利用制药废水生产醋酸钠

在制造除虫菊酯类农药时,作为辅助原料的醋酸,使用量大。生产后排出的废水中,还含有较高浓度的醋酸。为了综合利用,变废为宝,现介绍一种利用含醋酸废水制造醋酸钠的生产方法。醋酸提纯:醋酸是一种无色有酸味的有机酸,凝固点16.7℃,常温下沸点118℃;当压力为400mmHg柱时,沸点为98.1℃。因此,我们对含醋酸废水进行减压蒸馏。当加热到98.1℃时,启动真空泵,抽馏醋酸气体,再通过循环冷凝就获得了较纯的醋酸液。醋酸钠的生产:在反应釜中投放一定量的醋酸,蒸气加热到35℃后,增加相应量的氢氧化     

影响水中挥发酚测定的相关因素及注意事项

酚类是指苯及其稠环的羟基衍生物。酚类化合物种类繁多，不同的酚类化合物具有不同的沸点。本文所讨论的是一些与环境因素密切相关的常见酚类化合物，并以沸点低于230℃，且可在蒸馏时能与水蒸气一并挥发馏出的这一类酚类化合物为主要讨论对象。在测定挥发酚中，影响因素很多。如：样品采集及固定，样品预处理，4-氨基安替林(以下简称4-AAP)处理等等，在测定过程中操作不当均会给分析结果带来误差。针对挥发酚的测定中可能出现的问题，从六个方面进行研究探讨，为提高测定挥发酚的精密度和准确度提供科学依据。     

测定固定污染源废气中非甲烷总烃的问题探讨

以HJ/T 38-1999为基础,针对气相色谱法测定污染源废气中非甲烷总烃存在的诸多问题进行探讨,在总烃出峰峰形、废气氧峰值测定、高沸点物质干扰等方面做了研究试验。结果表明,1ml定量环容易造成总烃出现平头峰,改成0.25ml定量环能得到好的峰形;非甲烷总烃的检出限为0.04 mg/m~3(以碳计);氧峰值与氧量具有线性关系,应根据氧量判断氧峰值大小,而不是统一扣除除烃空气氧峰值;废气中存在高沸点组分时,容易吸附于采样容器内壁,将样品加热至100℃再测试可提高该组分的检出率。     

沥青烟气爆炸性的实验研究

介绍了沥青烟气爆炸参数测定的实验装置和方法，并给出了实验结果。分析了沥青温度和烟气浓度对爆炸压力和压力上升速率的影响规律，研究认为当沥青被加热至２５０℃左右、烟气浓度为１０％时，爆炸危险性最大。     

土壤有机质样品前处理简易油浴锅与HH—S型数显恒温油浴锅对比探讨

采用HH—S型数显恒温油浴锅和简易油浴锅对国家标准土壤样品进行样品消解对比试验。结果显示：两种样品前处理方法的测定结果,经t检验无显著差异;HH—S型数显恒温油浴锅消解进行样品前处理时,应把预先加热温度提高为195～200℃,消解温度提高为185～190℃,消解时间要严格控制在5min。     

关于镉及镉污染

镉是银白色有光泽的金属,熔点320.9℃,沸点765℃,相对密度8.642.有韧性和延展性.镉在潮湿空气中缓慢氧化并失去金属光泽,加热时表面形成棕色的氧化物层.高温下镉与卤素反应激烈,形成卤化镉.也可与硫直接化合,生成硫化镉.     

大气VOCs在线分析采样条件的选择及对测定的影响

研究了低温空管冷冻捕集条件对各类VOCs的捕集效率的影响。实验结果表明,60 mL/min流量采集5 min,室温为气态的低沸点卤代烃在-120℃的捕集效率偏低,但较高沸点VOCs在-120℃捕集的响应高于-150℃捕集的响应。10 mL/min流量采集30 min,除乙烷和室温为气态的卤代烃外,其它各类VOCs在-100℃就可以有效捕集,-120℃捕集温度可满足各类VOCs的捕集浓缩要求。捕集温度-150℃,采样流量分别为10 mL/min采集30 min和60 mL/min采集5 min,低沸点化合物的响应无明显差异,高沸点化合物前者响应比后者高10%~27%。相同捕集温度下(-150℃),采样体积从300 mL逐步降低到150 mL、100 mL、50 mL,各类VOCs的响应将同步降低,降低采样体积可用于高浓度样品的测定。     

AgDDC光度法测定水中砷的改进方法

ＡｇＤＤＣ光度法测定水中砷的改进方法江西合成洗涤剂厂任苏明，王燕玲目前二乙基二硫代氨基甲酸银（ＡｇＤＤＣ）光度法测定废水中砷时用ａｇＤＤＣ－三乙醇胺／氯仿溶液作为砷化氢的吸收液。氯仿具有低沸点（６１．５℃），毒性大，使用和贮藏过程中易产生光气等缺点，...     

干式消解-原子吸收光谱法测定土壤中部分重金属的探讨

火焰原子吸收法测定土壤中的铜、锌、铅、镉、镍等重金属时,采用干式消解法对土壤样品进行处理,即在5 0 0℃加热灰化,然后用酸浸提。其测定结果与国家标准分析方法测定结果无显著性差异,对标准样品测定结果准确。测量过程方便快速。     

延迟焦化复合废水处理研究

通过自由沉降和离心分离试验结果的比较，考察了加热离心分离法处理炼油厂含油焦化废水脱除固体颗粒的效果。结果表明，加热离心分离法大大改善了含油焦化废水的脱水和脱固性能，在加热到６０～８０℃时，７５％以上的固体颗粒可被脱除     

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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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.     

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.     

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.     

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.