高铁酸盐氧化絮凝去除水中腐殖质的研究

研究了高铁酸盐对饮用水中富里酸（ＦＡ）的去除性能与作用条件，考察了高铁酸盐单独氧化、氧化絮凝和与聚合氯化铝联合应用的除ＦＡ效果。结果表明，当高铁酸钾与ＦＡ的质量比为１２时，高铁酸盐氧化可以去除水中９０％以上的ＦＡ，在浑浊水中高铁酸盐具有氧化和絮凝的双重作用效能，同样高铁酸盐投加量下，可将９５％以上的ＦＡ去除。采取高铁酸盐与聚合铝联用可显提高对ＦＡ的去除效果。     

BF4-废水水解法实验

常温下用水解法处理ＢＦ４废水．实验采用铝盐作主水解剂，试剂Ａ作助水解剂，ｐＨ值小于３，在常温条件下实现了对ＢＦ４的高效水解．研究结果表明，ＢＦ４∶Ａｌ３＋∶Ａ的质量比为１∶０．８∶０．１，水解时间６～３ｈ，水解率达到９９．５％以上．使用助水解剂Ａ，缩短了水解时间，减少了铝盐用量，对高浓度的ＢＦ４废水效果尤为显著，水解时间可缩短一半，主水解剂用量可减少１／５，处理后出水中的ＢＦ４含量可降到１０ｍｇ／Ｌ以下．     

铝和铁共聚物的组成与结晶形貌

通过扫描电镜对铝，铁均聚物与共聚物样品的观察，不同Ａｌ／Ｆｅ的能谱点测定，其晶形貌象进行了比较，并探讨其共聚合作用的机理，为深入研究铝，铁无机共聚合物特性及絮凝效能提供了基础依据。     

颗粒物悬浮体系中聚合铝凝聚絮凝形态表征 (Ⅰ):Al-Feron法的应用研究

应用Ａｌ－Ｆｅｒｒｏｎ法于悬浮体系中聚合铝的形态分布表征，对其中的主要影响因素进行探讨，就不同碱化度聚合铝的形态分析进行实例研究．结果表明，混合方式对Ａｌ－Ｆｅｒｏｎ法的应用具有一定的影响作用．比色管混合测得Ａｌａ为２１．５４％，低于磁力搅拌方式结果（２４．５２％，２５．２２％，２５．０６％）．应用磁力搅拌方式可以获取较好的重复性与更多初期反应信息．颗粒物的存在对反应的影响主要取决于其浓度与粒度分布，成一定线性关系，可以从中加以扣除．在本实验范围内因其溶解所产生的影响可以忽略不计．对多个碱化度聚合铝的实例研究表明，Ａｌ－Ｆｅｒｏｎ法完全适用于颗粒物悬浮体系中的形态分布表征     

中和絮凝法去除矿坑废水中Mn,Fe的研究

采用石灰乳中和，聚合氯化铝铁（ＰＡＦＣ）絮凝沉降方法对煤矿矿坑废水中的Ｍｎ，Ｆｅ进行了去除试验研究，在选定的操作条件下，处理后，矿坑废水中的Ｍｎ的去除率≥９７％，Ｆｅ的去除率≥８６％，ＳＳ的去除率≥９５％，通过对中和吸附，絮凝沉降ＭｎＦｅ的机理分析，认为ＰＡＦＣ在ｐＨ〈９．０时ζ电位由正变负的电中和作用是确保处理后水体ｐＨ≤９．０；（Ｍｎ＾２＋）≤０．１ｍｇ／Ｌ；（Ｆｅ＾３＋）≤０．３ｍｇ／Ｌ的前     

羟基聚合氯化铝铁溶液的形态分布特征

采用改进的Ａｌ＝Ｆｅ－Ｆｅｒｒｏｎ逐时络合比色法定量研究了ＨＰＡＦＣ的形态分布，结合酸解聚实验和酸反一实验结果，综述了其形态分布特征，在碱化度Ｂ为１．０～２．０内，ｎＡｌ／ｎＦｅ＝９：１时，单体和二聚体（Ａｌ＋Ｆｅ）达２０％～６０％，ｎＡｌ／ｎＦｅ＝５：５时达３０％～５０％，ｎＡｌ／ｎＦｅ＝９：１时，中间多在络合物（Ａｌ／ｎＦｅ＝５：５时达５％～２０％，ｎＡｌ／ｎＦｅ＝９：１时，溶胶（Ａｌ＋Ｆｅ）     

酸性溶液中铝-氟反应动力学

研究了酸性溶液中铝氟反应的动力学，结果表明，铝氟之间的反应速率随温度和ｐＨ的升高而增加．低ｐＨ下以Ａｌ３＋＋Ｆ－＝ＡｌＦ２＋反应为主，较高ｐＨ下由于ＡｌＯＨ２＋参与反应及ＯＨ－的催化作用，反应速率加快．在铝的浓度比氟过量１０倍的情况下，铝氟之间的反应可以用一级反应动力学方程来拟合，即为假一级反应．当ｐＨ＜３８时，柠檬酸和草酸的存在使反应速度加快，而当ｐＨ＞３８时，有机酸使铝氟反应速度变慢．有机酸在不同的ｐＨ下存在不同的作用机制．     

天然高分子改性阳离子絮凝剂的合成及其性能与机理的研究

以天然高分子物Ｆ６９１粉为原料，合成了一种新型阳离子絮凝剂ＦＮＱＤ。研究表明：在ＮａＯＨ／Ｆ６９１质量比１、穹剂／Ｆ６９１质量比１．５，反应温度５０℃、反应时间３ｈ条件下，ＦＮＱＤ具有优导的絮凝性能。当ＰＨ＝７、投加量３ｍｇ／１时，ＦＮＱＣＤ对市内悬浊度去除率〉９５％，絮凝性能明显优于ＰＡＭ－Ｃ。机理表明ＦＮＱＤ与胶体颗粒间的镶嵌式引力和ＦＮＱＤ分子链的半刚性结构是ＦＮＱＤ具有优异的絮凝性能和良好     

营养盐对三角褐指藻脂肪酸含量与百分组成的影响

通过对三角褐指藻分别大硅不足、维生素不足、氮不忠 、磷不足等不同营养盐条件下增养的对比试验。发现随氮营养盐不足加剧,ＴＰＵＦＡ含量大幅度下降,由对照组４２．１３％降至２９．８６％（５０％Ｎ）和２０．１７％（５％Ｎ）,ＥＰＡ含量则由对照组２１．４１％降至１２．９４％（５０Ｎ）和１０．５４％（５％Ｎ）。磷不足能导至ＴＦＡ的增加和积累,但ＴＰＵＦＡ（包括ＥＰＡ）占总脂肪酸的百分比却呈现下降趋势。硅不足和     

聚合铝有机高分子稳定增效剂

本文试验了有机高分子物质ＰＥＯ、ＰＡＭ对液体ＰＡＣ的稳定性和絮凝性能的影响，结果表明，在投加量适当的情况下，ＰＥＯ能提高液体ＰＡＣ的稳定性和絮凝性能，而ＰＡＭ对ＰＡＣ的稳定性影响不大，但能增强其絮凝能力。     

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.     

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

ＲｅｍｏｖａｌｏｆｈｅａｖｙｍｅｔａｌｓｆｒｏｍｓｅｗａｇｅｓｌｕｄｇｅｂｙｌｏｗｃｏｓｔｉｎｇｃｈｅｍｉｃａｌｍｅｔｈｏｄａｎｄｒｅｃｙｃｌｉｎｇｉｎａｇｒｉｃｕｌｔｕｒｅＷｕＱｉｔａｎｇ，ＮｙｉｒａｎｄｅｇｅＰａｓｃａｓｉｅ，ＭｏＣｅｈｕｉＦ...     

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.     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.     

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.     

Seed selections for crystallization of calcium phosphate for phosphorus recovery

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.