微生物法处理海上钻井废钻井液

微生物法适用于海上钻井含油废弃物的处理.通过多次对菌株采集、分离、纯化和培养驯化,选育得到了3株对石油烃类有很好降解效果的石油类降解菌;确定了石油类降解菌适宜的生化处理条件:最佳生长及原油降解温度为50℃、最佳生长及原油降解酸碱性环境为pH=6.0、最佳菌株接种量2％、最佳原油初始浓度为500 mg/L.处理后的含油废弃钻井液含油量基本稳定在2 mg/L以下,降解率达98％以上.     

氨氮降解菌的分离、鉴定及降解效果初步研究

以(NH4)2SO4为唯一氮源的培养基中,从活性污泥中分离筛选出8株具有氨氮降解能力的菌株,根据各菌株之间降解率及生长情况的比较,从中筛选出1株对氨氮降解效果较为明显的菌株NX3,经形态学和生理特性初步鉴定其为芽孢杆菌属(Bacillus),分别测定了在不同的氨氮初始浓度、pH值、温度下菌株NX3对培养基中氨氮的降解效果,实验结果表明在初始氨氮质量浓度300mg/L、pH值7.0、温度30℃时,该菌株对氨氮降解效果较好,降解率为45.53%。     

采用原生质体融合技术选育提高氨氮降解效能的光合细菌

将高效降解氨氮的假丝酵母菌Candida sp.与高效降解亚硝酸盐氮的耐盐红螺菌Rhodospeudomonas capsulate进行原生质体融合,探讨原生质体制备及融合的条件,并对融合子进行了筛选。结果表明,原生质体制备的优化条件如下:耐盐红螺菌,溶菌酶量为1.5 mg/mL,EDTA浓度为0.1 g/L,作用时间为45min;假丝酵母菌,蜗牛酶量为0.5 mg/mL,巯基乙醇的质量分数为0.1%,EDTA浓度为1 g/L,作用时间为30 min。两种原生质体在聚乙二醇(PEG-6000)和Ca2+的诱导下发生融合,在添加制霉菌素和链霉素的选择培养基上进行初筛,以生长稳定性及对氨氮、亚硝酸盐氮的降解效能等为指标进行复筛,获得了具有较好降解效能的融合子R1菌株。该菌株对亚硝酸盐氮的降解效能与耐盐红螺菌相同,达到90%以上;对氨氮的降解效能为63%,较耐盐红螺菌提高54%。     

铁炭微电解法去除磺胺类抗生素的研究

近年来,由于抗生素的过量使用和不适当排放引起水体污染问题,使人们对抗生素有效降解方法的探索也日益增多。选取了三种常见磺胺类抗生素,并以其中一种磺胺甲基嘧啶作为主要研究对象,考察了铁炭微电解法对磺胺类抗生素的去除效果及反应过程。首先,通过单因素试验得到了最佳反应条件,即初始pH值为2、铁炭填料填装量为1 g/m L、温度为25℃和曝气量为60 L/h,在该条件下反应8 h,对磺胺甲基嘧啶的去除率可达82.9%,对TOC的去除率达45.2%。其次,通过测定反应中TOC、TN、NO_3~-、SO_4~(2-)、Fe~(2+)、Fe~(3+)的浓度变化趋势,揭示了铁炭微电解法降解磺胺类抗生素的反应途径,即抗生素中的S—N键断裂释放出S、N原子,再经过一系列的氧化还原作用得到进一步去除。     

一株假单胞菌降解间甲酚的特性研究

将菌株Pseudomonas sp.BN5在有氧条件下,以特征污染物间甲酚作为唯一碳源和能源,利用NO-3-N作为电子受体,进行了反硝化特性研究,研究发现,菌株Pseudomonas sp.BN5降解间甲酚的能力可达360 mg/L,在间甲酚初始浓度为360 mg/L时,菌株培养78 h后NO-3-N去除率达到87.8%,在降解过程中亚硝酸积累,随后被还原。     

1株阿魏酸降解菌的筛选与降解特征研究

阿魏酸是导致很多作物产生连作障碍的自毒物质。筛选出1株高效降解阿魏酸的细菌,初步鉴定为葡萄球菌属,命名为AWS4B,研究了AWS4B对阿魏酸的降解特征,探讨了其降解途径。结果表明,当无机盐培养基中阿魏酸的浓度为100 mg/L时,菌株AWS4B72h可降解99.97%。降解过程符合一级动力学模型,反应的活化能Ea为19.88kJ/mol,降解方程常数k0为3.26×10-4,得出了菌株AWS4B降解阿魏酸的预测模型方程。AWS4B降解阿魏酸的底物来源比较广泛。菌株AWS4B对阿魏酸降解的可能途径是非氧化脱羧形成香草醛,再氧化形成香草酸,脱甲基后形成原儿茶酸,最后原儿茶酸苯环裂解后分解为水和二氧化碳,最终实现阿魏酸的降解。     

产胸苷磷酸化酶菌株初筛方法的建立及其应用

建立了一种快速简便地筛选高产胸苷磷酸化酶菌株的初筛方法及其在紫外诱变育种中的应用。结果显示,在液体培养基中,添加25mmol/L胸苷不会影响菌体生长且菌体中的胸苷磷酸化酶能催化胸苷生成胸腺嘧啶,在同等浓度下产物胸腺嘧啶OD290nm远大于胸苷OD290nm,从而导致发酵液OD290nm显著升高,据此建立产胸苷磷酸化酶短乳杆菌的初筛方法。在此基础上结合紫外诱变条件的优化,确定初次紫外照射时间为20 s,停止5 min后再照射10 s、15 s、20 s,控制紫外致死率在80%左右,以此条件构建突变文库。通过初筛和复筛确定突变株EB27、EA42酶活分别达到1.025 U/mg湿菌体和0.916 U/mg湿菌体,较初始菌株提高了50%和35%,且具有良好的遗传稳定性。     

麦芽糖假丝酵母降解苯酚的特性及动力学研究

从活性污泥中分离得到一株高效降解苯酚菌,经形态特征观察和生理生化试验,鉴定该菌株为麦芽糖假丝酵母。该菌株能以苯酚为唯一碳源和能源,最适宜降解工艺条件如下:温度为30℃,初始pH值为7.0,摇床转速为200 r/min。降解试验表明,该菌能在69 h内完全降解1 800 mg/L苯酚。随着苯酚浓度的增加,底物抑制作用增强。菌株的生长动力学过程符合Hal-dane方程,可利用该方程模拟不同初始浓度苯酚的降解过程。     

苯酚降解菌CN-6的分离及其生长特性

从台湾某纺织厂污泥中分离得到一株能够将苯酚作为唯一碳源和能源生长的细菌。根据其形态和生理生化反应结合16S rDNA测定分析,该菌被鉴定为假单胞杆菌(Pseudomonas sp.)。降解特性研究表明,该菌降解苯酚的最适pH和温度分别为8.5和30℃,在此条件下,浓度高达500mg/L的苯酚能被该菌在17 h内将完全降解。在动力学研究中,由于高浓度苯酚对CN-6菌株的降解过程存在底物抑制现象,故采用Haldane非竞争性底物抑制模型,计算确定了模型参数μmax、KS和KI分别为0.452 h-12、8.617 mg/L7、82.4 mg/L,该动力学方程对实验数据能很好拟合。     

高锰酸钾预氧化处理嘧啶生产废水研究

采用高锰酸钾预处理维生素B1厂的嘧啶生产废水,考察了其预氧化效果及影响因素.结果表明,高锰酸钾的最佳预氧化条件:进水pH值为1、高锰酸钾投量为20 g/L、氧化时间为3 h、出水pH调至中性.此时,在245 nm波长下对嘧啶环的去除率为93.2%,对COD的去除率为40.6%,对色度的去除率为100%,BOD_5/COD值由0.18增至0.44,大大提高了废水的可生化性.     

Screening for unicellular algae as possible bioassay organisms for monitoring marine water samples

ECOTOX is an automatic early warning system to monitor potential pollution of freshwater, municipal or industrial waste waters or aquatic ecosystems. It is based on a real time image analysis of the motility and orientation parameters of the unicellular, photosynthetic flagellate Euglena gracilis. In order to widen the use of the device to marine habitats and saline waters nine marine flagellates were evaluated as putative bioassay organisms, viz. Dunaliella salina, Dunaliella viridis, Dunaliella bardawil, Prorocentrum minimum Kattegat, P. minimum Lissabon, Tetraselmis suecica, Heterocapsa triquetra, Gyrodinium dorsum and Cryptomonas maculata. Because of their slow growth the last three strains were excluded from further evaluation. Selection criteria were ease of culture, density of cell suspension, stability of motility and gravitactic orientation. The sensitivity toward toxins was tested using copper(II) ions. The instrument allows the user to automatically determine effect-concentration (EC) curves from which the EC(50) values can be calculated. For the interpretation of the EC curves a sigmoid logistic model was proposed which proved to be satisfactory for all tested strains. The inhibition of the motility was considered as the most appropriate movement parameter as an endpoint. The Dunaliella species had the lowest sensitivity to copper with EC(50) values of 220, 198 and 176 mg/L for D. salina, D. bardawil and D. viridis, respectively, followed by T. suecica with an EC(50) value of 40 mg/L. The Prorocentrum species were found to be the most sensitive with an EC(50) value of 13.5 mg/L for P. minimum Lissabon and 7.5 mg/L for P. minimum Kattegat.     

生物制剂H对水华优势藻的生长抑制作用

生物制剂H是新开发的一种抑制藻类生长的药剂,对应用该生物制剂控制景观水体水华优势藻种--铜绿微囊藻和小球藻的效果及生态安全性进行了研究.结果表明,在铜绿微囊藻初始密度为10^8 cell/L数量级时投加1～15 mg/L的生物制剂H具有很好的生长抑制作用,且优于在初始藻密度为10^9 cell/L数量级时加药的效果;在小球藻初始密度为10^8 cell/L数量级时投加5～15 mg/L的生物制剂H具有较好的生长抑制作用.对加药前后小球藻的扫描电镜（SEM）观察结果显示,加药后其细胞结构发生了破坏性改变.对青鳉鱼的急性毒性试验结果表明,生物制剂H具有良好的生态安全性,其48 h半致死浓度为934.5 mg/L,96 h半致死浓度为718.8 mg/L,安全浓度为93.5 mg/L.     

Evaluating the effect of dissolved oxygen on ammonia-oxidizing bacterial communities in activated sludge

The effect of dissolved oxygen (DO) on the communities of ammonia-oxidizing bacteria (AOB) in activated sludge was evaluated in lab-scale and full-scale reactors using the amoA gene as the basis for phylogenetic comparisons. Under controlled laboratory conditions, two chemostats seeded with activated sludge from the same source were operated with high-DO (8.5 mg/L) and low-DO (0.24 and 0.12 mg/L) concentrations for a period of 300 days. At the end of the operation period, the chemostats had enriched AOB communities that belonged to the Nitrosomonas europaea lineage, but were differentiable based on phylogenetic and kinetic analyses. The low-DO chemostat harbored the growth of two different groups within this lineage, differentiable by the amoA sequence comparison and by terminal fragment signatures. The difference in oxygen affinity between high-DO and low-DO enrichments was demonstrated by evaluating the growth kinetics as a function of oxygen concentration. The low-DO enrichment had a higher growth rate at DO concentrations below 4.7 mg/L, but the growth rate significantly decreased at higher DO concentrations, for which the high-DO enrichment experienced higher growth rates. In addition, the dynamic changes in AOB populations in two parallel trains within one full-scale treatment plant were evaluated in response to a significant reduction of DO in one of the treatment trains. Only the train operated with DO concentrations below 1mg/L favored the establishment of a population of AOB related to the N. europaea lineage.     

多功能微生物制剂用于污泥减量的研究

目前如何减少剩余污泥的产量已成为污水处理的研究热点。为此，基于目前主要的污泥减量理论，在自然界中分离、筛选出一些特殊的微生物菌种，在特定培养工艺下研制一种多功能微生物制剂（MCMP）用于污泥的减量。采用该微生物制剂在重庆长寿污水处理厂进行中试：设3套相同装置，均采用常规活性污泥法且运行操作相同，其中两套装置分别投加所处理水量0．005％和0．01％的微生物制剂，一套不投加，对比其污泥减量效果。试验结果表明：投加MCMP的两套装置的污泥减量比例分别为81．76％和89．18％，3套装置的污泥增长速率分别为2．0％、1．5％和11．5％；投加MCMP能提高出水水质，3套装置出水的COD、NH3-N平均浓度分别为35．08、33．89、36．51mg／L和1．40、1．22、1．62mg／L。投加MCMP不用增设专用的处理单元，也不需改变原有的处理设施及运行方式。3套装置的曝气量相同，因而投加MCMP不会增加整个系统的动力消耗。该制剂具有良好的污泥减量效果，能减轻污水处理厂污泥处理、处置的负担。     

Biodegradation of pyridine using aerobic granules in the presence of phenol

Aerobic granules cultivated with 500mg/L phenol medium effectively degraded pyridine at a concentration of 250-2500mg/L; maximum degradation rate was 73.0mg pyridineg/VSS/h at 250mg/L pyridine concentration. Phenol concentrations of 500-2000mg/L limited pyridine degradation in a competitive inhibition pattern, as interpreted using Michaelis-Menten kinetics with corresponding parameters V(max), K(m) and K(I) of 63.7mg/Lh(-1), 827.8 and 1388.9mg/L, respectively. Fluorescent staining and confocal laser scanning microscopy (CLSM) tests suggested that an active biomass accumulated at the granule outer layer. Denaturing gradient gel electrophoresis (DGGE) fingerprint profile demonstrated that dominating microbial strains exist in phenol and pyridine-degrading aerobic granules.     

Isolation and characterization of bacterial strains capable of growing on malathion and fenitrothion and the use of date syrup as an additional substrate

Four bacterial strains capable of growing on two organophosphorus pesticides (malathion and fenitrothion) were isolated from activated sludge. Among these isolates, the species Stenotrophomonas maltophilia was found to be capable of using fenitrothion as the sole carbon and nitrogen source, and malathion as the sole carbon source. There appear to be no similar reported findings. A crude juice of dates was tested as an additional carbon source for malathion degradation. The biodegradability was significantly enhanced with the supplementation of date juice. The degradation efficiency of the pesticide tested at a concentration of 60 mg/L reached the maximum value of 89% in the presence of date juice at 30 g/L reducing sugar. Statistical screening of four operating parameters (initial biomass concentration, aeration rate, agitation and temperature) for biomass growth and for malathion degradation by acclimated indigenous activated sludge was carried out using a fractional factorial design.     

不同填料对曝气生物滤池除污效果的影响

采用臭氧/BAF组合工艺处理制革园区污水处理厂的二级生化出水,考察了不同填料BAF挂膜启动的运行情况,探讨了臭氧投加量为25 mg/L时不同填料BAF稳定运行的除污效果及机理。平行运行3个BAF,其填料分别为活性炭、陶粒、活性炭/陶粒(体积比为1∶1)。在挂膜启动期间,活性炭和混合填料BAF对COD的去除率表现为先下降再上升最后趋于稳定,32 d后出水COD<60 mg/L,而陶粒BAF对COD的去除效果不明显。稳定运行期间,进水COD、色度平均值分别为117 mg/L和112.5倍,活性炭BAF的出水值则降至50 mg/L和6倍,达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)中的一级B标准。在此期间活性炭、混合填料和陶粒BAF中的生物量分别为30.69、25.87、15.18 nmol/g。     

高效脱硫脱氨氮菌株的分离、鉴定及特性研究

从具有脱臭功能的曝气生物滤池中分离出一株能同时脱硫和氨氮的菌株TS-1.根据形态学、生理生化特征及16S rDNA基因序列分析结果,初步鉴定该菌株为巨大芽孢杆菌(Bacil-lus megaterium).对菌株TS-1的生长性能和脱硫、脱氨氮性能进行了测试,结果表明,在(30±2)℃、转速为150 r/min的条件下,该菌株的最佳生长pH值为7.0,对数生长期为12～32 h;当S~(2-)和NH_4~+-N分别为80、88 mg/L时,对硫化物和氨氮的去除率分别可达91.8%、96.6%,且去除率随底物初始浓度的增加而逐渐降低.     

Treatment of wastewater containing high concentrations of terephthalic acid by Comamonas sp. and Rhodococcus sp.: kinetic and stoichiometric characterization

In this work, terephthalic acid degradation was studied with two strains that were isolated and identified as closely related to Comamonas (99%) and Rhodococcus (99%) genus. A characterization of both strains was carried out during batch experiments performed at two oxygen transfer capacities (0.094 ± 0.011 and 0.538 ± 0.042 g O₂/L/h) and five concentrations of terephthalic acid (2.5 to 15.0 g/L). Maximum degradation rates of 0.073 ± 0.004 and 0.062 ± 0.003 g TOC/L/h, were observed, for Comamonas sp. and Rhodococcus sp., respectively. However, a degradation rate of 0.159 ± 0.011 g TOC/L/h was reached with a mixed culture. Haldane, Aiba, Edwards and Andrews models were used to fit terephthalic acid degradation kinetics, being Haldane the model that best fitted the results. Several parameters were determined including, maximum growth rate, growth yield, substrate affinity and inhibition constant.     

投加有效微生物强化CAST反应器处理含盐废水

将4株耐盐净污菌引入到循环式活性污泥法(CAST)反应器中,构成新型的生物强化CAST含盐废水处理系统。试验表明,在8 h的周期运行工艺中,当耐盐净污菌形成稳定的优势菌群后,可显著提高CAST对COD的去除率,去除率达到90%以上,提高了20%左右;生物强化CAST也具有一定的脱氮除磷能力,其对氨氮的去除率为95%左右、对总氮的去除率为65%左右、对总磷的去除率在30%～75%之间。生物强化CAST主反应池的MLSS值在2 500～4 500 mg/L之间变化。