新型混凝剂处理印染废水的实验研究

采用自行制备的具有不同SiO2 :Al:Fe(摩尔比值 )和碱化度的两类新型无机高分子混凝剂聚硅酸氯化铝铁 (PSAFC)和聚硅酸硫酸铝铁 (PSAFS)各 7种 ,直接对印染废水进行处理。从中选出 2种混凝剂 ,考察了pH值、混凝剂投量等对混凝效果的影响 ,并对混凝处理后 ,印染废水出水中残留混凝剂主要成分Al、Fe、SiO2 的含量进行分析。实验结果表明 ,氯化物型 (PSAFC)和硫酸盐型 (PSAFS)混凝剂对印染废水的色度、浊度、CODCr均有良好的去除效果 ;总体而言 ,PSAFS的混凝效果略优于PSAFC ;混凝处理后印染废水出水中残留铝、铁、硅的含量均比较低 ;pH值和碱化度对混凝剂在水体中残留铝含量有影响     

制革含硫废水脱硫的预处理

通过催化氧化法和化学混凝法预处理制革含硫废水的脱硫探索试验,发现单一催化氧化法的曝气时间太长;单一化学混凝法,处理后出水不能符合后续生物处理含硫<40mg/L的容许浓度。为此,提出了催化剂投加量为100～200mg(Mn~(2+)/L(废水)、催化曝气1h、续加混凝剂聚合铁1.5mg/L的催化氧化—化学混凝法,处理含硫浓度100～200mg/L的废水,硫化物去除率达90％以上,出水含硫<40mg/L。     

曝气-混凝一体法去除碱性废水中砷的研究

采用曝气－混凝一体法处理碱性含砷废水。氧化方式研究表明,以曝气替代混凝机械搅拌过程,既起到氧化作用,又完成了混合作用,同时具有较好的处理效果;采用该法结合二次混凝工艺处理高浓度碱性含砷废水（砷浓度达414.94mg/L）,聚合铁为絮凝剂,总Fe/As＝3.0,砷去除率99.92％,出水中砷浓度0.33mg/L;在所选用的三种混凝剂中,聚合铁处理效果最佳。     

用聚合氯化铝铁混凝处理炼油废水的研究

考察了聚合硫酸铝铁、聚合氯化铝、聚丙烯酰胺和聚合氯化铝铁等混凝剂对炼油厂含油废水的混凝去除效果。结果表明，单独投加聚合硫酸铝铁、聚合氯化铝、聚丙烯酰胺三种混凝剂，对油及COD的混凝去除效果均不理想。投加聚合氯化铝铁对含油废水中的石油类物质及COD有显著的去除作用，对油及COD的去除率分别可达92．5％和78．1％。将聚合氯化铝铁与聚丙烯酰胺复后，对油对油及COD的混凝去除效果，发现对油及COD的去除率分别可达96．9％和75．3％。     

混凝法处理造纸废水的实验研究

利用以水玻璃、硫酸、硫酸铝和废铁屑为原料研制出的聚硅酸硫酸铝铁类混凝剂 ,在静态处理造纸废水的基础上 ,使用自行设计的动态模拟实验装置 ,对贵州省某造纸厂总排口废水进行混凝处理。在最佳水力条件下 ,造纸废水色度去除率达 96.9% ,CODCr去除率达 92 .5 % ,出水水质低于国家造纸工业污染物排放一级标准 ,说明复合型聚硅酸铝铁类混凝剂对造纸废水有着优异的去除效果     

聚合氯化铝及聚合氯化铝铁处理微污染地表水效果

选用两种无机高分子混凝剂聚合氯化铝(PAC)和聚合氯化铝铁(PAFC),与传统混凝剂Al2(SO4)3处理微污染地表水。以浊度和CODMn去除率为主要指标,考察投药量和pH对混凝效果的影响。通过考察沉淀时间对浊度去除效果的影响,结合实验现象,讨论三种混凝剂生成矾花的大小和沉降性能。结果发现,PAC和PAFC在5mg/L的投药量下可以取得较好的混凝效果,出水符合GB 5749-2006《生活饮用水卫生标准》。三种混凝剂的最佳pH为6,PAFC受pH影响较小,当pH为5～8时可取得较好的CODMn去除效果。PAFC生成的矾花体积较大,沉降性能较好,在实际应用中可缩短沉淀池的水力停留时间。     

紫外分光光度法在混凝处理二沉池出水中的应用

本研究根据二沉池出水特点，指出了以260nm紫外光(E260)评价处理二沉池出水的理论依据，然后确定了E260与COD的关系式为：E260=0．008COD 0．083，最后以E260为评价指标，比较了三种无机混凝剂在不同pH值条件下对城市二沉池出水的COD去除效果。并确定了最佳混凝剂为三氯化铁(FC)及混凝条件：pH4．5，投药量32mg(Fe^3 )／1。     

加碱混凝沉淀法去除蓝皮制革废水中Cr^3＋及COD的研究

取自扬州某外资皮革厂的蓝皮制革废水含有大量的Cr^3＋和COD。通过对该废水加各种碱剂调节其pH值至8．3～8．5，均可将Cr^3＋去除90％以上，且对COD也有一定的去除效果。再对该废水加碱的同时试采用几种混凝剂进行混凝，Cr^3＋和COD的去除率都得到提高。研究表明：通过加碱混凝能取得更好的去除效果，PAC／PAM是最佳混凝剂，最佳投药量为0．4g／L，Cr^3＋可降到国家标准以下。     

酸浸粉煤灰混凝法处理制革废水的研究

笔者研究了在热电厂粉煤灰中加入少量的鼓风炉铁泥和适量的助溶剂HS,在加热条件下用稀硫酸搅拌浸取2h后,制得集物理吸附和化学混凝为一体的混凝剂。这种混凝剂与聚硅酸铝铁(PSAF)絮凝剂配合处理COD为1500～2000mg/L制革废水,SS,COD,硫化物和铬的去除率分别为95%,93%,92%和88%。该法的显著特点是混凝沉降速度快,污泥体积小,处理废水费用低,此外还探讨了酸浸粉煤灰混凝剂对制革废水的混凝沉降机理。      

梯级混凝技术在造纸废水处理中的应用

选取聚合氯化铝(PAC)和聚丙烯酰胺(PAM)作混凝剂对速生材造纸中段废水进行了梯级混凝(即混凝及其污泥回流)处理,考查了pH值、PAC投加量、污泥回流量等因素对处理效果的影响。结果表明,当废水pH值为6.5～8.2、PAC用量3 mL/L、污泥回流量为40%～60%时,实验效果明显优于传统混凝方式,COD由400 mg/L降至100 mg/L左右,去除率达75%。出水pH值为7.5～8.2,符合国家排放标准,并满足造纸回用水要求。     

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.     

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.     

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.     

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.     

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

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