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1.
为提高垃圾渗滤液膜浓缩液减量化水平,采用石灰混凝-浸没蒸发协同处理纳滤膜浓缩液,获得了处理过程中水质变化规律。结果表明:单独采用石灰混凝处理,在石灰投加量为2 g/L时,膜浓缩液混凝软化效果最佳;随着石灰投加量增加,此时,膜浓缩液pH=10.58,硬度去除率为29.1%,COD去除率为24.1%,NH3-N去除率为67.3%。。采用石灰混凝-浸没蒸发协同处理,石灰投加量为2 g/L、浓缩倍率为10时,蒸发残液软化效果进一步提升,较单独处理,硬度去除率由29.1%提升至65.9%,COD去除率由24.1%提升至41.2%,NH3-N去除率由67.3%提升至81.4%;K+浓度由样液中4300 mg/L提高到36210 mg/L、Na+浓度由5860 mg/L提高到48300 mg/L,为资源化利用提供了条件;冷凝液ρ(COD)由26.3 mg/L降低至16.3 mg/L,ρ(NH3-N)由2.0 mg/L降低至1.4 mg/L,出水可满足GB 16889—2008《生活垃圾填埋场污染控制标准》相关要求。 相似文献
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采用Fe/C微电解-Fenton氧化联合工艺处理某固体废弃物处理企业填埋区的垃圾渗滤液,以降低其COD与浊度值,并去除渗滤液中的重金属离子。结果表明:当pH=4~5,铁炭复合材料投加量为30~40 g/L,曝气量为40 L/min,水力停留时间(HRT)为1 h时,微电解方法对垃圾渗滤液中的Ni2+、Cr(Ⅵ)、Pb2+的去除效果较好,其去除率分别达到 96%、97%和96%,垃圾渗滤液色度去除率为92.41%,COD去除率为62.33%,浊度由40.73NTU降至3.09 NTU,COD由579.2 mg/L降至218.16 mg/L。对微电解工艺出水进一步采用Fenton氧化工艺处理,结果表明:当Fe2+浓度为0.007 mol/L,氧化时间为90 min,n(H2O2):n(Fe2+)=1.2:1条件下,COD去除率为67.50%,浊度为53.20%,处理后的出水浊度为1.47 NTU、COD为69.49 mg/L,达到GB 18918-2002《城镇污水处理厂污染物排放标准》的二级排放标准。 相似文献
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为了降低准好氧矿化垃圾床渗滤液尾水中有机物浓度和提高体系可生化性,构建了GAC(粒状活性炭)-O_3/H_2O_2体系催化降解矿化垃圾床渗滤液尾水中有机物.同时,考察了体系O_3、GAC和H_2O_2投加量、初始pH值对GAC-O_3/H_2O_2体系处理渗滤液尾水的影响,并使用分子量分布、紫外-可见光谱和三维荧光光谱解析了难降解有机物在GAC-O_3/H_2O_2体系的转化机制.结果表明:在GAC投加量为10 g·L-1,O_3投加量为32.16 mg·min-1,H_2O_2投加量为3 m L·L-1,初始pH值为5的条件下,反应20 min后,其渗滤液尾水的COD和UV245分别从700.08 mg·L~(-1)和0.488下降到393.85 mg·L~(-1)和0.244,COD和UV254的去除率分别为43.80%和50.00%.经GAC-O_3/H_2O_2体系处理后,得益于含芳香环有机物的有效降解,渗滤液尾水中大分子有机物(大于50 k Da)明显减少,分子量小于1 k Da的有机物比例增多.与此同时,紫外区类富里酸荧光区及可见光区类富里酸荧光区峰值也大幅降低,其去除率分别为70.20%和58.69%,B/C从0.04增加到0.35,这也使得废水可生化性大幅提高. 相似文献
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采用铁炭微电解-Fenton联合工艺处理制药废水生化出水,探讨了初始pH对微电解过程COD降解速率、出水中Fe2+和Fe3+变化规律以及后续Fenton氧化效果的影响,为优化联合工艺提出了微电解反应pH过程控制的理论。采用pH过程控制时,微电解对COD降解速率大大提高,降解过程基本符合零级反应动力学,同时可大大提高Fe2+和Fe3+浓度及总铁析出量。试验结果表明:当初始pH=2.5,以3.0L/h连续性投加稀硫酸100 min,曝气微电解反应2 h,出水再投加1.0mL/L的H2O2进行Fenton氧化2 h,出水COD总去除率可达85.6%;采用pH过程控制可将微电解出水ρ(Fe2+)浓度从48.6 mg/L提高至149 mg/L,COD降解速率从10.9 mg/(L·h)提高至23.8 mg/(L·h)。 相似文献
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H2O2-Fe2+法处理精喹禾灵生产废水的研究 总被引:1,自引:0,他引:1
采用酸析法先对精喹禾灵生产废水进行预处理然后用H_2O_2-Fe_~(2 )法进行催化氧化,研究了H_2O_2投加量及投加方式、Fe~(2 )投加量、反应时间对处理效果的影响。结果表明,在H_2O_2投加量为12g/L,分批投加,Fe~(2 )投加量为300mg/L,反应时间为90min、pH=2~4的条件下,氧化,出水经活性炭吸附后废水的COD和色度的去除率分别可达94.5%和96.7%,用石灰乳中和后可直接排放,达到了国家二级排放标准(GB8978-1996)。 相似文献
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催化臭氧氧化预处理垃圾渗滤液 总被引:2,自引:0,他引:2
采用浸渍法制备载铜活性炭催化剂,系统地研究了催化氧化法对垃圾渗滤液中的COD和氨氮去除效果,对臭氧氧化和催化臭氧氧化效率进行了对比。在该方法下制备的催化剂中,活性组分金属铜的含量为2.89%。结果表明:在投加催化剂的情况下,COD的去除效率可得到显著提高。实验结果表明:处理COD为4980mg/L,氨氮为2100mg/L的垃圾渗滤液废水,在室温、pH为3、反应时间为120min、催化剂投加量为150g/L、臭氧的流量为5.2mg/min的条件下,废水中的COD及氨氮的去除率分别达到达81.9%和99.04%。 相似文献
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Fenton法处理垃圾渗滤液的研究 总被引:5,自引:0,他引:5
采用Fenton法氧化处理中年垃圾渗滤液生化出水,对影响双氧水利用率及COD去除率的各种因素,包括初始pH,H2O2/Fe2+比率,双氧水投加量、催化剂类型及反应时间等进行了研究。结果表明:Fenton法氧化处理中年垃圾渗滤液生化出水的最佳条件是:初始pH值为7,H2O2/Fe2+比率为4∶1,双氧水的经济投加量为0.05 m ol/L,反应时间为3.5 h。此时,混合催化剂可提高双氧水的利用率,双氧水利用率为153.9%,COD去除率可达80.5%,处理出水可达到GB 16689—1997《生活垃圾填埋污染控制标准》二级标准(COD≤300 m g/L)。 相似文献
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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. 相似文献
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Arsenic uptake by arbuscular mycorrhizal maize (Zea mays L.) grown in an arsenic-contaminated soil with added phosphorus 总被引:1,自引:0,他引:1
XIA Yun-sheng CHEN Bao-dong CHRISTIE Peter SMITH F Andrew WANG You-shan LI Xiao-lin 《环境科学学报(英文版)》2007,19(10):1245-1251
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. 相似文献
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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. 相似文献
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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. 相似文献
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Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes 总被引:2,自引:0,他引:2
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. 相似文献
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Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture 总被引:7,自引:0,他引:7
RemovalofheavymetalsfromsewagesludgebylowcostingchemicalmethodandrecyclinginagricultureWuQitang,NyirandegePascasie,MoCehuiF... 相似文献
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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. 相似文献
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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. 相似文献
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Organochlorine pesticides in soils under different land usage in the
Taihu Lake region, China 总被引:11,自引:0,他引:11
WANG Fang JIANG Xin BIAN Yong-rong YAO Fen-xi GAO Hong-jian YU Gui-fen Jean Charles MUNCH Reiner SCHROLL 《环境科学学报(英文版)》2007,19(5):584-590
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. 相似文献
20.
Alisa Wangsongsak Suwimol Utarnpongs Maleeya Kruatrachue MathurosePonglikitmongko Prayad Pokethitiyook Thitinun Sumranwanich 《环境科学学报(英文版)》2007,19(11):1341-1348
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. 相似文献