两级曝气生物滤池用于生活污水的处理与研究

采用两级曝气生物滤池（BAF）工艺,对生活污水进行处理。试验研究了两级曝气生物滤池（BAF）工艺系统生物膜的培养过程和对CODC4,BOD5、SS、NH3-N等去除效果。试验结果表明生活污水经两级曝气生物滤池（BAF）工艺系统处理后,出水BOD,与CODC4分别低于10mg/L和40mg／L,SS小于10mg／L,浊度小于8NTU,色度小于15度,总磷小于3mg／L,NH3-N小于2mg／L,NO3-N小于5mg／L,细菌小于3个／mL,大肠杆菌未检出;CODCr,BOD5的去除率分别超过90％、95％,SS和NH3-N去除率接近100％,出水稳定,水质较好,符合国家污水综合排放的水质标准,有利于污水的再生利用。     

一种新型滤料在循环养殖水处理中的应用

实验研究了填充新型无剩余污泥悬浮型生物滤料的曝气生物滤池处理养殖废水的挂膜情况及水力停留时间（HRT）变化对曝气生物滤池处理效果及运行特性的影响。结果表明，含氨氮和亚硝酸氮浓度较高的模拟养殖污水用活性污泥挂膜，大约1个月就能使生物滤池启动。当模拟养殖污水氨氮起始浓度在2mg／L左右时最佳水力停留时间（HRT）为0．6h循环6d能使氨氮浓度降到0．03mg／L左右，亚硝酸氮有短期积累问题，但最终都能被降到0．05mg／L以下。水力停留时间影响氨氮的去除时间，从而影响亚硝酸氮的积累。水力停留时间（HRT）对有机物（CODMn）去除影响不大，且该种滤料对有机物（CODMn）去除效果较差，去除率在28％左右。     

曝气生物滤池应用于封闭循环海水养殖系统的试验研究

曝气生物滤池是封闭循环海水养殖系统的核心设备。现以封闭循环海水养殖系统中的曝气生物滤池为试验研究对象,考察了曝气生物滤池的挂膜过程及NH3-N初始质量浓度、循环流速、溶解氧（D0）、循环时间及温度对NH3-N去除效果的影响。试验表明,该曝气生物滤池的生物膜成熟快,当曝气生物滤池在正常养殖状态时．水的循环流速为130L／h可达到NH3-N最大去除率;水的循环流速为80IA可应对高浓度NH3-N负荷。在污水DO质量浓度为7．0mg／L,温度为34℃时,滤池有最大的NH3-N去除率。     

曝气生物滤池中碳和氮代谢特性

用充填陶瓷滤料的曝气生物滤池研究碳和氮代谢特性。曝气生物滤池进水氨氮为52mg／L左右、COD为100mg／L左右和回流比为200％时,经过20多d的运行,出水氨氮小于0．05mg／L、COD小于25mg／L、亚硝态氮为4．7mg／L和硝态氮为7．1mg／L,COD去除率达75％,氨氮去除率达99．9％,总氮去除率达78％;过大和过小的回流比对曝气生物滤池的运行性能都是不利的。研究成果可以应用于一般城市污水以及含低COD、高氨氮工业废水的处理。     

曝气量对间歇曝气/曝气生物滤池效能影响

研究间歇曝气/曝气生物滤池脱氮除磷效果,确定其最佳曝气量,为该种形式的曝气生物滤池高效运行提供依据。试验采用序批式曝气生物滤池和传统曝气生物滤池串联运行的方式,序批式曝气生物滤池(一级滤柱)在曝气量分别0.85L/(s·m2),1.27L/(s·m2),1.70L/(s·m2),2.12L/(s·m2)下运行,传统曝气生物滤池(二级滤柱)在曝气量分别为0.43L/(s·m2),0.85L/(s·m2),1.27L/(s·m2)下运行。试验结果表明:一级滤柱曝气量在1.70L/(s·m2)～2.12L/(s·m2)之间运行时,除磷效果好,出水TP含量在2.5mg/L以下,二级滤柱曝气量为0.85L/(s·m2)时,脱氮效果好,出水TN浓度为7.39mg/L,TN去除率达65.28%。采用间歇曝气/曝气生物滤池工艺能同时达到脱氮除磷的效果。     

加压生化—生物过滤法处理合成制药废水

应用加压生化与生物滤池相串联的生物处理工艺处理合成制药废水的试验表明：该工艺不但能够适应成份复杂多变以及污染物浓度较高、生物降解难度大的制药废水的处理，且效果显著。出水COD＜50mg／L，去除率为95％；BOD5＜10mg／L，去除率为97％；挥发酚的浓度＜0．1mg／L，去除率为99．9％；石油类的去除率为91％，各项水质指标均达到国家排放标准。     

MBR平板膜处理炼油污水试验研究

用平板膜好氧处理技术对炼油污水进行了处理量为180～250 L/h的侧线试验研究,试验结果表明:在进水COD为100～450 mg/L、氨氮20～90 mg/L、pH6～8的情况下,出水COD小于40 mg/L,出水氨氮小于6 mg/L,平均去除率90%以上。且该工艺的停留时间、出水指标和容积负荷均优于曝气生物滤池单元,从而证明膜生物工艺处理能力远超于现有曝气生物滤池工艺。     

低温条件下生物除磷系统的强化启动和运行

本文通过对比试验对冬季低温条件下生物除磷系统的启动和运行进行了研究，结果表明，低温条件下：(1)温度对生物除磷系统的影响是通过影响有机物的酸化水解而间接产生作用的；(2)通过人工投加HAc使污水中VFA≥80mg／L时，可以顺利启动生物除磷系统；(3)设置独立水解酸化池，可以提高生物除磷效果，在进水COD=150～300mg/L、磷酸盐=5mg／L时，出水磷酸盐≤1mg／L；(4)低温条件下按照水解-外循环ERP-SBR方式运行时，在磷酸盐浓度高达10mg／L的情况下仍能保证出水磷酸盐浓度≤0．5mg／L。     

改性竹炭生物滤池处理微污染原水的实验研究

以微污染原水中污染物质为去除目标,以廉价和资源丰富的竹炭为原料,通过微波辅助铁钴复合改性,制备了改性竹炭水处理材料,并应用于生物滤池中对微污染原水进行了实验研究。结果表明：在稳定运行条件下改性竹炭生物滤池对浊度、NH4＋－N及CODMn的平均去除率分别为84％、81％和74.5％,且随着运行时间的推移,改性竹炭生物滤池后期出水水质稳定：浊度＜1.0 NTU,NH4＋－N ＜0.5 mg／L,CODMn ＜1.0 mg／L。因此改性竹炭作为生物滤池填料应用于微污染原水处理是可行的。     

间歇时间对SBBR/BAF除磷影响

研究间歇曝气/曝气生物滤池脱氮除磷效果,确定其最佳间歇时间,为该种形式的曝气生物滤池高效运行提供依据。试验采用序批式曝气生物滤池SBBR和传统曝气生物滤池BAF串联运行的方式,序批式曝气生物滤池(一级滤柱)曝气时间与停曝气时间比为2h/1h、3h/2h和4h/3h下运行。试验结果表明:曝气与停曝气间歇时间在3h/2h运行时,除磷效果好,TP去除率为86.9%,出水TP平均浓度为0.92mg/L,COD去除率为88.42%,出水平均浓度30mg/L,均达到《城镇污水处理厂污染物排放标准》一级标准。采用SBBR-BAF工艺能同时达到脱氮除磷的效果,且系统在间歇时间为3h/2h下运行时,处理污水效能最大。     

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.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

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.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

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.