萃取法预处理含α-氯代乙酰丁内酯制药废水的研究

在萃取实验中选择二氯甲烷作为萃取剂,考察了萃取振荡时间、萃取次数、油水比、pH值、萃取温度等因素对CODCr去除率的影响,获得最佳的萃取效果。结果表明:萃取出水CODCr为30420mg/L,去除率为49.3%。出水的BOD5/CODCr的比值达到0.34,符合生化处理条件。在萃取剂的回用中选择洗料—蒸馏方法回收,实验结果表明回收的二氯甲烷对废水进行萃取处理,能够达到良好的处理效果。     

一种用于测定硝基苯废水的预处理方法

染料废水通常含有硝基苯和苯胺类化合物。本文选择了预处理条件,在酸性常压下,蒸馏废水样,以分离苯胺与硝基苯,采用还原—偶氮比色法测定硝基苯。最低检出浓度为0.08mg/l,相对标准偏差为1.1％～1.5％。 1 预处理条件本实验主要考察了pH对预处理蒸馏率的影响。取400ml含有100μg硝基苯的水样,在不同条件下进行蒸馏实验。每次取100ml流出液,共蒸馏4次。测定回收量,结果列于表Ⅰ。由表Ⅰ可知。pH在1～12之间,硝基苯的第一次蒸馏率,均达80％以上,且较相近。而实验观察到,pH为     

油页岩干馏废水吹脱脱氮的影响因素分析

以抚顺某页岩油厂的废水为研究对象,通过单因素实验考察了吹脱法各工艺因素对处理页岩油废水效果的影响,得出最佳工艺条件如下:吹脱时间90 min、气液比120∶1、初始pH值9. 0、温度70℃,此时NH_3-N去除率达到86. 38%。通过正交试验判断各因素对处理效果的影响程度和规律,结合实验研究发现,在水温 70℃,pH值 9. 0的条件下,继续提高pH值只能在实验前期提高NH_3-N去除率,而对最终去除效果影响不大。极差分析得出,各因素对油页岩废水NH_3-N去除率影响的主次顺序为反应时间温度气液比初始pH。根据实验结果分析认为,在吹脱过程中,可充分利用厂内废水温度高(可达70℃)、pH值高(原水pH值9. 0左右)的特点,实现较好的NH_3-N去除效果。     

电解法预处理敌百虫废水的研究

实验研究了电解法作为预处理,降解敌百虫农药废水的效果,详细探讨了电解时间、废水pH值、电解电压、电解电流及加入电解质的质量等因素对电解效果的影响.实验结果表明,在循环电解池中,废水的pH值=6～8时,保持电压在30 V的条件下,废水中CODCr的降解率为40.00%.同样条件下,加入电解质[ρ(NaCl)=10 g·L-1]100mL时,废水的降解率可达到42.80%.     

改性粉煤灰处理洗涤剂废水优化条件的实验研究

利用改性粉煤灰絮凝、高效吸附作用处理洗涤剂废水：通过实验考察改性粉煤灰对洗涤剂废水处理效果影响的一系列参数,由正交实验得到优化实验条件。10g改性粉煤灰处理废水的量为150mL,pH值为7,搅拌时间40min,搅拌温度为50℃。在最佳条件下测得废水的COD和LAS去除率分别为82．48％和67．06％。     

磁流体处理印染废水的实验研究

通过单因素实验,研究了磁流体的投加量、pH值、温度、搅拌时间对印染废水色度和CODCr的去除效果影响.实验结果表明:磁流体A、磁流体B和磁流体C投加量分别为6,4,5 mL,pH值为6,温度为30℃,搅拌时间为15 min时,对印染废水的色度和CODCr值去除效果较好,最高可达95%.     

混合生物制剂对废水中总磷处理效能的模拟实验研究

混合生物茵处理废水是近年来一项正日益得到广泛重视和应用的新型环保技术,本文运用微生物分解有机物技术,从混合生物制剂适宜的环境条件入手,研究总磷水样的浓度、投加量以及pH值、温度等条件对工业废水中总磷去除效果的影响。结果表明,在pH值为8．5～9．0左右,温度在25℃～30℃时混合生物制剂投加量为0．3g对总磷浓度为40．0ug／ml的模拟水样去除效果较好。     

高磷铁矿湿法脱磷废水除磷工艺及其循环利用

以氧化钙为除磷剂,采用化学法对高磷铁矿脱磷废水除磷工艺进行探讨。研究了溶液pH值、反应温度、反应时间及搅拌速度对脱磷的影响。实验结果表明:在酸性含磷废水的pH为10、温度为70℃、反应时间为30 min以及搅拌速度为200 r/min的优化条件下,除磷效果最佳,脱磷率可达99.99%以上,废水的含磷量由3020μg/mL下降到0.5μg/mL以下,完全符合国家第二类污染物综合排放标准的一级标准磷含量要求。采用除磷后废水对高磷铁矿除磷,精矿中的磷含量均在0.1%以下,完全满足高炉冶炼配料要求,达废水减排效果。     

实验室有机废水处理方法探讨

对高校实验室废水的来源、种类及特性进行了阐述,同时对实验室废水的处理及污染防治措施进行了综合论述.以实验室废水为研究对象,通过普通蒸馏回收水样中的有机溶剂,采用Fenton试剂法氧化处理废水.实验结果表明:回收废水中的有机溶剂可使废水的COD值降低30%以上;通过正交试验确定了Fenton氧化反应的最佳操作条件,在此条件下,废水的COD去除率达到74.5%.     

细菌JF901704菌株对铊的吸附特性研究

从某含铊废水中筛选出一株耐铊细菌(菌株序列登陆号:JF901704)菌株,研究了溶液初始浓度、吸附时间、pH值、温度、摇床转速及菌体生物量对铊的吸附效果影响,结果表明,JF901704菌株在铊初始质量浓度20 mg/L,吸附时间60 min,pH值7.0,温度30℃,摇床转速150 r/min,生物量1.0 g/L时,吸附效果最佳,在该条件下,JF901704菌株对铊的吸附率可达89.05%;红外光谱分析结果表明,该菌株细胞壁中的羧基、亚氨基及羟基对铊吸附起主要贡献的官能团。     

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.     

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.     

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.