BAF+过滤在炼油污水回用中的应用

采用BAF＋过滤处理炼油污水，CODcr石油类、氨氮、SS去除率可以达到51．8％、62．8％、75％、100％，在BAF进水指标符合GB8978—1996污水综合排放标准一级标准，处理后出水指标可以达到CODcr≯55mg／L，Oil≯2m/L，NH3-N≯5mg／L,SS≯1mg／L，达到中石化循环水补充水标准。     

改性纤维球处理炼油废水的应用研究

通过用改性纤维球处理炼油废水的试验,对纤维球过滤技术的处理效果和反冲洗特性进行了详细的研究,试验结果表明,炼油废水经处理后,出水中油的含量小于4 mg/L、悬浮物含量小于6 mg/L,出水可达标排放,并且经过改性后的纤维球在含油废水处理中可以通过反冲洗再生并重复使用.     

精制棉废水处理工程实践

针对在生产精制棉中产生的碱性黑液，采用吸附-厌氧-好氧-混凝处理工艺。运行结果表明，在进水CODcr≥6800mg／L，色度≥4000倍时，处理后出水CODcr≤100mg／L，色度≤50倍，达到《污水综合排放标准》(GB8978-1996)一级标准。该工艺采用生物吸附作为预处理，很大程度上降低了运行费用。     

凤眼莲生态工程在炼油废水深度处理中的应用研究

在炼油废水氧化塘中建设凤眼莲生态工程。该工程较显著地提高出水水质及透明度，对其中污染物质均有不同程度的去除能力。在炼油废水氧化塘中实施凤眼莲生态工程的最佳运行控制条件为：６５ｍｇ／Ｌ≤ＣＯＤ≤１３１ｍｇ／Ｌ，最高临界ＣＯＤ为２６３ｍｇ／Ｌ，故凤眼莲生态工程适用于炼油废水的深度处理。对凤眼莲去除炼油废水中污染物的机理进行了初步探讨。     

炼油污水深度处理回用中试研究

通过二期炼油污水深度处理中试研究表明，以炼油企业二级处理达标排放污水为处理对象，当本工艺处理水量0．5m3／h、水力停留时间1．49h，污水中COD、氨氮、石油类的浓度变化分别为44．07～102．13mg／L、28．37～50．0lmg／L、4．10～6．77mg／L时，平均去除率分别达到94％、96．1％、91.9％，出水符合循环水补充水水质要求；5．5h抗冲击实验结果显示，本工艺抗冲击能力优良。     

热轧浊循环水处理的中试研究

应用处理量8m3/h的压紧式改性纤维球压力过滤器,对某钢铁厂热轧浊循环水进行处理。结果表明,采用纤维球过滤能有效的去除热轧浊循环水中的油类和悬浮物(SS),过滤后的出水中油含量能降低到1.8~4.5mg/L,去除率达到84.5%,悬浮物(SS)最高9.5mg/L,平均5.04mg/L,去除率达到88.77%,满足该厂要求热轧循环用水油含量≤5mg/L,悬浮物≤10mg/L的要求。     

AADR-A/O工艺处理头孢类制药废水

本文论述了AADR—A／O工艺处理头孢类制药废水，研究了该工艺的设计、运行及工艺特点。经运行结果表明，当高浓度废水浓度CODCr为28864～34623mg／L，BOD5 12438～15790mg／L，pH3．9～4．5，SS≤110mg／L，处理水量为96～210m^3／d；低浓度废水CODCr为225～350mg／L，BOD5 106～142mg／L，pH7．0～7．5，SS≤100mg／L，处理水量为1250～1502m^3／d时，处理后出水CODCr≤150mg／L，BOD5≤60mg／L，SS≤100mg／L，NH4-N≤25mg／L，达到了《污水综合排放标准》(GB8978—1996)中的二级标准。对该工艺实际运行成本考核得知：运行处理费用为2．33元／m^3水。     

物化／两级好氧生化法处理皮革废水

广州市新星皮革厂污水处理站规模为200m^3／d，采用物化／两级好氧处理工艺，在进水CODCT为2500～3000mg／L。BOD5为1200～1500mg／L，SS为320～600mg／L，pH为6～10，Cr总≤52．7mg／L，Cr^6 ≤5．6mg/L色度约为240倍的条件下，处理后出水水质为CODCT≤80mg／L，BOD≤30mg／L，SS≤70mg/L，pH为6～9，Cr总≤1．2mg/L，Cr^6 ≤0.4mg／L，色度≤40倍。达到了《广州市污水排放标准》(DB44137-90)新扩改一级标准。     

大型啤酒企业废水处理工程的设计与运行

采用酸化-生物接触氧化工艺处理大型啤酒企业生产废水。工程运行表明在进水SS、CODCr、BOD5平均浓度分别为516mg／L、572mg／L、288mg／L的条件下，排出水的SS、CODCr、BOD5平均浓度分别为46mg／L、36mg／L、6．2mg／L，处理后水质达到《污水综合排放标准》(GB8978-1996)二级排放标准。本工艺具有运行稳定可靠，容积负荷高，处理效果好，运行费用低，污泥产量小；不发生污泥膨胀等特点。     

沉灰池扩建工程设计与运行效果

本对新建75t／h煤粉、蔗糠两用锅炉．并配套麻石水膜除尘器，在利用原有沉淀池的基础上，设计串联370m62平流式沉灰池两台，废水处理能力提高了一倍，循环水pH平均为6．57．COD平均为43．53mg／L，SS平均为158．S4mg／L．冲灰水无须加入石灰和絮凝剂，经沉淀处理后循环使用，取得较好的经济效益．     

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.     

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

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Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

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.