废FCC催化剂对水中铅离子的连续吸附及脱附

通过测定吸附等温线，考察了Ｐｂ２＋在废ＦＣＣ（流化催化裂化）催化剂上的吸附性能及规律，结果表明，Ｐｂ２＋在废ＦＣＣ催化剂上的吸附规律可用Ｌａｎｇｍｕｉｒ和Ｆｒｕｎｄｌｉｃｈ模式描述，吸附呈单分子层形式且容易进行。又通过填充床吸附试验，对Ｐｂ２＋的连续吸附及脱附情形作了考察。结果表明，在温度为１５℃、ｐＨ为５．１３、过柱速率为３．０ｍＬ／ｍｉｎ、径高比为２．２５．０条件下，吸附柱具备适宜的生产周期，连续吸附操作可行，柱效率可达７５．９％；在温度为１５℃、采用２ｍｏｌ／Ｌ稀盐酸作脱附剂，过柱速率为５．０ｍＬ／ｍｉｎ的条件下，吸附剂易于脱附再生，脱附效率可达７８．１％     

海藻生物吸附废水中铅、铜和镉的研究

对几种大型海藻作国吸附剂，吸附重金属废水中Ｐｂ＾＠＋、Ｃｕ＾２＋、Ｃｄ＾２＋的吸附容量和吸附速度进行了研究，得出了它们对Ｐｂ＾２＋、Ｃｕ＾２＋、Ｃｄ＾２＝平衡吸附的等温曲线。实验表明，海藻的最大吸附容量在０．８～１．６ｍｍｏｌ／ｇ（干重）之间，吸附容量比其他种类的生物体高得多。吸附速度较快，１０ｍｉｎ内，重金属从溶液中的去除率可达到９０％。实验结果还表明，大型海藻适合于发展成为高效的生物吸附材料用     

空气中硫化物的间接光度法测定

基于Ｐｂ＾２＋与Ｓ＾２－形成难溶的Ｐｂｓ，过量的Ｐｂ＾２＋用四（４－甲基－３－磺酸苯基）卟啉［Ｔ（４－Ｍｐ）Ｐｓ４］光度法测定的原理，采用［Ｐｂ－Ｔ（４－Ｍｐ）Ｐｓ４］光度法间接测定空气中的硫化物。讨论了酸度对Ｐｂｓ形成的影响；Ｈ２Ｓ吸收液的选择：共存离子的影响等。方法的线性范围为０￣０．３２ｍｇ／Ｌ；最低检出浓度为０．０２ｍｇ／Ｌ；精密度试验的变异系数为４．０％；回收率为９６．０％￣１０７．６％     

橡碗单宁去除水中有毒重金属离子的研究

研究了用橡碗单宁处理Ｐｂ＾２＋，Ｃｄ＾２＋，Ｃｒ＾３＋，Ｚｎ＾２＋，Ｍｎ＾２＋，Ｆｅ＾２＋六种重金属离子的最佳条件。结果表明，在中性或微碱性条件下，几种金属离子的冒险 除率分别可达８０．６％、９２．２％、８５．３％、９１．４％、８５．０％，、８６．０％。探讨了橡碗单达絮凝的机理。     

氨基酸型螯合树脂的合成及其吸附性能

以三乙烯四胺，环氧氯丙烷和氯乙酸为原料，合成了氨基酸结构的螯合树脂，并研究了Ｃｕ＾２＋，Ｐｂ＾２＋，Ｎｉ＾２＋，Ｚｎ＾２＋的吸附性能。结果表明，该树脂对Ｃｕ＾２＋，Ｐｂ＾２＋，Ｐｂ＾２＋，Ｎｉ＾２＋比对Ｚｎ＾２＋具有良好的吸附性能，其吸附量可达１．４０，，１．３９，１．２０及０．４ｍｏｌ／ｇ。     

膨润土对Pb2+的吸附性能及影响吸附的主要因素

探讨了天然膨润土对Ｐｂ＾２＋的吸附性能及其主要影响因素，天然膨润土对Ｐｂ＾２＋的吸附能力很强，当Ｐｂ＾２＋的浓度小于２０ｍｇ／Ｌ时，去除率可达９９％以上，吸附受溶液ＰＨ、吸附剂用量以及振荡时间的影响，但溶液中存在的有机污染物不影响膨润土对Ｐｂ＾２＋的吸附。     

橡■单宁去除水中有毒重金属离子的研究

研究了用橡单宁处理Ｐｂ２＋、Ｃｄ２＋、Ｃｒ３＋、Ｚｎ２＋、Ｍｎ２＋、Ｆｅ２＋六种重金属离子的最佳条件。结果表明，在中性或微碱性条件下，几种金属离子的最佳去除率分别可达８０６％、９２２％、８５３％、９１４％、８５０％、８６０％。探讨了橡单宁絮凝的机理。     

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     

金鱼(Carassius auratus L.)对水中游离态铅的吸收积累及鳃分泌粘液的自身保护作用

研究了金鱼（ Ｃａｒａｓｓｉｕｓａｕｒａｔｕｓ Ｌ．） 在铅暴露实验中的铅吸收过程及鱼鳃分泌物的自身保护作用、水相Ｐｂ２＋ 的鳃吸收机理以及分泌粘液对铅的络合作用．结果表明，金鱼因铅暴露导致粘液分泌量增加．结合到鳃上的铅与水相Ｐｂ２＋ 活度关系可用Ｌａｎｇｍｕｉｒ 吸附等温式表述．据此估算的最大结合量为０－９４２４ ｍ ｍｏｌ／ｋｇ（干重） ．非常接近１ 的Ｈｉｌｌ 常数（１－０１２）说明金鱼鳃上仅有一种类型的Ｐｂ２＋ 结合位点．平均每尾金鱼鳃上Ｐｂ２＋ 的结合位点数达１－６２ ×１０－ ５ ｍ ｍｏｌ，结合的条件稳定常数（ｌｏｇ ＫＰｂ鳃） 为４－８ ．血液铅含量与鳃铅含量间呈显著线性关系．金鱼吸收Ｐｂ２＋ 的主要过程为：Ｐｂ２＋ 结合到鳃上，其后被动扩散或载体转运穿过鳃上皮，进入血液循环．     

非活性黑根霉菌对废水中重金属离子的吸附

为探讨发酵工业中废弃的菌丝体黑根霉菌（Ｒｈｉｚｏｐｕｓｎｉｇｒｉｃａｎｓ）对水中重金属离子的吸附特性,考察ｐＨ、浓度、共存离子等因素对吸附能力的影响,进行了实验室吸附试验,绘制出吸附等温线,并由Ｌａｎｇｍｕｉｒ曲线和Ｆｒｅｕｎｄｌｉｃｈ曲线求出相应参数。对化学改性前后的黑根霉进行了吸附对比。初步分析了吸附机理。结果表明,黑根霉在ｐＨ＝３—６．５范围内,对Ｐｂ２＋、Ｃｕ２＋、Ｍｎ２＋、Ｃｒ（ＶＩ）几种主要重金属离子都有吸附作用,其中吸附Ｐｂ２＋能力最高,饱和吸附量可达８８ｍｇ／ｇ。经化学改性的黑根霉可不同程度地提高吸附能力。用０．５ｍｏｌ／ＬＨＣＩ和ＮａｏＨ可以洗脱和再生。     

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.     

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.