同步脱氮除磷新工艺处理校园生活污水

针对国内现行工艺氮磷去除不能兼顾的现实,采用活性污泥、生物膜组合系统(活性污泥、生物膜培养采用原水→配水→待处理废水逐级诱导培养获得单池相对纯净的生物相.避免了硝化菌与聚磷菌的泥龄矛盾,利用反硝化聚磷"一碳两用"缓解了碳源竞争问题),并采用独特的聚磷污泥回流方式使全部聚磷菌污泥经历释磷、聚磷循环,克服了水体中氮磷去除不能兼顾的问题.运行结果表明,该工艺对校园生活污水有良好的处理效果.当进水的CODCr、NH 4-N、TN、PO3-4-P的平均浓度为349.84mg·L-1、32.28mg·L-1、35.76mg·L-1、6.45mg·L-1时,出水平均浓度为14.77mg·L-1、1.46mg·L-1、5.48mg·L-1、0.63mg·L-1,平均去除率分别为95.7%、95.12%、84.45%、92.01%.长期的运行表明此工艺对氮磷有稳定的去除效果,出水水质满足国家<城镇污水处理厂污染物排放标准>(GB18918-2002一级B标准)要求.     

高效厌氧氨氧化颗粒污泥膨胀床(EGSB)工艺性能研究

采用模拟含氨废水和颗粒污泥膨胀床(EGSB)反应器研究了厌氧氨氧化工艺的高效性能.试验结果表明,厌氧氨氧化EGSB工艺具有很高的容积效率,在35℃、进水氨氮浓度247.1～444.8mg·L-1、亚硝氮浓度为308.7～483.8mg·L-1的条件下,反应器水力停留时间可缩至0.237～0.267h,平均容积去除速率可高达61.4kg.m-.3d-1(以N计).同时,该工艺具有超常的运行稳定性,在进水基质浓度、进水流量和pH波动的情况下,总氮去除率和出水浓度的相对标准偏差分别为3.6%～6.9%和14.4%～22.6%.厌氧氨氧化EGSB工艺的高效稳定性可归因于反应器的强污泥持留能力和厌氧氨氧化污泥的高反应活力.系统内持留的污泥浓度高达24～28g·L-1(以VSS计),分批培养测得的最高比污泥活性为2.19g.g-1.d-1(以N计),连续培养测得的最高比污泥活性为3.62g.g-.1d-1(以N计).     

好氧颗粒污泥和活性污泥细菌种群结构对五氯酚污染的响应研究

应用一种新的微生物分子生态学方法--末端限制性片段长度多态性(T-RFLP)法研究了好氧颗粒污泥和活性污泥在毒性化合物五氯酚(PCP)影响下的废水处理性能及其微生物种群结构的响应.结果表明,PCP浓度为30 mg·L-1时,颗粒污泥和活性污泥的COD去除率为38%、77%,与10～20 mg·L-1 PCP相比,分别下降了56%和15%.另外,PCP浓度为20 mg·L-1时,去除率为13%和58%,与10～20 mg·L-1 PCP相比,分别下降了86%和40%,说明PCP对氨氮去除率的影响大于对COD去除率的影响,对颗粒污泥的影响大于对活性污泥的影响.PCP对好氧颗粒污泥和活性污泥的细菌种群结构都产生了明显的影响,而且好氧颗粒污泥的变化程度大于活性污泥;PCP浓度为30 mg·L-1时,好氧颗粒污泥中的细菌种群数量明显下降,TRFs片段数从26下降到14,但活性污泥中的细菌种群数量基本不变,污泥中细菌种群结构的变化趋势与污泥的水处理性能的变化趋势相一致.     

颤蚓对活性污泥沉降性能的影响

系统考察了低、中、高3种不同污泥浓度下(TSS≈4 g·L-1、6 g·L-1和8 g·L-1),一定的颤蚓投加比例对活性污泥沉降性能的影响,并同时考察了颤蚓对污泥特性的影响.研究结果表明,投加颤蚓后60min内,活性污泥沉降速率明显加快,60min时的污泥容积相对于未投加颤蚓前可减少8%～42%;而且.这种效应对污泥浓度高的活性污泥更为显著和有效.然而.通过对污泥特性的分析表明,颤蚓在短时间内(1～3h)对污泥平均粒径、Zeta 电位并无多少影响;此时污泥容积指数(SVI)和胞外聚合物含量(EPS)却反而略有增加.     

铜离子与解偶联剂协同下的污泥减量作用

采用间歇式活性污泥培养装置,以2,6-二氯苯酚（DCP）作为解偶联剂,浓度为20 mg/L,Cu^2＋浓度为1 mg/L,加入到间歇式活性污泥反应器中.通过30　d的连续运行发现,COD去除效率相比对照实验下降7％,污泥减量达75％,且出水中DCP的平均浓度为0.28 mg/L,Cu^２＋的去除率达到90％以上,但污泥沉降性和污泥对N、P的去除率下降,污泥活性也降低.镜检发现,污泥中丝状菌增多,原生动物和后生动物数量和种类减少.结果表明,Cu^２＋和DCP对污泥减量有明显的协同作用,在活性污泥工艺中运用铜离子和解偶联剂联合来限制污泥产率是可行的.     

倒置A2O污水处理厂PFOS和PFOA的浓度分布特征及其总量分析

为考察全氟辛烷磺酸(PFOS)和全氟辛酸(PFOA)在倒置A2O污水处理厂各工艺段的浓度分布规律与去除效率,采用固相萃取(SPE)和高效液相色谱-质谱联用(LC-MS/MS)技术,检测分析了北京市卢沟桥污水处理厂夏季和冬季各工艺段污水和污泥中PFOS和PFOA的浓度.结果显示,PFOS在污水与污泥中的浓度均大于PFOA;进水中PFOS和PFOA的浓度分别为113.9~160.6 ng·L-1和14.7~68.1 ng·L-1,出水中的浓度分别为60.1~232.6 ng·L-1和29.9~71.5 ng·L-1;PFOS和PFOA在倒置A2O工艺没有得到有效去除.同时发现,PFOS在污泥中的浓度随季节变化较大,且其在污泥中的分配比高于PFOA;PFOS的质量流在工艺流程的各阶段变化较大,而PFOA没有明显的变化和差别.进水中PFOS和PFOA的质量流经过污水处理厂处理后反而升高,有可能是由于前驱物质降解产生.     

膜-生物反应器和传统活性污泥法去除两种内分泌干扰物的对比研究

采用不主动排泥的运行模式,在相同污泥负荷条件下,对比研究了膜-生物反应器(MBR)与传统活性污泥反应器(CASR)对两种典型内分泌干扰物--双酚A(BPA)与壬基酚聚氧乙烯醚(NPnEO,n=1～4)的去除效果.结果表明,在BPA-污泥负荷与NPnEO-污泥负荷分别为0.046～10.2 g·kg-1·d-1与0.097-0.701 g·kg-1·d-1的范围内,MBR与CASR均能有效去除这2种内分泌干扰物.随着运行时间的延长,污泥对目标物质的去除能力逐渐加强;相比CASB,MBR对目标物质的去除更强且稳定.在获得相同的出水目标物质浓度条件下,MBR可以耐受更高的容积负荷.2种内分泌干扰物的投加对MBR和CASR的COD和NH4-N的去除均没有明显影响.     

采用EGSB+TCBS工艺处理有机颜料废水的实例

以某生产有机颜料厂家为例,介绍了EGSB TCBS处理工艺.当废水中CODCr质量浓度为7 000～8 000mg·L-1,NH3-N质量浓度为200～300 mg·L-1,SS的质量浓度为1 000～2 000 mg·L-1时,采用该工艺处理后,出水ρ(CODCr)＜1 000 mg·L-1,ρ(NH3-N)＜30 mg·L-1,ρ(SS)＜500 mg·L-1.表明EGSB TCBS工艺适应于有机颜料废水的处理,且工艺运行便利,剩余污泥量小.     

焦化废水活性污泥中降解硫氰化物细菌种群多样性分析

硫氰化物(SCN-)是焦化废水中COD的主要来源之一,其在生物处理工艺好氧段的去除效果直接影响出水的达标排放,活性污泥中的微生物种群在SCN-生物处理中发挥重要作用.以SCN-为唯一碳源和能源驯化活性污泥,研究其对100、300和600 mg·L-1SCN-浓度的去除降解效果,并利用454测序技术解析污泥中降解SCN-的细菌多样性.结果表明,驯化污泥能有效去除100~600 mg·L-1SCN-,SCN-浓度越高,去除速率越高,然而细菌群落多样指数越低;原始污泥和驯化污泥的细菌门类群主要为Proteobacteria、Bacteroidetes、Chlorobi、Planctomycetes、Acidobacteria、Nitrospira、Firmicutes和Unclassified,其中Proteobacteria和Bacteroidetes门占主导地位;Thiobacillus是主要的SCN-降解菌,在3个污泥样品中的丰度分别为3.07%、8.63%和0.27%.Thiobacillus是浓度小于300 mg·L-1SCN-时焦化废水中主要的SCN-降解菌,而在600 mg·L~(-1) SCN-高浓度时低丰度的SCN-降解菌群可能发挥协同降解作用.这些结果为揭示焦化废水处理SCN-污染物的去除机制提供了基础.     

曝气膜生物反应器运行过程中污泥活性特征变化及其对膜污染的影响

研究了曝气膜生物反应器运行过程中活性污泥主要活性特征变化及其对膜污染的影响.通过排出剩余污泥的办法维持活性污泥浓度在4000 mg·L-1左右,并连续运行75 d.运行期间,每日检测活性污泥的各项性质指标便于反映污泥特性的变化.结果表明,随着反应器运行时间的延长,污泥脱氢酶活性逐渐增加,其对反应器的运行有着两方面的作用,一方面会强化微生物对污染物的去除,但另一方面则导致了胞外聚合物的增加,并加速膜污染.而污泥表观产率则随着运行时间的延长先增加后有所减少,其粒径逐渐减小,且胞外聚合物呈现增加的趋势,总的出水水质情况逐渐提高,与此同时,反应器内原生动物及后生动物在运行前期较少,而在后期大量出现.膜污染分析结果表明运行后期膜污染速度明显加快,其原因在于:污泥粒径的减小以及胞外聚合物的增加导致细小颗粒及胞外聚合物堵塞或在膜表面沉积数量增加.     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.