracted(5ng)was used as a template.HPLC-puri?ed oligonucleotides were pur-chased from Sigma(St.Louis,MO,USA),and were used for all PCRs, performed in an Eppendorf Master Cycler(Eppendorf,Hamburg, Germany).The temperature pro?le for the?rst PCR reaction was as follows:initial denaturation at95°C for7min;25cycles of denaturation at94°C for1min10s,annealing at56°C for40s, extension at72°C for2min;and?nal extension at72°C for 6min10s.A modi?ed form of the touchdown thermal pro?le tech-nique(Calderón et al.,2011)was used for the second PCR;this technique involved7min of activation of the polymerase at94°C before two cycles consisting of1min at94°C,1min at65°C, and2min at72°C.The annealing temperature was subsequently decreased by1°C for every second cycle until it reached55°C,at which point10additional cycles were carried out;?nally,a10-min extension step at72°C was performed.The?nal PCR products were cleaned and concentrated using Amicon Ultra-0.5mL Centrif-ugal Filters(Eppendorf,Hamburg,Germany).80–100ng of DNA were loaded into each well for TGGE.
2.4.TGGE
The denaturing gels(6%polyacrylamide(37.5:1acrylamide:bis-acrylamide),20%deionized formamide,2%glycerol and8M urea) were made and run with a2?Tris–acetate–EDTA buffer.TGGE was performed using a TGGE Maxi system(Whatman-Biometra, Goettingen,Germany).All chemicals required were purchased from Sigma Aldrich(St.Louis,MO,USA).The temperature gradient was43–63°C,as previously optimized by Molina-Mu?oz et al. (2009).Gels were run at125V for18h.The bands were made vis-ible with silver staining using the Gel Code Silver Staining kit (Pierce,Thermo Fisher Scienti?c,Rockford,IL,USA)(Calderón et al.,2012).Different PCR reactions were tested and different TGGE gels were run to check the reproducibility of the results.
2.5.Fingerprint analysis
The band patterns generated by TGGE were normalized, compared and clustered using the Gel Compar II v.5.101software
120K.Calderón et al./Bioresource Technology121(2012)119–126
(Applied Maths,Belgium).Cluster analyses of the TGGE pro?les were done using a band assignment independent method(Pearson product–moment correlation coef?cient).A method based on band presence/absence(Dice coef?cient)was also used and compared. For band assignment,a1%band position tolerance(relative to the total length of the gel)was applied(Calderón et al.,2011). The dendrograms relating band pattern similarities were automat-ically calculated with the unweighted pair group method with arithmetic mean algorithm(UPGMA).The signi?cance of UPGMA clustering was estimated by calculating the cophenetic correlation coef?cients.Based on the TGGE?ngerprints,the Shannon–Wiener index of diversity,H’(Shannon and Weaver,1963),was calculated for each TGGE lane using the function:
H’?à
X S
i?1
pi ln pi
where S represents the total number of bands in a given TGGE lane, and pi represents the relative intensity of a given band in the whole densitometric curve of the corresponding lane.Relative intensities of bands were calculated using Gel Compar II(Calderón et al.,2012).
The calculation of the Fo index,which allows for the evaluation of the functional redundancy of the microbial communities ana-lyzed by?ngerprinting methods(Marzorati et al.,2008),was done as previously described(Calderón et al.,2012).
2.6.DNA reampli?cation and sequencing
As a result of TGGE pro?les,portions of silver-stained individual bands were picked up with sterile pipette tips and placed in10l L of?ltered and autoclaved water.Three microlitre of the resulting DNA suspensions were used to re-amplify the separated bands using the appropriate primers.The PCR products were electropho-resed in agarose gels to be checked,and puri?ed with the Qiaex-II kit(Qiagen,Hamburg,Germany).The recovered DNA was directly used for automated sequencing in an ABI PRISM3100Avant Genet-ic Analyzer(Life Technologies,CA,USA).2.7.Phylogenetic analysis
The DNA sequences were analyzed and compared using the biocomputing tools provided online by the National Center for Biotechnology Information(https://www.doczj.com/doc/c715011950.html,).The BLASTn program(Altschul et al.,1997)was used for sequence sim-ilarity analysis.The ClustalX v.2.0.3software(Jeanmougin et al., 1998)was used for the alignment of the DNA sequences.Phyloge-netic and molecular evolutionary analyses were conducted using MEGA version4(Tamura et al.,2007).A p-distance based evolu-tionary tree was inferred using the Neighbor-Joining algorithm. The bootstrap test was conducted to infer the reliability of branch order,with a round of1000reassemblings.Bootstrap values below 50%are not shown in the tree.
2.8.Statistical analysis
To calculate the analyses of variance(ANOVA),STATGRAPHICS 5.0(STSC,Rockville,MD,USA)was used.A signi?cance level of 95%(p<0.05)was selected.
Redundancy analysis(RDA),an ordination method of direct gra-dient analysis(Lep?and?milauer,1999),was performed to search for patterns in the set of operational conditions(HRT,FR,and type of carrier)and to assess their relationship with the composition of the bacterial communities developed on the different carriers. TGGE banding patterns generated by Gel Compar II were converted to a binary matrix by scoring bands(=species)as present(1)or ab-sent(0),and this matrix was used for RDA without transformation. RDA was chosen as the ordination method after initial analysis by detrended correspondence analysis(DCA)revealed that the opera-tional parameters data exhibited a linear,rather than unimodal, response to the bacterial community(Lep?and?milauer,1999). The Monte Carlo permutation test was used to assess the statistical signi?cance of the canonical axes.All the multivariate statistics were computed using the Canoco for Windows v.4.5software (ScientiaPro,Budapest,Hungary).
Table1
Summary of operational parameters in the reactors used in the study,and names given to samples of bio?lms used for the?ngerprinting studies.FR:?lling ratio;HRT:hydraulic retention time;sCOD,soluble chemical oxygen demand;MLSSt:total suspended solids;MLSSv:volatile suspended solids.
Carrier type Carrier FR(%)HRT(h)sCOD in?uent(mg O2/l)sCOD removed(%)MLSS t(mg/l)MLSS v(mg/l)Sample name
AQWISE ABC5205146±1628.52±5.192033±841855±10616
10137±3034.54±5.102019±881848±10215
15116±2840.40±8.082052±1031907±989 35599±2339.36±7.462026±701840±8422
10133±1948.71±9.282005±1181901±12725
15128±1750.20±5.781903±791724±8417 505129±4240.49±7.132101±1161890±18518
10140±4050.37±9.112081±701900±892
15166±3256.97±5.951918±1471769±1486 K1205146±1629.83±3.792110±371995±5513
10137±3030.06±7.161952±1001808±10410
15116±2843.21±4.652070±1201981±14819 35599±2338.87±6.262130±1012011±10923
10133±1950.13±4.262105±1271948±18726
15128±1753.37±4.251987±1091804±12620 505129±4239.92±6.922216±1262026±1774
10140±4057.25±8.382177±1171984±1173
15166±3258.92±7.382069±2131938±2047 BIOCONS205146±16 5.38±0.962138±732048±7214
10137±3016.28±5.582067±941992±10312
15116±2825.50±4.432129±1082047±10911 35599±2310.66±2.112067±451986±5624
10133±1924.50±10.772057±1331966±12927
15128±1732.60±5.281975±641887±6221 505129±4224.57±9.672037±481935±435
10140±4043.24±5.252014±691937±721
15166±3246.13±4.892021±511935±508
K.Calderón et al./Bioresource Technology121(2012)119–126121
3.Results and discussion
3.1.Analysis of bio?lm communities by SEM and EDX
SEM images of the three carrier types with and without bio?lms developed on their surfaces are shown in Figs.S1–S3(supplemen-tary material).Bio?lms formed on the three different carriers when the reactors were operated at an HRT of5h are shown in Fig.S1. Some differences in the structure of the bio?lms were visible,as a more mature bio?lm and better colonized carrier surface were observable for50%FR,compared to35%and20%FR(Fig.S1).Dif-ferent microorganisms of diverse morphologies were observed, including rod-shaped and?lamentous cells(Fig.S2).The EDX anal-ysis detected only organic material and no inorganic deposits were
type of carrier or the HRT.Cluster analysis based on the Dice coef-?cient showed equivalent results to the Pearson-based clustering.
A total of93band classes were detected.Band classes A,B,C,D,E, F,G and H were present in all samples(Fig.1).
The average values of the Shannon index(H’)calculated for the different bacterial communities developed under all the operation conditions tested were compared by ANOVA analysis,showing that the only parameter that displayed a signi?cant in?uence(p<0.01) on bacterial diversity was the carrier?lling ratio(FR)(Table2A). The Student’s T test showed that the bio?lms developed in the reactors operated at50%FR had a signi?cantly higher value of H’, indicative of a higher bacterial diversity(Table2B).
The signi?cant in?uence of FR on the diversity of the bio?lm bacterial community was also con?rmed by RDA,based on TGGE
122K.Calderón et al./Bioresource Technology121(2012)119–126
values of the Fo indices calculated for the bio?lms formed on each of the reactors,under any operation conditions tested.From the average values of Fo obtained(16±2%),it could be inferred that the bacterial communities for each reactor had high evenness.In ecological terms,these communities may result from a lack of selective pressure and do not present a well-de?ned internal struc-ture with regards to species dominance.Therefore,the communi-ties are assumed to have an‘on average’low functional organization(Marzorati et al.,2008).
Research devoted to the biology of MBBR systems has increased in the last years.Several studies compare the in?uence of different type of carriers,based on the material,shape and size,on the re-moval of C and N by bacterial communities in these systems (Chu and Wang,2011;Gong et al.,2011;Levstek and Platz, 2009).Regarding the study of the bio?lm community composition and diversity,available previous work was speci?cally aimed at analyzing the nitrifying communities(Bernet et al.,2004),as MBBR systems are particularly ef?cient for the elimination of nitrogen compounds(?degaard,2006).
The results of the present study pointed out that the carrier?ll-ing ratio is the major parameter in?uencing the bacterial commu-nity structure,while signi?cant differences due to the type of carrier tested were not observed,under the conditions of the study. Carrier?lling ratio was previously reported as an important parameter in?uencing the performance of MBBR systems.In this sense,Wang et al.(2005)evaluated the in?uence of different car-rier?lling ratios(10–75%)on the pollutant removal rates,biomass and bio?lm activity of a MBBR,using a polyvinyl chloride carrier and synthetic wastewater.These authors demonstrated that COD removal rates increased for carrier?lling ratios10–50%,but did not improve over this value.Similar results were obtained by Mar-tín-Pascual et al.(2011),with higher COD removal rates in reactors that worked with50%FR,regardless of the carrier type tested.
Wang et al.(2005)reported that differences in the morphology and composition of bio?lms were observable by SEM analysis when the carrier concentration was changed in the reactor.These differences were explained by the higher overall amount of bio-mass and the restricted movement of the carriers in the bioreactor at higher carrier?lling ratios,which increases collisions and abra-sion forces among the carrier particles,leading to the selection of the bacteria able to grow on the carrier under these conditions (Martín-Pascual et al.,2012;Wang et al.,2005).As the carrier con-centration increases,the total surface area of carrier increases accordingly and more positions are available for bacteria to attach. However,when the FR is more than the50%,the shear stresses on bio?lm becomes greater and detachment of the bio?lm enhanced (Gjaltema et al.,1995).
Bacterial communities in MBBRs or analogous moving bed bio-?lm systems have seldom been monitored by molecular methods, but available data also demonstrates that different concentrations of carrier material in?uence community composition of the bio-?lms.Bernet et al.(2004)analyzed the nitrifying communities of inverse turbulent bed reactors by single strand conformation poly-morphism(SSCP)targeting PCR-ampli?ed partial16S rRNA genes, comparing10%and30%FR in separated reactors and concluding that the bio?lms formed under a30%FR showed higher diversity of nitrifying bacteria,in correspondence to higher ratios of nitro-gen removal.
3.2.2.Phylogenetic study of the DNA sequences of the prevalent TGGE bands
A total of35TGGE bands were successfully reampli?ed and se-quenced from TGGE gels,corresponding to the dominant popula-tions in the bio?lms communities and representing60%of the total band classes recognized.All the partial16S-rRNA gene se-quences were deposited on the European Nucleotide Archive (EMBL/ENA)with the accession numbers HE863673–HE863707.
A prevalence of Proteobacteria in the set of sequences analyzed was found for all stages.The main group of identi?able TGGE bands was related to Betaproteobacteria(15of35sequences,43%) (Fig.3).The second group in order of abundance was Firmicutes
Table2
Effect of the operational parameters(carrier type,hydraulic
retention time and carrier?lling ratio)on the Shannon’s diversity
index(H’)of the bio?lm communities developed in the MBBR.(A)
Results of ANOVA analysis.(B)Results of the Student’s t test for
carrier?lling ratio.LSD:least signi?cant difference(p<0.05).
Fig.2.Redundancy analysis(RDA)ordination diagram(biplot)showing samples
(numbered circles)and operational parameters(black triangles)during operation
the MBBR under all conditions tested.First axis is horizontal,second axis is vertical.
HRT5,HRT10,HRT15:hydraulic retention times of5,10and15h,respectively;AQ,
K1,BC,carriers AQWISE ABC5,K1and BIOCONS,respectively;FR20,FR35,FR50,
carrier?lling ratios of20%,35%and50%,respectively.
K.Calderón et al./Bioresource Technology121(2012)119–126123
phylogenetic tree showing the positions of35bacteria sequences from re-ampli?ed TGGE bands and the most similar sequences on ca.200nt length of sequences.The scale bar indicates a1%divergence.Bootstrap values over50%are shown in nodes.
also support the universal prevalence of Proteobacteria in WWTPs (Xia et al.,2010;Ye et al.,2011).Little is known about the compo-sition of the bio?lm bacterial communities in MBBR systems.Ber-net et al.(2004)detailed the composition of nitrifying bacteria in bio?lm reactors fed with synthetic mineral wastewater containing a high ammonium concentration,demonstrating that Nitrosomonas sp.and Nitrospira played an important role in the removal of nitro-gen from these systems,as also reported for most wastewater treatment technologies(Wagner and Loy,2002).
Interestingly,the results of the community analysis described here showed that34%of the TGGE bands identi?ed by DNA sequencing were related to the genus https://www.doczj.com/doc/c715011950.html,ctobacilli are obligate fermentative bacteria,however,they are often abun-dant in bio?lms from aerobic wastewater treatment systems (Eusébio et al.,2011;Soondong et al.2010).Anaerobic and micro-aerophilic bacteria inhabit complex bio?lms exposed to air due to the depletion of the oxygen levels as the bio?lm depth increases, which creates anoxic zones(Santegoeds et al.,1998).A large num-ber of populations related to the genus Lactobacillus in wastewater is often linked to the presence of lactose sugar,a common feature of wastewaters originating from the food industry(Acharya et al., 2011).In this sense,the wastewater used in the study was taken from the primary settling tank of an urban wastewater facility, which receives ef?uents from a local dairy industry(Poyatos et al.,2007).
4.Conclusions
MBBR-systems are becoming widespread for wastewater treat-ment,and studies regarding the impact of operation conditions on bacterial community composition and performance are gaining importance in the improvement of reactor design and optimiza-tion.The presented results show that carrier FR is the major oper-ational factor in?uencing the bacterial community structure of the bio?lms in a lab-scale urban WWTP.These results are in accor-dance with previous work linking carrier FR to MBBR performance in terms of biological removal of COD and nitrogen.Hence,avail-able data point to the optimization of carrier FR as a critical step in the start-up of MBBR-based WWTPs.
Acknowledgements
This research was supported by the Spanish Ministerio de Cien-cia y Tecnología(MCyT,Spain,project reference CTM2009-11929-C02-01and CTM2009-11929-C02-02,and a personal grant(FEU–University of Granada)to K.Calderón.The Instituto de Parasit-ología y Biología Molecular López Neyra(CSIC,Granada,Spain) needs to be acknowledged for their DNA sequencing service.Isabel Guerra from Centro de Instrumentación Cientí?ca(UGR,Granada Spain)needs to be also acknowledged for the SEM support offered. The authors also wish to thank Dennis Hubbard for kindly revising the English language content.
Appendix A.Supplementary data
Supplementary data associated with this article can be found, in the online version,at https://www.doczj.com/doc/c715011950.html,/10.1016/j.biortech. 2012.06.078.
References
Acharya,B.K.,Pathak,H.,Mohana,S.,Shouche,Y.,Singh,V.,Madamwar,D.,2011.
Kinetic modeling and microbial community assessment of anaerobic biphasic ?xed?lm bioreactor treating distillery spent wash.Water Res.14,4248–4259. Altschul,S.F.,Madden,T.L.,Schaffer,A.A.,Zhang,J.H.,Zhang,Z.,Miller,W.,Lipman,
D.J.,1997.Gapped BLAST and PSI-BLAST:a new generation of protein database
search programs.Nucleic Acids Res.25,3389–3402.Andreottola,G.,Foladori,P.,Ragazzi,M.,Tatàno,F.,2000.Experimental comparison between MBBR and activated sludge system for the treatment of municipal wastewater.Water Sci.Technol.41,375–382.
Bernet,N.,Sánchez,O.,Dabert,P.,Ola?zola,A.,Godon,J.J.,Delgenès,J.P.,2004.Effect of solid hold-up on nitrite accumulation in a bio?lm reactor-molecular characterization of nitrifying communities.Water Sci.Technol.49,123–130. Boltz,J.P.,Morgenroth,E.,Brockmann,D.,Bott,C.,Gellner,W.J.,Vanrolleghem,P.A., 2011.Systematic evaluation of bio?lm models for engineering practice: components and critical assumptions.Water Sci.Technol.64,930–944. Calderón,K.,Rodelas,B.,Cabirol,N.,González-López,J.,Noyola,A.,2011.Analysis of microbial communities developed on the fouling layers of a membrane-coupled anaerobic bioreactor applied to wastewater treatment.Bioresour.Technol.102, 4618–4627.
Calderón,K.,González-Martínez, A.,Montero-Puente, C.,Reboleiro-Rivas,P., Poyatos,J.M.,Juárez-Jiménez, B.,Martínez-Toledo,M.V.,Rodelas, B.,2012.
Bacterial community structure and enzyme activities in a membrane bioreactor (MBR)using pure oxygen as an aeration source.Bioresour.Technol.103,87–94. Chu,L.,Wang,J.,https://www.doczj.com/doc/c715011950.html,parison of polyurethane foam and biodegradable polymer as carriers in moving bed bio?lm reactor for treating wastewater with
a low C/N ratio.Chemosphere83,63–68.
Ciesielski,S.,Kulikowska,D.,Kaczowka,E.,Kowal,P.,2010.Characterization of bacterial structures in two-stage moving-bed bio?lm reactor(MBBR)during nitri?cation of the land?ll leachate.J.Microbiol.Biotechnol.20,1140–1151. Eusébio,A.,Tac?o,M.,Chaves,S.,Tenreiro,R.,Almeida-Vara,E.,2011.Molecular assessment of microbiota structure and dynamics along mixed olive oil and winery wastewaters biotreatment.Biodegradation22,773–795.
Gjaltema,A.,Tijhuis,L.,van Loosdrecht,M.C.M.,Heijnen,J.J.,1995.Detachment of biomass from suspended nongrowing spherical bio?lms on airlifted reactors.
Biotechnol.Bioeng.46,258–269.
Gong,W.J.,Liang,H.,Li,W.Z.,Wang,Z.Z.,2011.Selection and evaluation of bio?lm carrier in anaerobic digestion treatment of cattle manure.Energy36,3572–3578.
Jahren,S.J.,Rintala,J.A.,Odegaard,H.,2002.Aerobic moving bed bio?lm reactor treating thermomechanical pulping whitewater under thermophilic conditions.
Water Res.36,1067–1075.
Jeanmougin,F.,Thompson,J.D.,Gouy,M.,Higgins,D.G.,Gibson,T.J.,1998.Multiple sequence alignment with Clustal X.Trends.Biochem.Sci.23,403–405.
Lep?,J.,?milauer,P.,1999.Multivariate analysis of ecological data.University of South Bohemia,CeskéBudejovice,Faculty of Biological Sciences.
Levstek,M.,Platz,I.,2009.In?uence of carrier type on nitri?cation in the moving-bed bio?lm process.Water Sci.Technol.59,875–882.
Luostarinen,S.,Luste,S.,Valentín,L.,Rintala,J.,2006.Nitrogen removal from on-site treated anaerobic ef?uents using intermittently aerated moving bed bio?lm reactors at low temperature.Water Res.40,1607–1615.
Martín-Pascual,J.,López-López, C.,Cerdá, A.,González-López,J.,Hontoria, E., Poyatos,J.M.,https://www.doczj.com/doc/c715011950.html,parative kinetic study of carrier type in a moving bed system applied to organic matter removal in urban wastewater treatment.
Water Air Soil Pollut222,1699–1712.
Marzorati,M.,Wittebolle,L.,Boon,N.,Daffonchio,D.,Verstraete,W.,2008.How to get more out of molecular?ngerprints,practical tools for microbial ecology.
Environ.Microbiol.10,1571–1581.
McQuarrie,J.P.,Boltz,J.P.,2011.Moving bed bio?lm reactor technology:process applications,design,and performance.Water Environ.Res.83,560–575. Molina-Mu?oz,M.,Poyatos,J.M.,Sánchez-Peinado,M.M.,Hontoria,E.,González-López,J.,Rodelas,B.,2009.Microbial community structure and dynamics in a pilot-scale submerged membrane bioreactor aerobically treating domestic wastewater under real operation conditions.Sci.Total Environ.407,3994–4003.
?degaard,H.,2006.Innovations in wastewater treatment:the moving bed bio?lm process.Water Sci.Techol.5,17–33.
?degaard,H.,2008.The use of the Moving Bed Bio?lm Reactor(MBBR)Technology for Industrial wastewater treatment.In:Proceedings of the IWA Specialized Conference On Industrial Water Treatment Systems,Amsterdam,Netherlands, Oct2–3.International Water Association:London,United Kingdom.
Plattes,M.,Fiorelli, D.,Gillé,S.,Girard, C.,Henry, E.,Minette, F.,O’Nagy,O., Schosseler,P.M.,2007.Modelling and dynamic simulation of a pilot-scale moving bed bioreactor for the treatment of municipal wastewater:model concepts and the use of respirometry for the estimation of kinetic parameters.
Water Sci.Technol.55,309–316.
Poyatos,J.M.,Molina-Mu?oz,M.,Moreno,B.,González-López,J.,Hontoria,E.,2007.
Effect of the mixed liquor suspended solid on permeate in a membrane bioreactor system applied for the treatment of sewage mixed with wastewater of the milk from the dairy industry.J.Environ.Sci.Health A Tox.Hazard Subst.
Environ.Eng.42,1005–1012.
Rosenberger,S.,Witzig,R.,Manz,W.,Szewzyk,U.,Kraume,M.,2000.Operation of different membrane bioreactors:experimental results and physiological state of the micro-organisms.Water Sci.Technol.41,269–277.
Santegoeds,C.M.,Muyzer,G.,de Beer,D.,1998.Bio?lm dynamics studied with microsensors and molecular techniques.Water Sci.Technol.37,125–129. Shannon,C.E.,Weaver,W.,1963.The Mathematical Theory of Communication.
University of Illinois Press,Urbana,IL.
Soondong,K.,Kim,T.S.,Yu,G.H.,Jung,J.H.,Park,H.D.,2010.Bacterial community composition and diversity of a full-scale integrated?xed-?lm activated sludge system as investigated by pyrosequencing.J.Microbiol.Biotechnol.20,1717–1723. Tamura,K.,Dudley,J.,Nei,M.,Kumar,S.,2007.MEGA4:Molecular Evolutionary Genetics Analysis(MEGA)software version4.0.Mol.Biol.Evol.24,1596–1599.
K.Calderón et al./Bioresource Technology121(2012)119–126125
Trapani, D.D.,Mannina,G.,Torregrossa,M.,Viviani,G.,2010.Quanti?cation of kinetic parameters for heterotrophic bacteria via respirometry in a hybrid reactor.Water Sci.Technol.61,1757–1766.
Wagner,M.,Loy,A.,2002.Bacterial community composition and function in sewage treatment systems.Curr.Opin.Biotechnol.13,218–227.
Wang,R.C.,Wen,X.H.,Qian,Y.,2005.In?uence of carrier concentration on the performance and microbial characteristics of a suspended carrier bio?lm reactor.Process.Biochem.40,2992–3001.Xia,S.,Duan,L.,Song,Y.,Piceno,Y.M.,Andersen,G.L.,Alvarez-Cohen,L.,Moreno-Andrade,I.,Huang, C.L.,Hermanowicz,S.W.,2010.Bacterial community structure in geographycally distributed biological wastewater treatment reactors.Environ.Sci.Tech.44,7391–7396.
Ye,L.,Shao,M.F.,Zhang,T.,Yan,S.,Tong,A.H.,Lok,S.,2011.Analysis of the bacterial community in a laboratory-scale nitri?cation reactor and a wastewater treatment plant by454-pyrosequencing.Water Res.45,4390–4398.
126K.Calderón et al./Bioresource Technology121(2012)119–126
SAF好氧生物反应池（碳氧化及硝化滤池） 目前，污水处理的主要方法有活性污泥法、生物膜法等。 生物膜法属于好氧生物处理法，是与活性污泥法一同发展起来的污水处理技术。其主要机理是微生物附着生长在一定介质的表面，形成一层生物膜，生物膜较大的表面积能够有效吸附废水中的污染物，并且具有较强的氧化能力。 生物膜法与活性污泥法的不同之处在于：活性污泥法依靠曝气池中呈悬浮状态的活性污泥来对污染物进行去除，而生物膜法是污水中的污染物转移到生物膜上，从而得到降解净化；活性污泥法是水体自净的人工强化，而生物膜法是土壤自净的人工强化。 生物膜法污水处理工艺通常由混凝土结构或钢结构的池体、池体中的填料介质、气水分布系统及反冲洗系统组成。 生物膜法水处理工艺的特点在于： ?具有很高的生物浓度，生物量是常规活性污泥的5-10倍； ?不存在污泥膨胀的问题，工艺运行稳定，操作简单，管理 方便，出水水质优而且稳定，更适用于出水水质要求高的场 合； ?微生物不会流失，有极强的水力及有机负荷抗冲击能力， 抗生物毒素及重金属能力强，更适合工业废水及含工业废水 的市政污水的处理； ?生物膜在种属上呈现多样性，生物世代期长，具有高度的 碳氧化和硝化的能力，污水氨氮处理效率极高； ?污泥产率低，节省污泥处理费用； ?占地节省。 ◆SAF工艺介绍 SAF(Submerged Aerated Filter）好氧生物反应池为升流式好氧
固定床生物膜反应器，是在曝气生物滤池(biological aerated filter，BAF)基础上发展出来的一种新型生物膜法处理工艺，其池体构造形式如下图所示，既可以作为碳氧化和硝化合二为一的高效好氧生物处理池，也可根据原水特性单独用作碳氧化池或生物硝化池。 SAF与传统滤池工艺相比有诸多改进，性能好、更节能、无堵塞、更安全。生物介质采用大粒径表面粗糙、坚固耐用的鹅卵石和蜂窝高孔、亲水、耐用的火山岩等组合填料，生物床体深，生物量大，生物挂膜均匀、活性强。各种微生物按其生存特性，按底物顺水流方向沿程分布，微生物在种属上呈现多样性，可以形成小型生态系统，有机物去除效率高，出水氨氮可达到1mg/l以下。 SAF采用渠式矩阵多点布水，布气采用穿孔管，通过专利W形气水混合滤技术，进行面源强制式布气配水，核心解决了淹没式曝气生物滤池滤柄滤头易堵的通病，整个池面布气配水十分均匀，无盲区、无死角，布气效果远优于常规单一穿孔管曝气及点源曝气头曝气，有效避免了常规滤池布气配水不均匀、滤料易板结、易出现水力短路、维护复杂等问题。 正在运行中的SAF好氧生物滤池
固定床反应器 定义：气体流经固定不动的催化剂床层进行催化反应的装置。 特点：结构简单、操作稳定、便于控制、易实现大型化和连续化生产等优点，是现代化工和反应中应用很广泛的反应器。 应用：主要用于气固相催化反应。 基本形式：轴向绝热式、径向绝热式、列管式。 固定床反应器缺点： 床层温度分布不均匀； 床层导热性较差； 对放热量大的反应，应增大换热面积，及时移走反应热，但这会减少有效空间。 流化床反应器（沸腾床反应器） 定义：流体（气体或液体）以较高流速通过床层，带动床内固体颗粒运动，使之悬浮在流动的主体流中进行反应，具有类似流体流动的一些特性的装置。 应用：应用广泛，催化或非催化的气—固、液—固和气—液—固反应。 原理：固体颗粒被流体吹起呈悬浮状态，可作上下左右剧烈运动和翻动，好象是液体沸腾一样，故流化床反应器又称沸腾床反应器。 结构：壳体、气体分布装置、换热装置、气—固分离装置、内构件以及催化剂加入和卸出装置等组成。 优点：传热面积大、传热系数高、传热效果好。进料、出料、废渣排放用气流输送，易于实现自动化生产。 缺点：物料返混大，粒子磨损严重；要有回收和集尘装置；内构件复杂；操作要求高等。 固定床： 一、固定床反应器的优缺点 凡是流体通过不动的固体物料形成的床层面进行反应的设备都称为固定床反应器，而其中尤以利用气态的反应物料，通过由固体催化剂所构成的床层进行反应的气固相催化反应器在化工生产中应用最为广泛。气固相固定床反应器的优点较多，主要表现在以下几个方面： 1、在生产操作中，除床层极薄和气体流速很低的特殊情况外，床层内气体的流动皆可看成是理想置换流动，因此在化学反应速度较快，在完成同样生产能力时，所需要的催化剂用量和反应器体积较小。 2、气体停留时间可以严格控制，温度分布可以调节，因而有利于提高化学反应的转化率和选择性。 3、催化剂不易磨损，可以较长时间连续使用。 4、适宜于高温高压条件下操作。 由于固体催化剂在床层中静止不动，相应地产生一些缺点： 1、催化剂载体往往导热性不良，气体流速受压降限制又不能太大，则造成床层中传热性能较差，也给温度控制带来困难。对于放热反应，在换热式反应器的入口处，因为反应物浓度较高，反应速度较快，放出的热量往往来不及移走，而使
流动床TM生物膜反应器( MBBR TM)工艺及在市政污水处理中的应用Moving Bed TM Biofilm Reactor (MBBR TM) Process and its Application in Municipal Wastewater Treatment 1廖足良(Zuliang Liao) AnoxKaldnes AS，P. O. Box 2011, 3103 T?nsberg Norway挪威 2喻培洁(Pia Welander) AnoxKaldnes AB，22647 Lund Sweden瑞典Hallvard ?degaard (哈尔瓦˙欧德格) 挪威科技大学水与环境工程系，7491 Trondheim Norway 挪威 摘要 流动床TM生物膜反应器(MBBR TM)工艺基于生物膜工艺的基本原理，又利用活性污泥工艺中生物量悬浮生长的特性。本文试图总结该工艺的主要特点和优势，总结该工艺在市政污水处理中去除有机物和脱氮除磷方面的研究和工程应用。 1 简介 生物膜广泛存在于自然界和人类活动中。例如，自然界中，土壤中的微生物吸附在土壤颗粒表面，形成生物膜，当从土壤的空隙流过的水中污染物(或基质)与土壤表面的生物膜接触，污染物被生物降解，因而污水被净化。生物膜一般具有很长的固体停留时间(SRT)。这有利于在不断的液流流过和基质利用过程中形成较为致密又布满孔隙的生物膜的微型空间结构。尽管生物膜的致密程度由于各方面因素(液流流速，基质浓度，供氧状态等)不同而异，其共同的非整形(FRACTAL)结构特征已被广泛认同。非整形的空隙孔径分布使得不同颗粒粒径的污染物(基质)都能够被生物膜通过不同的途经被捕获和生物降解。生物分解的产物也通过空隙传输到生物膜以外，进入水流中。当生物膜厚度达到基质难以进入最内层时，营养不足将导致生物膜本身被内源分解。这样，生物膜的厚度将随其生长的外部条件的变化而变化，并处于动态平衡。由于单位体积的生物膜量很大，生物反应器容积则可以很小，达到高效紧凑的工艺流程目标。 然而，在自然界的生物膜和固定式生物膜反应器中，被处理的污染物不很容易扩散到生物膜的内部，在好氧状态，氧分子也不很容易均匀扩散到生物膜内。同时，老化的生物膜和生物降解产物也不易于传送到生物膜外。这样，固定式生物膜反应器在理论上的优越性并没有得到充分的发挥。加上采用的挂膜材料(生物填料)可能易于变形和垮塌，使固定式生物膜反应器的应用受到很大的影响。 生物流化床工艺利用流化的颗粒填料，很好地解决了脱落的生物膜堵塞反应器的问题。流化床中采用的填料是颗粒填料，如砂，或其他人工烧结的以黏土为骨料的轻质填料。粒径小的颗粒填料虽易于流化，也易于被水流带走，颗粒大的填料不易于流化，需要很高的流化速度。为使填料保留在反应器中，适当的结构措施(如斜板)是必要的。为达到流化的目的，流化床反应器的结构设计必然较为复杂。当流化速度大时，生物膜不易于附着在颗粒填料表面，所以，颗粒填料的巨大表面积并没有得到充分利用。多孔型轻质填料虽然使有效表面积增加，但并不能根本改变这一局面。此外，当采用好氧生物流化床时，曝气充氧不易于与流化过程结合起来。 活性污泥法在二十世纪初应用于污水处理以来得到很大的发展，主要是由于其系统相对简单，处理效果在系统运行稳定情况下比较好。但长期以来，活性污泥经受负荷冲击，温度变化(特别是低温)，毒性影响，污泥膨胀的脆弱性困扰。污泥流失和系统效率低下是许多污水处理厂经常面对的问题。 一种能结合生物膜法的较高的污泥浓度，长泥龄和不需污泥回流，以及活性污泥法的无堵塞和配水及混合均匀的特点的生物处理工艺将使生物处理变得高效，稳定，和容易维护管理。流动床TM生物膜反应器(MBBR TM)工艺很好地反映了这样的要求。由AnoxKaldnes集团完成的采用MBBR TM工艺的市政和工业污水处理项目已达350多个，广泛应用于包括中国在内的全球43个国家。 2 流动床TM生物膜反应器工艺的基本原理和工艺特点
环保工程师考点：生物移动床 2017环保工程师考点：生物移动床 生物移动床也称为移动床生物膜反应器(MBP)是近年来在生物接 触氧化法和生物流化床的基础上开发的一种新型高效的生物膜法废 水处理装置。下面是关于生物移动床的知识点 作用 它既具有传统生物膜法耐冲击负荷、泥龄长和剩余污泥量少的特点，又具有活性污泥法的高效和运转灵活的特点，它是为解决固定 床生物反应器需定期反冲洗、流化床需使载体流化、淹没式生物滤 池易堵塞需清洗滤料和更换曝气头的.复杂操作而发展起来的，适合 于中小型生活污水和工业有机废水的处理。 ⑴基本工艺流程 污水经过初沉池处理后，进入生物移动床反应器，处理后的水，从反应器上方设有格栅网的溢流口流出，进入二沉池进行泥水分离。 ⑵生物移动床反应器的组成 生物移动床反应器主要由池体、载体、出水装置、曝气系统或搅拌系统等组成。 ①池体 由钢制或钢筋混凝土制成，形状为圆形或长方形等。在应用中可以利用现有活性污泥的池体或其他废弃池体改建，因此该工艺比较 适用于污水厂的改造。 ②载体(填料)
载体的密度略小于1，这些漂浮的载体随反应器内混合液的回旋翻转作用而自由移动。目前，移动床生物膜反应器采用的填料多为聚乙烯、聚丙烯塑料等，密度一般为0.96g/cm3左右，填料的容积表面积大，可达200～500m2/m3。 ③出水装置 出水装置要求把载体拦截在反应器中，同时不为出流的生物膜或活性污泥堵塞。出水装置的孔径取决于生物填料的外观尺寸。 ④曝气或搅拌系统 一般采用中小孔曝气管，要求布气均匀，采用曝气可以达到供氧和流化的双重功能。 ⑶生物移动床反应器主要工艺特征 ①反应速率高 ②水头损失小、不易堵塞、无须反冲洗，一般不需回流。 ③污水处理厂改造升级方便。 ④系统控制管理较方便。
膜生物反应器 科技名词定义 膜生物反应器 membrane bioreactor;MBR 定义1： 膜技术与生物技术结合的使系统出水水质和容积负荷都得到大幅提高的一种污水处理装置。 所属学科： 海洋科技（一级学科）；海洋技术（二级学科）；海水资源开发技术（三级学科）定义2： 一种含有固定酶或细胞、可用来促进特定生物化学反应的反应器。是工业生化在生产工艺上采用的一种膜技术。 简介 膜生物反应器 膜-生物反应器（Membrane Bio-Reactor,MBR）为膜分离技术与生物处理技术有机结合之新型态废水处理系统。是一种由膜分离单元与生物处理单元相结台的新型水处理技术，以膜组件取代二沉池在生物反应器中保持高活性污泥浓度减少污水处理设施占地，并通过保持低污泥负荷减少污泥量。主要利用沉浸于好氧生物池内之膜分离设备截留槽内的活性污泥与大分子固体物。因此系统内活性污泥（MLSS）浓度可提升至10,000mg/L，污泥龄(SRT)可延长30天以上，于如此高浓度系统可降低生物反应池体积，而难降解的物质在处理池中亦可不断反应而降解。故在膜制造技术不断提升支援下，MBR处理技术将更加成熟并吸引着全世界环境保护工业的目光，并成为21世纪污水处理与水资源回收再利用唯一选择。 用途
污水处理:中国是一个缺水国家,污水处理及回用是开发利用水资源的有效措施。污水回用是将城市污水通过膜生物反应器等设备的处理之后,将其用于绿化、冲洗、补充观赏水体等非饮用目的,而将清洁水用于饮用等高水质要求的用途。城市污水就近可得,免去了长距离输水:其在被处理之后污染物被大幅度去除,这样不仅节约了水资源,也减少了环境污染。污水回用已经在世界上许多缺水的地区广泛采用,被认为具有显著的社会、环境和经济效益。 迸出水水质比较: 设计进水水质:BOD5<30Omg/l CODcr<50Omg/l SS<30Omg/l T--N<4-5mg/l 出水水质:BOD5<5mg/l NH4+-N<1.Omg/l CODcr〈2Omg/l 浊度<1NTU 膜生物反应器 SS=Omg/l 细菌总数<20个/ml T-N<0.5mg/l 大肠杆菌数未检出 膜的种类繁多,按分离机理进行分类,有反应膜、离子交换膜、渗透膜等;按膜的性质分类,有天然膜(生物膜)和合成膜(有机膜和无机膜) ;按膜的结构型式分类,有平板型、管型、螺旋型及中空纤维型等。 工艺 膜生物反应器(MBR)是杨造燕教授及其领导的科研小组历经10年时间研究开发出来的新型污水生物处理装置,该技术被称为"21世纪的水处理技术",该项目曾被列为国家八?五、九?五重点科技攻关项目并被国家列为"中国21世纪议程实施能力及可持续发展实用新技术",此项技术在国内处于领先水平,部分指标达到国际领先水平。 MBR是膜分离技术与生物处理法的高效结合,其起源是用膜分离技术取代活性污泥法中的二沉池,进行固液分离。这种工艺不仅有效地达到了泥水分离的目的,而且具有污水三级处理传统工艺不可比拟的优点: 1、高效地进行固液分离,其分离效果远好于传统的沉淀池,出水水质良好,出水悬浮物和浊度接近于零,可直接回用,实现了污水资源化。
MBBR移动床工艺的应用 MBBR移动床工艺在城市污水处理厂升级改造中的 应用 摘要：本文介绍了移动床生物膜污水处理工艺在城市污水处理厂升级改造和工业污水深度处理回用中的应用实例，列举了MBBR生物膜工艺与活性污泥工艺组合工艺在城市和工业污水处理厂改造中 应用的效果。 关键词：MBBR工艺，MBBR和活性污泥组合工艺，升级改造，脱氮除磷1 MBBR工艺特点移动床生物膜污水处理工艺（Moving Bed Bio-film Reactor简称MBBR）采用的生物载体是聚乙烯中空圆柱体，内部有十字支撑，外部有翅片，密度0.95 g／cm2左右，可供生物膜附着的有效比表面积500 m2／m3以上。这种载体的密度和特殊形状使微生物在有保护的载体内表面生长而更加有效的去除废水中的污染物，MBBR和它与各种活性污泥的组合工艺被北欧的瑞典安能士公司(Anox)和挪威卡能士公司（Kaldnes）（现两公司合并为瑞典国际集团Anoxkaldnes Global）推广应用到47个国家和地区，现已具有500个大中型市政和工业污水处理厂工程应用实例。该工艺具有以下特点： 1) 占地面积小：在生物填料填充率在67%左右和相同的污染负荷的条件下，MBBR生物处理池约占常规生物处理池（包括厌氧/缺氧/好氧） 20-30％的池容。 2) 适合于污水处理厂的扩容：由于MBBR生物池的设计可根据污染负荷的大小使其内生物填料的填充率控制在10％-67%之间，所以，当实际运行进水水质或水量发生变化时，只通过提高填料填充率，即可保证原设计生物池容不变的情况下， 满足原设计出水标准。 3) 适合于现有城市和工业污水处理厂的升级改造：MBBR工艺在设计和运行上具有灵活简单的特点，一是它可以采用各种池型(深浅方圆/不同建筑结构)，而不影响工艺的处理效果；二是它可
第三章固定床生物处理技术 3.1 概述 利用微生物在固体表面的附着生长（Attached Growth）对废水进行生物处理的技术，在传统上称为生物膜法，主要包括生物滤池、生物转盘、生物接触氧化法、生物流化床法等。生物膜法的基本原理就是通过废水与生物膜的相对运动，使废水与生物膜接触，进行固液两相的物质交换，并在膜内进行有机物的生物氧化，使废水获得净化。同时，生物膜内微生物不断得以生长和繁殖。与微生物悬浮生长的活性污泥法相比，生物膜法具有许多明显的优点。主要表现在： (1) 由于存在许多生长繁殖速度缓慢的硝化细菌，因此具有较高的脱氮能力； (2) 生物膜中存在的微生物具有多样性，包括好氧菌、厌氧菌、真菌和藻类等，使其在去除污染物方面具有广谱性； (3) 大量微生物生长和占据了整个反应器的空间，单位体积生物量远比活性污泥法为高，因此单位处理能力巨大； (4) 膜法中的食物链比活性污泥法长，产生的污泥大都被生物所消耗，因此剩余污泥量很少； (5) 系统操作维护方便，能耗低，无需污泥回流； (6) 因系统的微生态复杂，对水力和有机负荷变化的承受能力强，操作运行稳定。 目前，膜法已不仅是一种好氧处理技术，相继出现了厌氧滤池、厌氧生物流化床等；而且，在反应器型式、膜支承材料种类和结构、操作运转方式等方面都有较大发展。从反应器的型式考虑，生物流化床技术已经发展成为废水生物处理的重要分支，因 ·63·
此放在下一章专门讨论，本章将重点讨论属于生物膜法的各种新型固定床附着生长技术。 固定床附着生长系统依据为微生物附着所提供的材料和填充形式不同，可分为填充床、软性填料床、网式或笼式床生物反应器、旋转盘片式生物反应器等。例如，普通生物滤池常采用碎石、焦炭、塑料滤料等各种填料，而塔式生物滤池则常用蜂窝状填料或鲍尔环等各种化工用填料。依据运行方式还可将固定床附着生长系统分为完全浸没式和半浸没式生物反应器。例如，软性填料床生物反应器都属于完全浸没式，而生物转盘常采用半浸没式。另外，依据对污染物的去除机理不同，还可分为好氧附着生长系统和厌氧附着生长系统。表3-1为几种常规的固定床附着生长系统的特点和主要设计参数。 3.2 生物滤池及其发展 3.2.1 干床生物滤池（dry bed filtration） 干床生物滤池最早出现在本世纪初，一直被应用在饮用水的·64·
固定床-流化床-浆态床的优缺点
固定床反应器 定义：气体流经固定不动的催化剂床层进行催化反应的装置。 特点：结构简单、操作稳定、便于控制、易实现大型化和连续化生产等优点，是现代化工和反应中应用很广泛的反应器。 应用：主要用于气固相催化反应。 基本形式：轴向绝热式、径向绝热式、列管式。 固定床反应器缺点： 床层温度分布不均匀； 床层导热性较差； 对放热量大的反应，应增大换热面积，及时移走反应热，但这会减少有效空间。 流化床反应器（沸腾床反应器） 定义：流体（气体或液体）以较高流速通过床层，带动床内固体颗粒运动，使之悬浮在流动的主体流中进行反应，具有类似流体流动的一些特性的装置。 应用：应用广泛，催化或非催化的气—固、液—固和气—液—固反应。 原理：固体颗粒被流体吹起呈悬浮状态，可作上下左右剧烈运动和翻动，好象是液体沸腾一样，故流化床反应器又称沸腾床反应器。 结构：壳体、气体分布装置、换热装置、气—固分离装置、内构件以及催化剂加入和卸出装置等组成。 优点：传热面积大、传热系数高、传热效果好。进料、出料、废渣排放用气流输送，易于实现自动化生产。 缺点：物料返混大，粒子磨损严重；要有回收和集尘装置；内构件复杂；操作要求高等。 固定床： 一、固定床反应器的优缺点 凡是流体通过不动的固体物料形成的床层面进行反应的设备都称为固定床反应器，而其中尤以利用气态的反应物料，通过由固体催化剂所构成的床层进行反应的气固相催化反应器在化工生产中应用最为广泛。气固相固定床反应器的优点较多，主要表现在以下几个方面： 1、在生产操作中，除床层极薄和气体流速很低的特殊情况外，床层内气体的流动皆可看成是理想置换流动，因此在化学反应速度较快，在完成同样生产能力时，所需要的催化剂用量和反应器体积较小。 2、气体停留时间可以严格控制，温度分布可以调节，因而有利于提高化学反应的转化率和选择性。 3、催化剂不易磨损，可以较长时间连续使用。 4、适宜于高温高压条件下操作。 由于固体催化剂在床层中静止不动，相应地产生一些缺点： 1、催化剂载体往往导热性不良，气体流速受压降限制又不能太大，则造成床层中传热性能较差，也给温度控制带来困难。对于放热反应，在换热式反应器的入口处，因为反应物浓度较高，反应速度较快，放出的热量往往来不及移走，
总第194期2012年第2期 HEBEI M ETALLU R GY Total N o．1942012， N umber 2收稿日期：2011－12－30 作者简介：冯振勇（1973－），男，工程师， 1996年毕业于本溪冶金高等专科学校，现在河北钢铁集团承钢公司动力厂工作，E －mail ：xx_dl _fengzy@cdvt．com．cn 移动床膜生物反应器 在废水处理回用工程中的应用研究 冯振勇1，张国祥1，姚志强1 ，李 强2，冯俊强2，段建新 1 （1．河北钢铁集团承钢公司，河北承德067002；2．威立雅水处理技术（上海）有限公司，上海200001）摘要：介绍了移动床膜生物反应器（MBBR ）的工作原理、特点以及在钢厂综合废水治理中的首次应用情况。运行实践表明， MBBR 具有较强的抗负荷冲击能力，水质水量的剧烈波动不会引起出水水质的较大变化。软化处理后的钢厂综合废水经MBBR 处理后，出水COD 保持在10mg /L 左右，氨氮低于1mg /L ，pH 值稳定在7 8，SS ＜5mg /L ，且对碱度的贡献约30mg /L ，保证了回用水水质。关键词：移动床膜生物反应器；废水；处理；中水回用；研究中图分类号：X756 文献标识码：A 文章编号：1006－5008（2012）02－0074－04 APPLICATION RESEARCH OF MOVING BED －FILM BIOREACTOR IN WASTE WATER PROCESSING SYSTEM Feng Zhenyong 1，Zhang Guoxiang 1，Yao Zhiqiang 1，Li Qiang 2，Feng Junqiang 2，Duan Jianxin 1 （1．Chengde Iron and Steel Company ，Hebei Iron and Steel Group ，Chengde ，Hebei ，067002；2．Weiliya Water Treatment Technique （Shanghai ）Co．，Ltd．，Shanghai ，200001） Abstract ：It is introduced the work principle and features of the moving bed －film bioreactor and its first ap-plication in comprehensive waste water treatment of iron and steel business．It is showed from the practice that MBBR has strong ability to resist load compact ，so the quality of outgoing water would not be affected by serious fluctuation of intake water＇s quality and quantity．The softened comprehensive waste water of steel-making plant is treated with MBBR ，and its outgoing water has COD at 10mg /L level ，ammonia and nitro-gen lower than 1mg /L ，pH steady at 7to 8，SS lower than 5mg /L ，and a contribution of basicity given with about 30mg /L ，the backwater quality gets guaranteed． Key Words ：moving bed －biofilm reactor ；waste water ；treatment ；medium water reusing ；research 1前言河北钢铁集团承德新新矾钛股份有限公司（以下简称“承钢”）响应国家节能号召，实现生产废水零排放， 2009年10月开始建设废水处理回用二期工程， 生产废水经软化、澄清并去除有机物和氨氮后作为生产补水全部回用，项目于2010年11月完成调试正式投入运行。在二期工程中，承钢在传统混凝沉淀+石灰软化工艺的基础上，创新性地采用了法国威立雅公司的移动床膜生物反应器MBBR 对废水中的有机污染物和氨氮作进一步的去除，以满足回用水的要求。 2 移动床膜生物反应器MBBR 概况 移动床膜生物反应器MBBR （Moving Bed Bio- film Reactor ）是挪威AnoxKaldnes 公司于1985发明的，后该公司被纳入威立雅集团旗下。该专利技术经过20多年的应用和完善，已成为一种成熟的除碳、硝化、反硝化工艺被广泛应用。目前在全世界已经有500多项应用案例。 2．1 MBBR 技术工作机理 MBBR 工艺核心部分就是以比重接近于水的悬浮填料直接投加到曝气池中作为微生物的活性载体，依靠曝气池内的曝气和水流的提升作用处于流化状态 ［1］ 。与以往的填料不同的是，悬浮填料能与污水不间断地接触，且接触非常充分，因此被称为“移动的生物膜”。 利用生长生物膜的悬浮载体，通过与废水的不
本文极具参考价值，如若有用请打赏支持我们！不胜感激！ 【专业知识】移动床生物膜污水处理装置 【学员问题】移动床生物膜污水处理装置？ 【解答】移动生物膜床反应器作为一种新型高效的生物膜法污水处理装置，是对现有固定填料式生物接触氧化法和生物流化床的改进。它的基本设计思想是开发一种处理能力高，能够连续运行，不发生堵塞的生物膜反应器，并且不需要反冲洗，水头损失小，能耗低，管理运行简单方便。该反应器中的投加一种圆柱状轻质悬浮移动填料，填料具有较高的比表面积，比重接近与1.生物膜可在填料上大量生长。在好氧反应器中，通过曝气的作用，推动填料随水流移动，在缺氧或厌氧反应器中，通过机械搅拌使填料移动。良好的水力条件，使气液固之间维持很高的传质速率，填料上的生物膜具有较高的生物活性。从而使得移动生物膜反应器具有比普通活性污泥法和生物膜法更高的处理能力，简便的运行操作。 技术原理及工艺流程：①研制生产出处理水量为10m3/h的地理式移动床生物膜装置一套，设计了处理水量为20m3/h的地理式移动床生物膜污水处理工程一项；②应用移动床生物膜装置处理低浓度生活污水时，COD进水浓度为100―280mg/L，水力停留时间2―4h内（一般活性污泥法和生物膜法为6h以上），COD去除率达60―90%，气水比3―4∶1（一般生物膜法为10―12∶1）；③在常温下利用厌氧复合床生物膜反应器处理高浓度有机废水，取得了良好的效果。在进水COD浓度5300―20140mg/L 的范围内，容积负荷为5.38―20.62kgCOD/m3？d，水力停留时间为0.98d的条件下，COD去除率最高达98%，平均为90%.④本研究所开发的移动式生物膜轻质填料的比表
序批式生物膜工艺（SBBR)的简述 A11环工顾雪莲 110107129 摘要：研究了SBBR工艺的工作原理，对SBBR工艺进行了分类，探讨了SBBR 工艺的特点和SBBR工艺的运行影响因素。阐述了SBBR工艺在水处理中的应用，得出了SBBR工艺在处理废水中氮磷处理效果。 关键词：水处理SBBR工艺基本原理 1、SBBR工艺的工作原理 SBBR工艺是在SBR工艺基础上发展起来的一种工艺。在SBR反应器内装填粘土、砂砾、无烟煤颗粒等惰性颗粒填料，或活性炭、海绵及一些形状特殊的塑料填料，按照SBR 的运行方式，具有SBR工艺与生物膜法的优点，可以在一个反应器内通过厌氧、缺氧、好氧等不同工序的控制来实现污水处理。SBBR处理废水操作过程也包括5个阶段进水、反应、沉淀、出水、闲置。每个SBR反应器在处理废水时都是一个完整的过程，以一定时间顺序间歇操作。SBBR反应器不存在空间上控制的障碍，只需在时间上有效地控制和交换。 2、SBBR工艺的分类 序批式固定床生物膜反应器：采用固体物质作为微生物载体，常用填料有粘土类无机填料、形态不同的塑料填料类、纤维或纤维与塑料复合的组合填料等。 运行模式为进水、反应、排水三个阶段。 序批式膜生物膜反应器：采用特制的浸没在水中的气体可透过微孔膜，它既作曝气装置有作为微生物的载体。 序批式流动床生物膜反应器:主要特征是流动床中附着生长的载体不固定，在反应器中处于连续流动状态。流动床生物膜反应器主要包括：生物流化床、 气提式生物膜反应器、厌氧生物膜膨胀床和移动床生物膜反应器。 SBBR工艺由于周期性的好氧、缺氧状态的交替出现，可以抑制丝状菌的过度繁殖，从而防止污泥膨胀；间歇式的运行方式使生物膜上的微生物分布较为均匀，适合生长速率较慢的微生物的附着生长。微生物生长在生物膜系统中可以大大减轻有毒物质、PH值和温度极限引起的抑制中毒作用。间歇式的运行方式使生物膜内外层的微生物达到最大的生长速率和最好的活性状态，从而提高了系统对水质水量的应变能力, 增强了系统的抗冲击负荷能力。同时,间歇式的运行方式可以通过改变反应参数来保证出水水质。生物量多、复杂、剩余污泥量少,动力消耗少:；生物膜固定在填料表面, 可以稳定生态条件, 从而能够栖息增殖速度慢, 世代时间长的细菌和较高级的微生物与生物膜反应器相比, 间歇进水、周期性供氧的改变保证了微生物种类的丰富和活性, 并且由于微生物在膜内的位置发生变化, 使得生物膜具有复杂的生态系统和空间结构。此外, 由于生物膜对微生物的截留, 实现了HRT和SRT 的分离, 因而在有机物, N, P 的去除方面显示出巨大潜力。 3、SBBR工艺的特点 SBBR的进水方式有限制性和非限制性两种。限制性进水方式是指在进水阶段，反应器内不进行曝气；非限制性进水方式是指在进水阶段同时对反应器进行曝气。对限制性和非限制性两种进水方式在不同处理周期中的试验可知在处理废水过程中，采用限制性进水方式能得到比非限制性进水方式更好的效果。主要原因是因为中段废水质量浓度较低，可化性差，有机物难以降解，限制性进水的厌氧状态有利于难降解的有机物分解，从而提高了处理效率。
图片简介: 本技术涉及一种快速去除硝酸根的方法，在溶液储槽中加入驯化完成并活化好的反硝化细菌和反硝化细菌标准培养基；将溶液储槽中的菌液泵入装有陶粒载体的生物反应器，定时分析生物反应器内菌液的硝酸根浓度，当其去除率超过90%时，将菌液排干；加入新鲜培养基继续定时分析生物反应器内溶液的硝酸根浓度，当其去除率超过90%时，将菌液排干；直至生物反应器中硝酸根去除率超过90%所需时间基本恒定时，挂膜工作完成；将需要去除硝酸根的溶液转入溶液储槽中，去除溶液中硝酸根。一种移动床生物反应器装置，包括溶液储槽、生物反应器、载体再生槽，所述溶液储槽通过管道连接生物反应器以加入培养基，所述生物反应器下端设有载体排放阀与载体再生槽连接。 技术要求 1.一种快速去除硝酸根的方法，利用移动床生物反应器，采用筛选后的生物陶粒作载体固定反硝化细菌，增大生物反应器中细菌数量，实现快速去除硝酸根的目的；其步骤如 下： 1）制备菌液：在溶液储槽中加入驯化完成并活化好的反硝化细菌和反硝化细菌标准培养基，所述反硝化菌种与其培养基的体积比为1:1～100，然后通过搅拌器搅拌混匀；
2）载体预处理：将Φ3～5mm的陶粒载体浸泡，清洗，装入生物反应器中，陶粒载体装入量以离生物反应器顶部10～15cm为准； 3）挂膜： a、将溶液储槽中的按一定比例接种的菌液泵入生物反应器内，体积以溶液刚好淹没陶粒载体为准，静置； b、定时分析生物反应器内菌液的硝酸根浓度，当其去除率超过90%时，将菌液排干； c、加入新鲜培养基至刚好淹没陶粒载体为准，静置，继续定时分析生物反应器内溶液的硝酸根浓度，当其去除率超过90%时，将菌液排干； d、重复c步骤，直至生物反应器中硝酸根去除率超过90%所需时间基本恒定时，挂膜工作完成； 4）硝酸根连续去除：挂膜完成后，将需要去除硝酸根的溶液转入溶液储槽中，pH6～8、硝酸根浓度0.1～1g/L，启动恒流泵，从生物反应器上方加入需要去除硝酸根的溶液，开始阶段需要去除硝酸根的溶液流量为每小时0.01～0.05倍生物反应器塔内有效体积，直至从出液阀流出的菌液中硝酸根去除率达到90%以上，然后再逐步调大需要去除硝酸根的溶液进入生物反应器的流量至每小时0.05～0.5倍生物反应器有效体积，从而实现溶液中硝酸根的快速连续去除。 2.根据权利要求1所述的快速去除硝酸根的方法，其特征在于：载体预处理的过程如下： 将Φ3～5mm的陶粒载体置于载体再生槽中，加自来水浸泡，启动空压机、打开进气阀通入压缩空气，搅拌一段时间后，关闭空压机及进气阀； 然后打开隔膜阀，放掉洗液，再加清水漂洗陶粒载体至洗水变澄清，然后打开出料阀，启动隔膜泵将陶粒载体转移到生物反应器中。 3.根据权利要求1或2所述的快速去除硝酸根的方法，其特征在于：
移动床生物膜反应器的研究及应用现状 王 奕 张兴文 杨凤林 (大连理工大学环境科学与工程学院,大连116012) 摘 要 移动床生物膜反应器是一种高效的污水处理系统,目前在国内外已有较多应用。本文就其特点及研究应用 状况作简要介绍。 关键词 研究 应用 移动床生物膜反应器 The stu dy and application of moving bed biofilm reactor Wang Yi Zhang Xingwen Yang Fenglin (S chool of Environmental Science &Engineering ,Dalian University of Technology ,Dalian 116012) A bstract A highly effective and compact reactor ,named moving bed biofilm reactor (M BBR )w as devel -oped recently .Its characteristics and application were presented . Key words study ;application ;moving bed biofilm reacto r 近年来,随着人类环境保护意识的提高,国内外对废水排放的限制标准越来越严格,因此,在研究开发新型、高效的污水处理技术的同时,迫切需要在原有污水厂的基础上改进处理工艺,提高污水处理效果。M BBR 就是基于这种思想开发出来的。1988 年,为了解决污水厂传统活性污泥法污泥沉降困难、易流失的问题,增强脱氮功能,挪威Kaldnes Mi -jecpteknog i 公司与SINTEF 研究机构联合开发了一种新型生物膜反应器 [1] 。该反应器工艺简单,提高 了污水厂的脱氮效率,改善了运行效果,同时又不需增加原有反应器的容积。这就是最初的KM T 移动床生物膜反应器(M BBR )。后来一些学者对其进行了研究和改进 [2,3] ,使其更多地应用到实际生产中。 1 MBBR 原理及特点 1.1 原 理 移动床生物膜反应器的主要原理是污水连续经过装有移动填料的反应器时,在填料上形成生物膜,生物膜上微生物大量繁殖,起到净化污水的作用(见图1)。 1.2 反应器的特点 移动床生物膜反应器是在生物滤池和流化床的工艺基础上发展起来的。它既具有传统生物膜法耐冲击负荷、泥龄长、剩余污泥量少的特点,又具有活 性污泥法的高效性和运转灵活性。移动床生物膜反 应器模拟了大自然生态系统中水体的自净功能。在自然系统中,水体中起自净作用的微生物大致可分成两类:一是附着生长在各种物体表面的微生物;二 是水中悬浮微生物,如菌类絮状物、甲壳类动物以及各种鱼类。移动床生物膜反应器中的悬浮微生物和 填料上的微生物分别类似于自然水体中的悬浮微生 物和附着生长的微生物。与传统的活性污泥法相比,M BBR 具有以下几个特点[4]: (1)改善系统的稳定性和运行性能; (2)提高系统的有机负荷和效率;(3)水头损失小、不易堵塞、无需反冲洗,一般不需回流。 图1 M BBR 简图 1.3 填料的特点 填料是移动床生物膜反应器的重要组成部分, 其性能关系到系统的应用和处理效果。填料一般比表面积较大、耐腐蚀和耐磨性较好且质量轻。在好氧反应器中,通过曝气推动填料随水流移动;在缺氧或厌氧反应器中,通过机械搅拌使填料移动。 第3卷第7期环境污染治理技术与设备 V ol .3,N o .72002年7月Techniques and Equipment for Environmental Pollution Control Jul .2002
固定床反应器.txt 固定床反应器单元仿真培训系统 操作说明书 北京东方仿真软件技术有限公司 二〇〇六年十月 目录 一、工艺流程说明 2 1、工艺说明 2 2、本单元复杂控制回路说明 2 3、设备一览 2 二、固定床反应器单元操作规程 3 1、开车操作规程 3 2、正常操作规程 4 3、停车操作规程 4 4、联锁说明 5 5、仪表及报警一览表 6 三、事故设置一览 7 四、仿真界面 8 附：思考题 10 一、工艺流程说明 1、工艺说明 本流程为利用催化加氢脱乙炔的工艺。乙炔是通过等温加氢反应器除掉的,反应器温度由壳侧 中冷剂温度控制。
主反应为：nC2H2＋2nH2?（C2H6）n，该反应是放热反应。每克乙炔反应后放出热量约为34000千卡。温度超过66℃时有副反应为：2nC2H4?（C4H8）n，该反应也是放热反应。 冷却介质为液态丁烷，通过丁烷蒸发带走反应器中的热量，丁烷蒸汽通过冷却水冷凝。 反应原料分两股,一股为约-15℃的以C2为主的烃原料,进料量由流量控制器FIC1425控制;另一股为H2与CH4的混合气,温度约10℃,进料量由流量控制器FIC1427控制。FIC1425与FIC1427为比值控制,两股原料按一定比例在管线中混合后经原料气/反应气换热器(EH-423)预热,再经原料预热器(EH-424)预热到38℃,进入固定床反应器(ER-424A/B)。预热温度由温度控制器TIC1466通过调节预热器EH-424加热蒸汽(S3)的流量来控制。 ER-424A/B中的反应原料在2.523MPa、44℃下反应生成C2H6。当温度过高时会发生C2H4聚合生成C4H8的副反应。反应器中的热量由反应器壳侧循环的加压C4冷剂蒸发带走。C4蒸汽在水冷器EH-429中由冷却水冷凝,而C4冷剂的压力由压力控制器PIC-1426通过调节C4蒸汽冷凝回流量来控制,从而保持C4冷剂的温度。 2、本单元复杂控制回路说明 FFI1427：为一比值调节器。根据FIC1425（以C2为主的烃原料）的流量，按一定的比例，相适应的调整FIC1427（H2）的流量。 比值调节：工业上为了保持两种或两种以上物料的比例为一定值的调节叫比值调节。对于比值调节系统，首先是要明确那种物料是主物料，而另一种物料按主物料来配比。在本单元中，FIC1425（以C2为主的烃原料）为主物料，而FIC1427（H2）的量是随主物料（C2为主的烃原料）的量的变化而改变。 3、设备一览 EH-423：原料气/反应气换热器 EH-424：原料气预热器 EH-429：C4蒸汽冷凝器 EV-429：C4闪蒸罐 ER424A/B：C2X加氢反应器 二、固定床反应器单元操作规程 1、开车操作规程 本操作规程仅供参考，详细操作以评分系统为准。 装置的开工状态为反应器和闪蒸罐都处于已进行过氮气冲压置换后，保压在0.03MPa状态。可以直接进行实气冲压置换。 1.1、EV-429闪蒸器充丁烷 (1)确认EV-429压力为0.03 MPa。 (2)打开EV-429回流阀PV1426的前后阀VV1429、VV1430。 (3)调节PV1426(PIC1426)阀开度为50%。 (4)EH-429通冷却水，打开KXV1430，开度为50%。 (5)打开EV-429的丁烷进料阀门KXV1420，开度50%。 (6)当EV-429液位到达50%时，关进料阀KXV1420。 1.2、ER-424A反应器充丁烷 (1)确认事项 ①反应器0.03 MPa保压。 ②EV-429液位到达50％。 (2)充丁烷 打开丁烷冷剂进ER-424A壳层的阀门KXV1423，有液体流过，充液结束；同时打开出ER-424A壳层的阀门KXV1425。
流动床生物膜反应器（MBBR）在污水处理中的应用一、前言 随着现代城市的发展，工业废水量和生活污水量逐年增长，城市水污染问题日益突出，治理水污染已经成为各地经济和社会发展的重要环节。废水的生物处理法自19世纪末发展至今，已成为世界各国处理城市生活污水和工业废水的主要手段，新技术、新工艺得到快速发展。废水的生物处理方法可以分为好氧生物处理和厌氧生物处理两大类，而好氧生物处理作为主要处理方法在废水处理领域中一直占据主要的地位。 根据曝气池内微生物生长环境、集结形态等的不同来分类，好氧生物处理方法基本可以分为两大类。第一类方法可以称为悬浮污泥法，主要包括传统活性污泥法和其变种，如阶段曝气法、渐减曝气法、完全混合活性污泥法、序批式活性污泥法（SBR）、生物吸附氧化法（AB法）、延时曝气法、氧化沟等。该方法中微生物与悬浮物质、胶体物质等混杂在一起形成具有较强吸附分解有机物能力的絮状体颗粒。第二类方法为生物膜法（或称附着污泥法），如生物滤池、塔式生物滤池、生物转盘、接触氧化法等。该方法生物或固定生长，或附着生长于固体填料（或称载体）表面。其中接触氧化法因具有BOD 负荷高、处理时间短、耐负荷冲击等优点近年来有了很多工程应用。 流动床生物膜（内循环生物流化床）处理方法是将活性污泥法和
生物膜法的结合，在生物流化床中，空气－污水－附有生物膜的载体在流化床中进行生物反应，可承受较高的BOD负荷。 近年江苏沃奇环保公司引进瑞典皇家理工学院、瑞典斯德哥尔摩大学及芬兰赫尔辛基理工大学等诸多北欧名校，水环境研究机构的工业污水处理先进技术，并与国家级科研部门合作，不断对对流动床生物膜技术进行改造与升级，使工艺技术更加完善，处理效率更加高效。该先进技术应用于焦化、医药、农药、染化等污水处理领域，十分有效地解决了高难度工业污水处理存在的技术难题。 二、流动床生物膜处理技术原理 MBBR工艺原理是通过向反应器中投加一定数量的悬浮载体，提高反应器中的生物量及生物种类，从而提高反应器的处理效率。由于填料密度接近于水，所以在曝气的时候，与水呈完全混合状态，微生物生长的环境为气、液、固三相。载体在水中的碰撞和剪切作用，使空气气泡更加细小，增加了氧气的利用率。另外，每个载体内外均具有不同的生物种类，内部生长一些厌氧菌或兼氧菌，外部为好养菌，这样每个载体都为一个微型反应器，使硝化反应和反硝化反应同时存在，从而提高了处理效果。 MBBR工艺兼具传统流化床和生物接触氧化法两者的优点，是一种新型高效的污水处理方法，依靠曝气池内的曝气和水流的提升作用使载体处于流化状态，进而形成悬浮生长的活性污泥和