混凝法处理肉联厂废水

聚合氯化硫酸铝铁和聚合氯化硫酸铝混凝剂处理ＣＯＤ为１５００－２０００ｍｇ／Ｌ肉联厂废水的最佳工艺条件：ＰＨ范围为６．２－８．５搅拌速度为１６０转／分；搅拌时间１５ｍｉｎ，一次处理混凝剂投加量为２００ｍｇ／Ｌ，沉降时间３００ｍｉｎ，ＣＯＤ去除率在９０％以上，达到国家二级排放标准。若分二次混凝处理效果更佳，一次混凝处理后，经无烟煤－石英砂滤柱过滤，出水的ＰＨ、ＳＳ、ＣＯＤ均达到国家一级排放标准。     

乳化液的破乳与可生化性研究

根据混凝破乳处理乳化废液的实验参数，考察了混凝出水的可生化性。结果表明，ＰＢＴ混凝剂，具有良好的破乳效果，ＣＯＤｃｒ和油的平均去除率，分别达９０％与９９％以上，混凝出水ＢＯＤ５／ＣＯＤｃｒ可达０．４２－０．４６；间歇曝气实验及呼吸耗氧速率曲线表明，ＰＢＴ混凝出水，宜进行生化处理。     

废纸脱墨废水混凝性能研究

对脱墨废水混凝处理的混凝剂和助凝剂的种类和用量进行了试验．结果表明：ＰＩＯ较硫酸铝混凝性能好，添加少量ＰＡＭ助凝剂有利于絮凝物的沉降，脱墨废水中ＳＳ、ＣＯＤＣｒ和ＢＯＤ５的去除率分别达到８５．４％，７８．２％和７１．７％．     

炼铁厂煤气洗涤废水净化处理技术与实践

介绍了采用混凝沉淀法———加注高分子混凝剂聚丙烯酰胺处理煤气洗涤水，使水中污染因子ＳＳ去除率达８４５％以上；ＣＯＤＣｒ去除率达６１８％以上；氰化物和挥发酚也有不同程度的削减，实现了废水循环利用。     

混凝氧化吸附法处理精研精抛清洗废液

采用混凝氧化吸附法处理精研精抛清洗废液，对６种混凝剂的ＰＨ值、投加量及氧化剂Ｈ２Ｏ２的投加量进行了筛选，同时简单地分析了混凝氧化反应机理，经混凝氧化处理后，ＣＯＤ值由１２０００ｍｇ／Ｌ降至５００ｍｇ／Ｌ左右，ＣＯＤ去除率达９５％；最后进行活性碳吸附，ＣＯＤ值达到国家排放标准。     

硫酸亚铁酸洗废液在制革废水处理中的应用

用混凝沉淀－微滤工艺对制革废水进行试验研究。结果表明,用含硫酸亚铁酸洗废液作混凝剂是行之有效的,经此工艺处理后,ＣＯＤ、ＢＯＤ_５、ＳＳ和色度的去除率分别为８０．４％、８７．２％、８８．６％和９１．７％,处理后废水水质达到排放标准,而且其中５０％回用于生产。此工艺具有很好的应用前景,尤其适合北方寒冷地区。     

植物油精炼废水处理工艺研究

采用ＰＦＣ物化混凝破乳及ＰＡＣ生物处理技术，对炼油、皂脚混合废水处理工艺进行了研究。结果表明，该废水在ＰＨ为９－１３．ＣＯＤＣＲ为１万－１０ｍｇ／Ｌ时，采用ＰＦＳ混凝破乳，ＰＡＣ生物处理后，ＣＯＤＣＲ和ＢＯＤ５总去除率分别为９９．６％和９９．４％。废水经过处理，含渍量，ＣＯＤＣＲ、ＢＯＤ５、色度，ＰＨ等指标中达标排放。     

混凝氧化法处理精研精抛清洗废液

采用混凝、氧化的方法对精研精抛清洗废液进行处理，对絮凝过程中所用的６种混凝剂的投加量ｐＨ值和氧化过程中的氧化试剂Ｈ２Ｏ２的投加量分别进行了筛选，同时简单地分析了反应机理．经混凝氧化处理后，ＣＯＤ值由１２００ｍｇ／ｍＬ降至５００ｍｇ／ｍＬ左右，ＣＯＤ去除率达９５％；最后进行活性炭吸附，ＣＯＤ值达到国家排放标准．     

混凝——接触氧化处理毛纺染色废水

采用混凝－－接触氧化法处理毛纺染色废水，ＣＯＤ平均去除率为７６．７％，色度平均去除率为９５．７％的效果。各项指标均符合排放要求。     

洁霉素生产废水处理的研究

采用水解（酸化）－二段投菌生物接触氧化－混凝工艺处理浓度洁霉素废水,中试结果表明：进水ＣＯＤ浓度为３５００－５０００ｍｇ／Ｌ范围时,出水ＣＯＤ平均去除率大于９５％,进水ＢＯＤ浓度为１０００－１５００ｍｇ／Ｌ范围时,出水ＢＯＤ平均去除率大于９６％,各项指标达到国家ＧＢ８９７８－８８排放标准。     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

Effect of sorbed and desorbed Zn(Ⅱ) on the growth of a green alga (Chlorella pyrenoidosa)

Toxic effect of Zn(Ⅱ) on a green alga (Chlorella pyrenoidasa) in the presence of sepiolite and kaolinite was investigated.The Zn-free clays were found to have a negative impact on the growth of C.pyrenoidosa in comparison with control samples (without adding any clay or Zn(Ⅱ)).When Zn(Ⅱ) was added,the algae in the presence of clays could be better survived than the control samples,which was actually caused by a decrease in Zn(Ⅱ) concentration in the solution owing to the adsorption of Zn(Ⅱ) on the clays.When the solution system was diluted,the growth of algae could be further inhibited as compared to that in a system which had the same initial Zn(Ⅱ) concentration as in the diluted system.This in fact resulted from desorption of Zn(Ⅱ) from the zinc-contaminated clays,although the effect varied according to the different desorption capabilities of sepiolite and kaolinite.Therefore the adsorption and desorption processes of Zn(Ⅱ) played an important part in its toxicity,and adsorption and desorption of pollutants on soils/sediments should be well considered in natural eco-environmental systems before their risk of toxicity to aquatic organisms was assessed objectively.