Identification and comprehensive evaluation of a novel biocontrol agent Bacillus atrophaeus JZB120050

Abstract

Bacillus spp. have long been used as biocontrol agents because of their efficient broad-spectrum antimicrobial activity. We identified a novel strain of Bacillus atrophaeus, named JZB120050, from soil. B. atrophaeus JZB120050 had a strong inhibitory effect against Botrytis cinerea and many other phytopathogens. Gas chromatography-mass spectrometry showed that B. atrophaeus JZB120050 produced many secondary metabolites, such as alkanes, alkenes and acids; some of which were related to pathogen inhibition. Enzyme activity analysis showed that B. atrophaeus JZB120050 secreted cell-wall-degrading enzymes, including chitinase, glucanase and protease, which degraded fungal cell walls. Both the novel glucanase gene bglu and chitinase gene chit1 were cloned and heterologously expressed in Escherichia coli and the products showed strong enzyme activity. In addition, B. atrophaeus JZB120050 secreted siderophores and formed a significant biofilm. Future studies should focus on these antimicrobial factors to facilitate widespread application in the field of agricultural biocontrol.     

含铬(Ⅵ)污水对地下水、土壤污染的研究

通过模拟含铬（Ⅵ）污水的土壤淋滤过程，结合受污染区域土壤垂直含铬分布分析，研究了含铬污水渗漏对地下水、土壤的污染。结果表明：含铬污水在亚粘土、亚砂土、砂土中的平均渗透系数分别为６．０２×１０－６ｃｍ／ｓ、３．８７×１０－４ｃｍ／ｓ、５．３２×１０－４ｃｍ／ｓ。含铬污水排放会在土壤中沉积铬，引起土壤污染，并污染地下水。     

干湿球湿度仪在电子束辐照烟气脱硫脱硝工业试验中的应用研究

介绍了自制湿度仪的设计思想、测湿原理、系统构成和在电子束辐照烟气脱硫脱硝工业试验装置中的应用情况。试验表明,该仪器能够准确地连续检测烟气湿度,并具有较强的耐腐蚀、耐污染性能,较好地适应了工业试验装置这种湿度大、腐蚀性强、烟尘浓度高的复杂烟气条件。     

垂直流人工湿地水力学特点对污水净化效果的影响

通过在污水中加入示踪剂,研究了人工湿地的水力学特点及其对污水净化效果的影响规律.结果表明,影响水力学各特点的主要原因是湿地植物根系所造成的物理学和生物学上的效应.水力学各特点与污水净化效果之间存在着密切关系:出水快、出水量大的系统具有较好的净化效果;除无植物系统外,停留时间较长的系统有较好的净化效果;容水体积大的系统净化效果也较好;水力负荷则主要通过影响其他各水力学特点而影响净化效果.结果表明,对水力学特点的优化将极大地促进污水净化效果的提高.     

Fenton试剂催化氧化降解含硝基苯废水的特性

探讨不同氧化剂和催化剂浓度下Fenton试剂氧化降解硝基苯的作用规律,用一元线性回归方程对不同氧化降解时间后硝基苯的相对残余浓度对反应时间的相关性进行了定量分析,结果发现硝基苯的Fenton试剂氧化降解符合一级反应动力学模式,通过回归求出了各反应条件下的一级速率常数.实验中还发现以Fenton反应过程中产生的铁离子的复合物代替Fe²⁺作为催化剂时Fenton反应不仅取得了较高的催化反应速率和降解效率,而且对硝基苯具有明显的专属性,硝基苯的降解速率可由原来的17.48mg/(L·min)提高到71.22mg/(L@min),反应5min的硝基苯去除率由9.74%提高到91.79%.用人造沸石为载体吸附该物质制成的非均相催化剂同样具有良好的催化性能.另外,在体系中引入紫外光可以促进废水中CODCr的进一步降解,提高有机物降解速率.     

制药废水预处理技术探索

采用CAF涡凹气浮装置对制药废水进行预处理,考察了pH,温度,药剂对出水效果的影响,中试运行结果表明了CAF涡凹气浮在制药废水预处理方面的良好效果和应用前景。     

长江三峡区间数字流域水系的构建

基于全球陆地一公里基础高程GLOBE数据,采用Martz和Garbrecht研制的数字高程流域水系模型自动提取长江三峡万县－宜昌区间的河网水系、各子流域分水线、河网与子流域编码及河网结构拓扑关系,从而构成该区域的数字流域和数字水系。结果表明该模型生成的水系是可以接受的,与1：10万地形图上长江三峡万县－宜昌区间的水系一致,这为空间分布式模型的建立提供了必备的空间信息数据。最后,探讨了数字流域水系在流域生态学中的应用前景,构建的数字水系可为中惊讶以上流域水体和水生生物的资源保护与合理利用提供决策平台,服务于社会经济的可持续发展。     

Synthesis and application of Cu-BTC@ZSM-5 composites as effective adsorbents for removal of toluene gas under moist ambience: kinetics,thermodynamics, and mechanism studies

Metal organic frameworks (MOFs) are excellent adsorbents that provide abundant specific surface area, adjustable pore structure, and rich active sites. The purpose of this study was to prepare composites with hydrophobic and high microporous specific surface area and to adsorb toluene gas in moist ambience. An ethanol activation-assisted hydrothermal method was proposed to synthesize copper-benzene-1,3,5-tricarboxylic acid (Cu-BTC) metal-organic framework, Cu-BTC, and ZSM-5 molecular sieve composites (Cu-BTC@ZSM-5). The dynamic adsorption process of toluene on different adsorbents was investigated, and the results showed that the toluene adsorption capacity of Cu-BTC@ZSM-5 (158.6 mg/g) was 2.53 times higher than Cu-BTC (62.7 mg/g), when the ZSM-5 content is 5% and the humidity is 30%RH. Compared with other factors, the humidity inhibited the adsorption of toluene on Cu-BTC@ZSM-5. Langmuir model and the pseudo-second kinetics model can better describe the adsorption behavior of Cu-BTC@ZSM-5. The thermodynamic results showed the adsorption process was a spontaneous exothermic process at low temperature and mainly physical adsorption. The relative regenerability can still up to 80.4% after six cycles. The adsorption mechanisms of Cu-BTC@ZSM-5 were pore-filling adsorption, π-π interaction, cation-π bonding, and hydrophobic interactions. This study will help to design a systematic route to evaluate the adsorption performance of Cu-BTC@ZSM-5 for toluene.

     

Association of sleep problems with urinary concentrations of personal care and consumer product chemicals: a nationally representative,population-based study

Environmental Science and Pollution Research - Sleep problems are common in modern society and may be related to environmental chemicals. The objective of this study is to investigate the...