杀菌灭藻剂对高盐废水生化污泥降解性能的影响研究

为探究某种杀菌灭藻剂对高盐废水处理系统中生化污泥的降解性能的影响,按污水站生化池内污泥浓度向试验装置接种厌氧污泥、好氧污泥,控制与污水站系统相同的运行工况,以出水COD值为评价指标,考察不同的杀菌灭藻剂投加浓度下生化污泥的降解性能差异。结果表明:在本研究探索的投加范围内,杀菌灭藻剂会杀灭或抑制部分生化污泥中微生物,并且杀灭或抑制的速率大于微生物自身增殖的速率;厌氧和好氧反应的COD去除率与投药浓度呈线性关系,与试验时间也呈线性关系,试验进行越久、投加杀菌灭藻剂量越大的试验出水COD越高。     

添加碳氮代谢相关微生物对堆肥过程中菌群结构的影响

堆肥是固体有机废弃物资源化利用的有效方法之一,碳氮代谢是堆肥化进程中的主要生化反应。本文通过筛选出与碳氮代谢相关的微生物并制成菌剂添加到堆肥中,研究添加菌剂对堆肥化的影响,利用PCR-DGGE方法对堆肥化进程中细菌群落进行分析,结果显示:各组堆肥的生物菌群在堆肥过程中的变化趋势是相似的,但添加菌剂减少了堆肥的生物多样性,使有效微生物迅速成为优势菌群,从而促进堆肥腐熟。     

处理BPA模拟废水的SBR工况参数对污泥有机毒性的影响研究

在处理双酚A(BPA)模拟废水的序批式活性污泥系统(SBR)反应器中,保持进水COD含量均为300 mg·L-1左右,通过改变水力停留时间HRT从12~8 h,污泥龄SRT从20~10 d,考察污泥有机毒性和其他水质指标的变化.试验分析了空白组和40 mg·L-1初始浓度BPA对照组在不同工况条件下周期末出水COD值、污泥有机毒性分布规律以及稳定期单周期内COD值和污泥有机毒性的变化趋势.结果表明,缩短水力停留时间和污泥龄有利于活性污泥降解BPA,并消减稳定期污泥的有机毒性;出水COD稳定在50 mg·L-1左右,且水相和泥相均无BPA残留.在应用PCR-DGGE技术分析SBR系统内微生物菌群多样性和不同样品间的相似性过程中,得出污泥总毒性抑制率与微生物多样性呈负相关性关系,进水成分的不同和运行参数改变是导致污泥总毒性差异的主要原因.     

复合垂直流人工湿地的生物强化技术研究

应用复合微生物菌剂和菖蒲对复合垂直流人工湿地系统进行生物强化研究,探讨其能否提高系统的处理效果。将该系统在无强化、复合微生物菌剂强化和植物及复合微生物菌剂同步强化3种工况下的试验处理效果进行比较,发现植物及复合微生物菌剂同步强化工况下的系统处理能力有显著提高,COD和TP出水浓度达到GB 18918—2002《城镇污水处理厂污染物排放标准》一级A排放标准,NH+4-N出水浓度达到二级A排放标准。     

不同石化污泥配比的堆肥处理对青梗菜生长的影响

试验针对石化污泥生物堆肥,开展了五种不同物料配比和是否添加微生物菌剂的对比试验。试验结果表明:随着堆肥物料中石化污泥配比的提高,堆肥的含水率增大,种植青梗菜的平均单株株高、株重减小,单位面积产量也降低。堆肥物料配比相同的处理Ⅱ与处理Ⅴ对比发现,堆肥处理过程中未添加微生物菌剂的处理Ⅴ的青梗菜的平均单株株高、株重、单位面积产量显著低于添加微生物菌剂的处理Ⅱ,甚至低于石化污泥配比为100%并添加微生物菌剂的处理Ⅳ,试验表明,堆肥过程中添加微生物菌剂,其作用不仅可以提高石化污泥生物堆肥的堆体温度,缩短堆肥周期,而且可提高堆肥在农业种植应用中的效果。     

复合微生物菌剂在剩余污泥堆肥中的作用研究

应用复合微生物菌剂对剩余污泥进行堆肥试验,通过测定堆肥过程中微生物总量、温度、C／N,系统地研究了复合微生物菌剂在剩余污泥堆肥系统中的作用。结果表明,利用复合微生物菌剂可以提高剩余污泥堆肥效率、加速堆肥反应过程,对剩余污泥处理及资源化具有重要作用。     

聚甲醛废水的生物强化处理及微生物种群动态分析

聚甲醛工业废水含有甲醛、三聚甲醛和酚类等有害物,而且盐分和COD也较高,很难实现生物处理至达标排放.在聚甲醛污水厂建立中试系统并接种活性污泥,同时投加了经筛选的三聚甲醛降解菌Bacillus methylotrophicus和甲醛降解菌Candida maltosa、Pseudomonsa putida组成的复合菌剂,进行了聚甲醛、甲醛等有毒物质的选择性生物强化,通过温度梯度凝胶电泳(PCR-TGGE)技术对污水反应器进行了微生物群落结构分析,并与污水厂同期出水进行对照研究.结果表明,在投加复合菌剂的强化生物系统中,最终出水的甲醛、三聚甲醛(Trioxane,TOX)和COD降解率分别在97.8%、94.2%和92.6%以上,且系统表现出更高稳定性和抗冲击负荷能力.PCR-TGGE图谱表明,非生物强化系统中未检测到B.methylotrophicus,而该菌在生物强化系统中的活性一直得以维持,其对有毒物质的持续降解解除了其它微生物群落的抑制因子,污泥活性有效增强,说明该菌及复合菌剂确实对TOX及甲醛等毒性物质可有效降解,选择性生物强化可成为工业污水处理的可靠手段之一.     

MBR处理腈纶废水的效能及微生物群落结构分析

采用序批式膜生物反应器(SBMBR)处理腈纶聚合废水和丙烯腈废水,考察了不同废水比例和运行条件下反应器的运行效果,并采用PCR-DGGE技术分析了反应器内微生物群落结构的变化.结果表明,SBMBR对腈纶废水具有较好的处理效果,碳源和碱度不足是影响脱氮效果的两个主要因素;在水力停留时间为24 h,90 min缺氧/150 min好氧交替运行的条件下,COD、NH+4-N和TN的平均去除率分别为82.5%、98.7%和74.6%,出水水质可以稳定达到国家污水综合排放标准(GB8978-1996)的一级标准;PCR-DGGE分析结果表明,反应器内微生物多样性与进水水质和运行条件密切相关,微生物群落呈现出较明显的演替过程;通过克隆测序,从9个污泥样品中成功鉴定获得22种微生物的16S r DNA序列,并筛选出7种降解腈纶废水的优势菌种.     

水生植物对生态-A/O工艺复合系统性能的影响

生态技术与生物污水处理工艺复合系统是一种环境友好、新型高效污水处理技术。研究了水生植物对生态-A/O工艺复合系统除污性能和污泥性能的影响。反应器运行25 d后,添加植物组R2出水中COD、NH~+_4-N、TN和TP去除率分别达96.79%、94.74%、83.67%和41.94%,各项指标均略高于空白组R1。植物生长良好,发达的根系为微生物提供了良好的生长场所,植物根系污泥量较大,出现了大量原、后生动物,丰富了微生物群落多样性。R2污泥EPS中多糖和蛋白质浓度分别为R1污泥中的42.6%和62.1%,污泥沉降性能也得到一定提升。     

生化黄腐酸对活性污泥系统处理废水的强化作用

研究了添加生化黄腐酸对活性污泥工艺处理废水的强化效果。在4个反应器中分别添加0、2、4和6mg/L浓度的生化黄腐酸,反应器采用分批连续运行方式,系统稳定后,考察添加生化黄腐酸对活性污泥工艺运行的影响。结果表明生化黄腐酸能加快废水中COD、氨氮和总磷的去除,促进微生物对难降解有机物的降解,并能降低出水中悬浮固体物的浓度,提高污泥的活性,达到改善活性污泥工艺运行的目的。     

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.     

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.     

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.     

Seed selections for crystallization of calcium phosphate for phosphorus recovery

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.