复合混凝剂处理印染废水

为了处理高浓度、高色度、高COD的印染废水，利用硫酸亚铁、工业废酸和金属下脚料自行配制了复合混凝剂，并将其与聚合双酸铝铁、聚合氯化铝铁、硫酸亚铁对印染废水的混凝效果进行对比。研究表明，复合混凝剂处理印染废水具有成本低、效果好的特点。当硫酸亚铁的投加量为200mg/L，复合混凝剂的投加量为1280mg／L，PAM的用量为2mg／L时，脱色率达94．9％，COD去除率达78．1％，悬浮固体（SS）去除率达90．9％。     

混凝剂FAS的制备及性能研究

报道利用铜矿渣制取固体混凝剂ＦＡＳ。实验表明,该混凝剂具有优良的除蚀、除色、除ＣＯＤ、除硫性能,尤其对采用常规混凝剂难以除去的亲水性染料,ＦＡＳ有独特的去除效率。对各种模拟废水和实际废水,ＦＡＳ的脱色率为９５％,对ＣＯＤ的去除率则在９０％以上。本文还对ＦＡＳ的混凝脱色机理进行了初步的探讨。     

复配混凝剂处理染料废水的研究

以COD为288mg／L,色度为25000倍的配制酸性大红GR染料废水为对象,在研究常用混凝剂处理的基础上,配制了FeSO4——MgSO4-PAM复配混凝剂,并通过实验优化了操作条件。结果表明,复配混凝剂在较少的投加量下,即可同时达到较高的脱色率与COD去除率,处理效果明显优于单一混凝剂。当脱色率达90．9％,COD去除率达74．1％时,复配混凝剂总药剂费用仅为0．94元／吨废水,在经济性和处理效果上均是可行的。     

酸改性粉煤灰处理焦化废水的工艺研究

研究了粉煤灰与少量的硫酸烧渣和适量的固体NaCl混合 ,将混合物在加热条件下用稀硫酸处理 ,制得集物理吸附和化学混凝为一体的混凝剂。这种混凝剂与无机高分子絮凝剂PSA配合用于焦化废水的处理 ,SS、CODCr、色度和酚的去除率分别为 95 %、86 %、96 %和 92 %。混凝沉降速度快 ,污泥体积小 ,处理费用低 ,结合显微照片探讨了酸浸粉煤灰混凝剂对含酚废水的混凝沉降机理     

硼泥复合混凝剂处理采油井管洗涤废水的研究

探讨了利用废渣生产的硼泥复合混凝剂处理采油井管洗涤废水，以及pH值，混凝剂的投加量，搅拌速度，搅拌时间，沉降时间和温度处理效果的影响，当废水的含油量在8500mg/L左右时，投药量为2000mg/L,最佳值范围为4．5－8．5，油COD和SS的去除率分别大于84％，825，98％，沉降时间为35min，搅拌速度，搅拌时间，温度对油，COD和SS的去除率无显著影响，若经双层滤料过滤法或生化法的二级处理，出水达到国家一级排放标准。     

含硫化黑染料废水混凝脱色的试验研究

文章针对含硫化黑染料废水的色度大、成分复杂的特点,采用混凝法对染料废水的脱色问题进行了研究。研究表明使用无机混凝剂氯化铁和硫酸铝处理含硫化黑染料废水时,铁盐的脱色效果要明显好于铝盐,当水样呈现中性或偏碱性,氯化铁的投药量为0．28g／l,染料初始浓度为250mg／l时,处理效果最佳,脱色率达到96．8％。同时还探讨了将有机混凝剂PAM与氯化铁进行复配处理含硫化黑染料废水的效果。结果表明当PAM投加量为0．12g／l,氯化铁的投加量为0．28g／l时,复合混凝剂的脱色效果最好,脱色率高达98．8％。     

改性铁法处理印染废水

通过对铁屑进行改性,并辅以其它活性材料构成填料塔对印染废水进行处理。结果表明改性铁法与传统的铁屑固定氏法相比较,对可溶性染料的处理效果,二者相近;对不溶性染料本法的脱色率和COD去除率比传统铁屑法提高20％～30％,基本上解决了传统铁屑法不容易处理不溶性染料的难题。综合考虑COD去除率、脱色率两方面因素,选择pH值5～6,接触时间13～15min为最佳。     

高浓度服装水洗废水的混凝处理研究

采用化学混凝法,以PAC为混凝剂,PAM为助凝剂,对高浓度服装水洗废水进行处理研究。考察了溶液的pH值、PAC的投加量、PAM的用量等因素对脱色率及COD去除率的影响,得到最佳工艺条件为:pH为8.0左右,PAC投加量为25mL/L(废水),PAM的投加量为1.0mL/L(废水)。在此条件下,服装水洗废水的脱色率为73.1%,COD的去除率为72.1%。     

铁系混凝剂对大红染料废水处理效果研究

采用Fe(NO)3.39H2O和FeSO.47H2O混凝剂处理模拟大红染料废水,通过改变各药剂投加量及废水pH值,考察其对废水COD和色度的去除效果。实验结果表明:两种混凝剂在处理大红染料废水中都表现出了较好的脱色性能,而Fe(NO3)3.9H2O的去除性能较FeSO.47H2O更为优越。Fe(NO)3.39H2O对染料废水的脱色作用十分显著,所有的脱色率都在86%以上。当投加量为0.18 g时,脱色率达最大值93.3%;当投加量为0.24 g时,COD去除率为63.6%。FeSO.47H2O对废水色度的去除效果好于COD的去除。其最佳投加量为1.5 g,此时,脱色率达82.4%;当投加量为0.9 g时,COD去除率为51.8%。Fe(NO)3.39H2O在pH为5.0~9.0之间处理效果都较好,当pH=8时,其脱色率最高,为93.4%;FeSO.47H2O在pH为6.0~8.0之间最佳,当pH=8时,脱色率最高为83.2%。     

毛发载体生物膜法对印染、化工废水脱色处理的试验研究

利用经特定脱脂处理后的毛发作载体,固定脱色混合菌。依赖毛发自身营养,不需外加营养物质,对印染和化工有色废水作脱色处理。试验研究结果表明,在一定pH和温度下,废水脱色率可稳定在85％以上;在低温或大于32℃时,仍可保持较高的脱色率,并可同时去除废水中的硫化物、氰化物、酚类等有毒有害污染物,其去除率>80％。     

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.     

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.     

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.     

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.     

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.