贵州省“十一五”城镇污水处理设施建设绩效评估

通过对贵州省城镇污水处理设施逐一调查研究表明:我省"十一五"城镇污水处理设施能力建设取得跨越式发展,全省投资超过47亿元,新增94座污水处理厂,处理能力140.7万m3/d,配套建设管网2 259 km;建成的污水处理厂总体运行良好、稳定,环保验收合格率达87.23%。通过70个污水处理厂投资、工艺、规模的经济分析和38个污水处理厂运行成本抽样调查分析,表明"十一五"我省城镇污水处理设施建设投资效益良好,主要技术经济指标符合相关要求。     

农村生活污水分散式处理系统与实用技术研究

从农村地理环境、自然条件、经济水平、环境目标要求等实际情况出发,考察分析农村生活污水产生、收集、处理及资源化全过程,就农村生活污水的分散式处理方式提出了分散分质处理和分散混合处理两种系统,并对其组成、特点以及在不同条件下的适用性进行了分析。同时结合工程实践,介绍了几种适合农村生活污水分散式处理实用技术,并对其工艺过程、技术特点、投资、运行费用以及处理效果进行了分析,结果表明:(1)厌氧沼气处理技术投资省、资源化高;(2)人工湿地处理技术COD去除率75%～80%,吨水投资2000～3000元,运行费用0.1元,运行管理简便;(3)地埋式微动力小型二级污水处理装置吨水投资约2000～3500元,运行费用0.5～0.6元;(4)蚯蚓生态滤池、生态厕所管理方便,资源化好,有较好的发展前景。     

低温吸附工艺处理化工生产车间VOCs

采用由颗粒活性炭吸附和水蒸汽解吸组成的两级"吸附-解吸"工艺处理化工生产车间的有机废气,分析处理效果并探讨了可行性。结果表明:在甲醇和甲酸甲酯的浓度分别为4 071～7 456 mg/m~3、6 165～10 914 mg/m~3、一级吸附床温度为5～15℃,二级吸附床温度为0～5℃条件下,两级"吸附-解吸"工艺对甲醇和甲酸甲酯的平均去除率分别为98.15%和91.51%,出口甲醇和甲酸甲酯浓度平均值分别为85 mg/m~3和569 mg/m~3;该工艺具有投资及运行成本低、有机物去除率较高、产品回收价值高等优点,可用于处理并回收化工生产车间的废气。     

混凝沉淀-水解-UASB-泥膜复合A/O组合工艺处理味精污水

采用"混凝沉淀-水解-UASB-泥膜复合A/O"工艺处理含高浓度有机物、氨氮和硫酸根的味精污水。结果表明:该工艺对BOD5、COD、SS、氨氮和TN的去除率分别为99.9%、99.6%、99.0%、97.5%和97.3%,出水水质优于GB 8978—1996《污水综合排放标准》中表4的一级排放标准。该工艺耐冲击负荷能力强、投资省、运行费用低,能创造显著的环境、经济和社会效益。     

电凝聚法处理含重金属综合废水的试验研究

本试验采用自行设计的电凝聚污水处理装置,对含重金属污染物的综合废水进行处理,废水处理能力为1m3/h。结果显示:电凝聚法处理后的出水水质达到污水综合排放标准,对铜、锌、铬等重金属的平均去除率在94%以上,乳化油的平均去除率在99%以上,COD的平均去除率在92%以上;试验装置对进水的流量负荷具有较好的耐冲击性;经济分析结果为,电耗和运行费用分别为1.1kw.h/m3和0.65元/m3。     

钢厂废水深度处理工程设计

天津钢管公司采用"多介质过滤+超滤+反渗透"技术对现有污水处理厂外排水进行深度处理,详细介绍整个深度处理工程的概况、主要单元设计参数、实际运行效果和经济性指标,以期为类似钢厂污水处理厂升级改造提供参考。该工程总设计处理规模为2.40万m~3/d。工程运行实践表明:深度处理系统运行稳定,出水水质满足相关设计标准。其并入原生产新水管网,作为未来生产新水的主要水源,有效节约了水资源费和排污费。系统运行成本为4元/t,年节约费用约1 500万元,具有良好的经济效益和环境效益。     

含油废水粗粒化

抚顺石油化工公司石油三厂的粗粒化装置于1984年11月六个塔均投产,设计能力为525.6t/a,实际能力525.6t/a,废水为石油加工过程中所产生的含油废水和生活污水。整个装置占地面积为406m~2,运转周期2d,投资76.83万元,运行费用2.628万元/a,经济效益20.86万元/a,本装置由石油三厂设计。     

CASS+微絮凝过滤在工业园区污水处理工程中的应用

根据工业园区污水水质特点和处理要求,采用CASS工艺和微絮凝过滤污水处理工艺处理该工业园区污水,污水单位投资为0.192万元/m3,吨水经营成本为0.45元/m3,经过两年多的运行分析,出水稳定达GB 18918—2002《城镇污水处理厂污染物排放标准》中一级A标准。详细介绍了该污水处理厂工艺流程、主要处理构筑物和设备配置等情况,为今后类似工业园区污水处理厂工程设计提供一定的参考。     

物化生化联合工艺处理城市废水生产试验研究

采用物化生化联合工艺进行了城市污水处理的生产性试验 ,试验结果表明 :联合工艺同时具有物化法和生化法的优点 ,用它来处理城市污水时 ,处理效率高 ,时间短 ,运行费用低 ,COD、BOD5、SS、NH3-N、T -P的平均去除率分别为 70 .4 %、83 .2 %、87.1 %、58.6 %、92 .3 % ,污水的总停留时间约 3h,处理每吨污水的运行费用为 0 .33元。污水经处理后出水指标达到国家GB8979- 1 996及广州GD4437- 90城市污水排放一级标准     

压滤-水解酸化-接触氧化-过滤工艺处理玻璃纤维废水

以津武玻璃纤维有限公司玻璃纤维废水处理工程为例,介绍压滤-水解酸化-接触氧化-过滤组合工艺的工程应用,总结并分析了工程设计及运行经验。设计处理流量50 m3/d,进水CODCr,BOD5,SS质量浓度分别为7 200,874,1 562mg/L;运行结果表明:该组合工艺对CODCr,BOD5,SS的去除率达97.9%,92.0%和91.5%以上,出水各项水质指标均达到GB 8978—1996《污水综合排放标准》中的二级排放标准。处理费用仅为1.31元/m3,处理系统运行稳定,耐冲击能力强。     

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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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.