真空膜蒸馏处理循环冷却水的试验研究

基于提高循环冷却水的处理效率,并探寻新的电去离子预处理工艺,利用自制中空纤维膜组件,考察了真空膜蒸馏过程参数对产水水质的影响.结果表明,在试验范围内,料液流量(7.21～18.98 L/h)、热侧温度(52℃～73℃)、冷侧真空度(0.055～0.087MPa)对产水水质影响不大,电导率在5μS/cm以下,总硬度小于1 mg/L(以GaCO3计),UV254在0.02～0.04之间,TOC在0.05～0.5 mg/L之间,去除率分别达到99.8％、99.85％、93.71％、99.65％,可以达到电去离子的进水水质要求;预软化可以提高出水水质;浓缩倍数增大到20倍,电导率由1.72 μS/cm上升到3.73 μS/cm,Ca2+浓度、UV254、TOC等指标变化不大,采用真空膜蒸馏可望实现循环冷却水的零排放.     

洞庭湖典型水域表层沉积物中重金属空间分布特征及其潜在生态风险评价

基于2007—2012年连续对洞庭湖湘江入湖口至出湖口水域5个采样点——S1(樟树港)、S2(虞公庙)、S3(鹿角)、S4(君山)和S5(洞庭湖出口)表层沉积物中Cd、Hg、As、Cu、Pb、Cr和Zn 7种重金属质量分数分析,对该典型水域表层沉积物中重金属的空间分布特征进行了探讨,并采用潜在生态危害指数法对其生态风险进行评价. 结果表明:表层沉积物中w(Cd)、w(Hg)、w(As)、w(Cu)、w(Pb)、w(Cr)和w(Zn)分别为0.54~79.90、0.046~0.712、15.2~289.0、29.0~217.0、6.0~246.0、65.4~269.0和41.4~632.0 mg/kg,w(Cd)、w(Hg)、w(As)、w(Cu)、w(Pb)和w(Zn)沿程总体呈下降趋势,w(Cr)沿程变化较小;Cd具有很高生态风险,Hg具有中等生态风险,其余污染物具有低生态风险,不同污染物生态风险的大小顺序为Cd＞Hg＞As＞Pb＞Cu＞Cr＞Zn,各采样点的RI(潜在生态危害指数)为115.51~1 000.09,平均值为373.30,研究区域重金属总体具有高生态风险,其中S1采样点具有很高生态风险,不同采样点表层沉积物中重金属生态风险的大小顺序为S1＞S2＞S5＞S4＞S3;除Cr外,Cd、Hg、As、Cu、Pb和Zn主要来源于湘江,Cd和Hg是主要风险污染物,其中Cd为首要污染物,因此湘江重金属污染治理应以Cd为重点.      

膜蒸馏去除水中Cr(Ⅵ)研究

构建PVDF中空纤维疏水膜为膜组件的膜蒸馏装置对100 mg/L的实验室Cr(VI)废水进行处理。研究了不同温差条件下膜通量变化情况、膜通量及产水电导率随时间变化情况、进出水Cr(VI)浓度变化情况及长周期运行条件下的膜通量变化情况。实验结果表明:随着温差的增大,膜通量保持增长趋势,当冷热侧温差达35℃以上时,膜通量增长速率放缓,兼顾经济与效率计,冷热侧温差以35℃为宜;在实验周期内,膜通量在8.21~8.36 kg/(m2·h)变化,电导率维持在3.8~3.9μS/cm;产水的六价铬浓度12 h之内稳定在0.026~0.03 mg/L,随着膜蒸馏实验的进行,产水浓度开始增大,但均在0.5 mg/L排放标准以下;168 h的长周期实验过程膜通量维持在8.1~8.35 kg/(m2·h),产水电导率维持在3.7~4.3μS/cm,说明以PVDF中空纤维疏水膜为核心的膜蒸馏技术对Cr(VI)具有稳定的去除效果。     

三沙湾渔业水域表层沉积物中油类含量分布及污染状况

本文根据2021年5月(春季)和8月(夏季)的调查资料,对三沙湾渔业水域表层沉积物中油类含量的分布特征及其污染状况进行了研究。结果表明,研究区表层沉积物中油类污染物含量为8.65×10^-6～126×10^-6,平均含量为53.1×10^-6;油类含量呈现春季略高于夏季的季节变化特征;春、夏季平均含量平面分布状况为研究区南部的S2和S8站位以及东部的S3站位高,北部次之,西部的S4站位和南部的S1站位处于较低水平;研究区南部的S2和S8站位以及东部的S3站位油类含量相对较高,可能与该区域网箱养殖、作业船舶(网箱养殖船舶以及其他作业船舶)活动频繁关系密切。与历史资料比较,研究区表层沉积物中油类污染物含量呈逐年增加的变化趋势;与其他海域比较,研究区表层沉积物油类污染物含量尚处于较低的水平。     

海洋环境中诱变剂(Muagens)遗传活性的生物检测

环境中的三致物质(致癌,致畸、致突变)从广义的角度上看也可以统称为诱变剂(mutagens)。诱变剂可以分成二大类,一类是化学的,另一类是物理的。化学诱变剂数量很多,其中包括亚硝酸、甲基磺酸乙酯(EMS)、亚硝基甲基脲(NMU)、羟胺、氯化锂、二硝基甲苯、二溴乙烷、乙烯亚胺、某些石油烃等等。物理诱变剂主要包括宇宙线、     

南朝鲜丽州矿区含金-银热液脉型矿床的流体包裹体和稳定同位素研究

丽州金-银矿区位于汉城东南约60km的朝鲜半岛前寒武纪京畿变质岩带内。该矿区的矿山沿含金热液石英脉分布,这些石英脉穿切了早元古代眼球状片麻岩和中生代花岗岩。矿化分三个阶段(Ⅰ阶段、Ⅱ阶段和碳酸盐阶段),这三个阶段的矿化均充填早期的断层角砾岩带。流体包裹体资料表明,含硫化物-石英的Ⅰ和Ⅱ阶段从早期高温(约350℃)演化至后期较低温度(约180℃)。成矿后的碳酸盐阶段的流体包裹体资料反映出热液流体的温度更低(220—190℃),盐度更低(4—5当量％NaCl)。 流体包裹体和稳定同位素证据证明,银金矿、辉铜银矿、辉银矿、方铅矿和闪锌矿在温度为285—185℃时,从盐度为14.0—2.6当量％NaCl的流体中沉淀出来。流体包裹体的沸腾证据说明,Ⅰ和Ⅱ阶段矿化期间压力小于100bar,相当于深度为500的岩石静压力和1250m的静水压力。 Ⅰ阶段硫化物的硫同位素组成随共生时间而系统地减少,算出的δ~(34)S_(H_2S)值从7.7‰降至0.7‰。流体的硫酸盐/硫化物比值的逐渐增大很可能是由于沸腾时H_2S的丢失以及温度的降低造成的。不仅使δ~(34)S_(H_2S)值随时间而系统地减少,而且可能也导致金因Au(HO)_2~-分解而沉淀。 丽州矿区热液流体的氢和氧同位素值与以大气降水为主一致,而接近于未交换的大气降水值。这些值与南朝鲜其他?     

黄浦江表层水体中低环多环芳烃的分布特征

2005年12月-2006年5月连续监测黄浦江表层水体中低环多环芳烃(LMWPAHs)含量。结果表明,萘、芴、菲和蒽的平均浓度分别为123ng/L,57.8ng/L,58.8ng/L和11.5ng/L。黄浦江表层水体中LMWPAHs的分布主要受人类活动影响,其总浓度沿黄浦江上中下游逐渐升高,在外滩附近,即S6采样点(311°44′6.2″N,1212°92′1.6E″),S7采样点(311°52′8.9″N,213°21′9.7″E)达到峰值。水体中LMWPAHs浓度受季节影响,冬季浓度明显高于春季。其特征化指数表明,黄浦江表层水体中LMWPAHs主要来自化石燃料的不完全燃烧。     

生活垃圾填埋操作方式对覆土中Ⅰ型甲烷氧化菌的影响研究

填埋场覆土中的甲烷氧化菌可削弱填埋场的温室气体释放,其中I型甲烷氧化菌对环境条件的改变反应灵敏.实验采用16S rDNA特异性聚合酶链式反应(polymerase chain reaction,PCR)结合变性梯度凝胶电泳(denaturing gradient gel electrophoresis,DGGE)基因指纹技术研究不同填埋操作方式,包括高密度聚乙烯膜(high-density polyethylene liner,HDPE)隔离、渗滤液亚表面灌溉和植被种植,对城市生活垃圾填埋场表层覆土中I型甲烷氧化菌的群落结构和多样性的影响.16S rDNA序列的系统发育分析结果表明,供试土壤中的I型甲烷氧化菌均属于甲基杆菌属(Methylobacter).从香农-威纳多样性指数(Shannon-Wiener diversity index)和主成分分析的结果可以归纳得到:渗滤液亚表面灌溉和植被种植比HDPE膜隔离对表层覆土中I型甲烷氧化菌群落结构的影响更大,它们会降低I型甲烷氧化菌的多样性,并且推测渗滤液亚表面灌溉会抑制Methylobacter的生长.无HDPE膜隔离的土壤中,即有填埋气体侵入的土壤中,随填埋气体作用于土壤时间的延长,I型甲烷氧化菌的群落结构会发生变化;覆土时间分别为3周、1.5 a和5 a的土壤中,I型甲烷氧化菌的香农.威纳多样性指数在覆土1.5a时达到最大值.     

千岛湖溶解氧与浮游植物垂向分层特征及其影响因素

根据2015年9月对千岛湖坝前湖泊区5个监测点的监测数据,分析了千岛湖溶解氧、水温、pH、浊度、电导率和浮游植物等指标垂向分布特征,并讨论了水体中溶解氧特殊分层与浮游植物垂向分布的影响因素.结果表明:(1)溶解氧垂向分布呈现"表层高,底层低"模式,波动范围在1.95~8.25 mg·L~(-1)之间,平均浓度为5.10 mg·L~(-1).低氧区出现在12~20 m水深,最小值在17 m为1.95 mg·L~(-1).0~12 m内维持在较高水平,垂向差异较小,12~20 m内出现突变骤减,甚至出现缺氧状态(4.0 mg·L~(-1));在20~38 m内溶解氧恢复正常水平,38 m以下因水深增大浓度减小.pH垂向分布与溶解氧分布完全一致,突变区域出现在同一水深.(2)浮游植物垂向上生物量差异明显,S1、S2、S3三断面浮游植物生物量呈现中层表层底层,S4、S5两断面浮游植物生物量底层表层中层,浮游植物在20~30 m区域内生长最好.(3)相关性分析发现溶解氧与水温在温跃层内相关性显著,水体垂向层化作用等物理过程以及浮游生物的活动直接或间接决定了千岛湖湖泊区低氧区的范围与程度.浮游植物与溶解氧、pH显著负相关性,浮游植物在表层主要受水体掺混与溶解氧分层的影响,在底层主要受光照强度的影响.     

缢蛏致病性气单胞菌的分离鉴定及毒力研究

对连云港市连云区2006年7月在养殖缢蛏中爆发的一次流行病进行了病原菌分离、培养、毒力试验和详细的生理生化测定,确定点状气单胞菌为其病原菌;并探讨了该菌在不同盐度波动(S0、S2、S4和S6分别代表盐度波动幅度为0、2、4和6)和不同水温(21℃、25℃、29℃和33℃)条件下对缢蛏存活率的影响,结果表明:S0处理组缢蛏的存活率显著高于S2、S4和S6处理组,而S6处理组缢蛏的存活率显著低于其它处理,S2和S4处理组组间差异不显著;在21℃和25℃温度处理组,缢蛏的存活率为100%,显著高于29℃和33℃温度处理组,而33℃温度处理组显著低于其它处理。     

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.     

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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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.     

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.     

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.