Conversion regular patterns of acetic acid, propionic acid and butyric acid in UASB reactor

On the basis of continuous tests and batch tests, conversion regular patterns of acetate, propionate and butyrate in activated sludge at different heights of the UASB reactor were conducted. Results indicated that the conversion capacity of the microbe is decided by the substrate characteristic when sole VFA is used as the only substrate. But when mixed substrates are used, the conversion regulations would have changed accordingly.Relationships of different substrates vary according to their locations. In the whole reactor, propionate‘s conversion is restrained by acetate and butyrate of high concentration. On the top and at the bottom of the reactor, conversion of acetate, but butyrate, is restrained by propionate. And in the midst, acetate‘s conversion is accelerated by propionate while that of butyrate is restrained. It is proved, based on the analysis of specific conversion rate, that the space distribution of the microbe is the main factor that affects substrates‘ conversion. The ethanol-type fermentation of the acidogenicophase is the optimal acid-type fermentation for the two-phase anaerobic process.     

Characterization of a strain of Sphingobacterium sp. and its degradation to herbicide mefenacet

A bacterium(designated strain YI) degrading acetanilide herbicide mefenacet was isolated from aerobic sludge. Based on the analyses of partial 16S rRNA gene, cellular fatty acid and BIOLOG-GN, and general physiological and biochemical characteristics, strain Y1 was identified as Sphingobacterium multivolum. Strain Y1 was able to degrade mefenacet used as sources of carbon and energy. Degradation of mefenacet was accompanied by producing the metabolites N-methylaniline and an unidentified compound with molecular weight 205, indicating a metabolic pathway of mefenacet initiated bv hvdrolvsis of amido bond.     

Straw bio-degradation by acidogenic bacteria and composite fungi

A composite microbial system, including a strain of Candida tropicalis (W3), a strain of Lactobacillus plantarm(WY3) and three strains of basidiomycete pL104, pL113 and C33, was chosen to degrade com straw.The final pH was acid owing to the inoculation of acidogenic bacteria, and under this condition the composite fungi system could produce complex enzyme to destroy the compact structure of corn straw. The experimental results showed that the biomass of composite fungi could reach up to maximum when the pH value was 4.5. Through the bio-degradation by combining acidogenic bacteria with the composite fungi system, the cellulose, hemi-ceUulose and lignin degradation rates of corn straw powder were 26.36%, 43.30% and 26.96%, respectively. And the gross crude protein content increased 60.41%. This study provided the evidence for the feasibility of developing a composite microbial system with high capability of degrading straw lignocelluloses in order to make reasonable use of straw resource and protect rural eco-environment.     

Characterization of fine organic particulate matter from Chinese cooking

PM2.5 samples were collected by a three-stage cascade impactor at two kinds of Chinese restaurants to characterize fine organic particulate matter from Chinese cooking sources. Major individual organic compounds have been quantified by GC/MS, including series of alkanes, n-alkanoic acids, n-alkanals, alkan-2-0nes and PAHs.Alkanes and ketones make up a significant fraction of particle-phase organic compounds, ranging from C11 to C26,and (C9 to C19, respectively. In addition, other organic compound classes have been identified, such as alkanols,esters, furans, lactones, amides, and nitriles. The mass concentrations of fine particles, alkanes, n-alkanoic acids and PAHs in air emitted from the Uigur style cooking are hundreds times higher than ambient PM2.5in Beijing.     

Adsorption of phenthoate and acetochlor from water by clays and organoclays

IntroductionImmobilizationorseparationofcontaminantscontainedinpollutedwaterisanobjectiveofincreasingimportanceinavarietyofenvironmentalsettings.Theextentofpesticidecontaminationofthewaterenvironmenthasrecentlyraisedmuchconcernbecauseofthepotentialhealthh…     

流域保护区域协同立法的功能定位与规范进路

《长江保护法》《黄河保护法》为长江、黄河流域的区域协同立法提供了法律依据,在流域保护区域协同立法“入法”后,需要明晰其权力空间与运行规则,提升其科学化、规范化水平。流域保护区域协同立法在本质上仍属于地方立法,是功能主义进路下解决跨行政区域流域保护难题的一种选择,是流域整体性保护的立法回应。就其功能而言,具有落实国家立法确立的流域保护整体目标的实施性功能,以地方合作为中心,解决那些通过单独地方立法难以解决的跨行政区域地方性流域保护问题的协调性、自主性、创新性功能。在此基础上,应当通过明晰其立法层级,建立地方立法规划协同机制,改、废、释的协同机制,交叉备案与后评估机制,深化公众参与机制,完善流域保护区域协同立法的运行规则。     

连续流培养好氧颗粒污泥研究进展

好氧颗粒污泥(AGS)因其沉降性能好,生物量高,抗冲击能力强等优点而受到青睐.相比于传统的序批式反应器(SBR),连续流AGS技术具有易于操作控制以及匹配实际污水厂的大水量,连续流的优势,因而更具有研究价值和应用潜力.通过文献分析和整理,归纳了连续流AGS技术面临的挑战,总结了连续流培养AGS的研究现状和经验教训,并对...     

达县百节"水保生态园区"水土流失治理与生态环境保护

本文反映了严重的水土流失是导致达县百节河小流域生态环境恶化的主要原因。阐述了通过实施水土流失治理三大措施：工程措施、生物措施、农耕措施,有效地控制了水土流失等生态问题,极大地改善了当地生态环境,取得了显著的三大效益：经济效益、生态效益和社会效益。同时陈述了百节河小流域生态园区的建设特色：组织协调部门资金捆绑使用,集中投入：业主参与,责、权、利统一,投资渠道多元化,为水土保持和生态环境建设注入了生机与活力。     

壬基酚对球形棕囊藻的生态毒性效应

为了探讨环境激素类物质壬基酚（Nonylphenol,NP）对海洋赤潮藻的生态毒性效应,实验以球形棕囊藻（Phaeocystis globosa）为测试对象,设置了7个NP质量浓度处理（0、0.1、0.2、0.3、0.4、0.5和0.6 mg·L-1）,实验周期为96 h,测定了各处理组球形棕囊藻的生长、可溶性蛋白质量浓度、光合色素质量浓度、丙二醛（MDA）摩尔分数以及最大光能转化效率（Fv/Fm）等指标。结果表明,NP对于球形棕囊藻的96 h EC50为0.42 mg·L-1;而且,随着NP质量浓度的增加,球形棕囊藻的生长速率、可溶性蛋白质量浓度、光合色素质量浓度以及Fv/Fm等指标的下降幅度更加显著;随着NP质量浓度的增加,球形棕囊藻的MDA摩尔分数明显上升;NP低质量浓度（0.1 mg·L-1）暴露能够使球形棕囊藻的类胡萝卜素质量浓度、可溶性蛋白质量浓度和Fv/Fm等指标高于对照组,说明球形棕囊藻在NP暴露下能够产生毒物刺激效应现象。     

果胶在水处理中的研究进展

果胶作为一种功能多样的生物可降解天然高分子,日益成为研究的热点,并已应用于多种领域。本文综述了果胶在水处理中的研究进展,包括其作为重金属吸附剂和絮凝剂的研究,并对今后的发展前景进行了展望。