Biodegradation of 2-ethylhexyl-4-methoxycinnamate in river sediments and its impact on microbial communities

Numerous studies have evaluated the toxicity and endocrine disrupting properties of organic UV filters for aquatic organisms, but little is known about their biodegradation in river sediments and their impact on microorganisms. We have set up the sterile and microbiological systems in the laboratory, adding 2-ethylhexyl-4-methoxycinnamate (EHMC), one of organic UV filters included in the list of high yield chemicals, at concentrations of 2, 20 and 200 μg/L, and characterized the microbial community composition and diversity in sediments. Monitoring of EHMC degradation within 30 days revealed that the half-life in the microbial system (3.49 days) was much shorter than that in the sterile system (7.55 days). Two potential degradation products, 4-mercaptobenzoic acid and 3-methoxyphenol were identified in the microbial system. Furthermore, high-throughput 16s and 18s rRNA gene sequencing showed that Proteobacteria dominated the sediment bacterial assemblages followed by Chloroflexi, Acidobacteria, Bacteroidetes and Nitrospirae; Eukaryota_uncultured fungus dominated the sediment fungal assemblages. Correlation analysis demonstrated that two bacterium genera (Anaerolineaceae_uncultured and Burkholderiaceae_uncultured) were significantly correlated with the biodegradation of EHMC. These results illustrate the biodegradability of EHMC in river sediments and its potential impact on microbial communities, which can provide useful information for eliminating the pollution of organic UV filters in natural river systems and assessing their potential ecological risks.     

Evaluation of decentralized treatment of sewage employing bio-contact oxidation reactor integrated with filter bed

A bio-contact oxidation reactor integrated with filter bed (COR-FB) was developed for decentralized treatment of sewage, which consisted of a biofilm reactor and a gravitational filter bed. It has been investigated to treat municipal wastewater for reuse. The evaluation of COR-FB performance demonstrates that it produced good quality effluent regarding carbonaceous compound, nitrogenous compound, suspended solid and fecal coliform. The efficiencies of COD, NH₄⁺-N, TN, TP and turbidity removal were 90.7%, 81.4%, 64.6%, 60.1% and 96.7%, respectively. The residual geometric mean of fecal coliform counts in the final effluent of COR-FB was only 7.8 × 10³ MPN/10³ ml, corresponding to removal value of 3.8 log 10. However, TP removal indicates the necessity of an addition of a bagger and mud valve or an enhanced chemical phosphorus removal prior to treated water reuse. Microfauna communities were monitored in COR-FB, which was found to contain 5 genres and 19 species in the biofilm layer. Also, a simple kinetics model for COR-FB was developed based on the influent, effluent soluble COD concentration and the reaction time by regression simulation. In general, available data proved that COR-FB system can be recommended as a compact and cost-effective technology for decentralized treatment of sewage, especially for developing countries.     

有机-无机肥配施对紫色土坡耕地氮素淋失的影响

通过坡地渗漏小区定位试验,研究总施氮量相同情况下,施肥方式对紫色土坡耕地氮素淋失的影响.结果表明,有机-无机肥配施会影响紫色土硝酸盐向下累积过程,显著降低紫色土坡耕地硝酸盐累积量.渗漏液中硝态氮含量在0.15～46.99mg·L-1之间,占总氮含量的66.4%～96.3%;总氮淋失量在(4.05±0.37)～(37.82±0.86)kg.hm-2之间,占当季施氮量的2.7%～25.2%.在维持总施氮量相同的条件下,与常规氮磷钾施肥相比,农家肥、秸秆与化肥配合施用的渗漏液总氮含量分别降低了71.0%、61.4%,总氮淋失量分别降低了48.1%、31.6%.这表明有机-无机肥配施能显著降低紫色土坡耕地氮素淋失量,对有效控制紫色土区浅层地下水硝酸盐污染具有重要作用.     

重视未遂事件管理持续改进HSE工作

2007年1月,笔者在中国石化销售公司举办的地市公司经理书记培训班上,听到合资公司介绍对未遂事件管理的做法时,深有感触.合资公司进入国内成品油市场时间不长,但在安全管理上却有许多值得借鉴的地方.如BP(浙江)公司把HSE工作量化,把事故预防工作落到实处,把对未遂事件管理作为HSE体系运行的重要过程和内容,成为培养员工安全意识和提高事故预防能力的重要手段.     

青霉素钠在土壤中的吸附和淋溶特性

分别采用振荡平衡法和土柱淋溶法分析了青霉素钠在不同土壤中的吸附和淋溶特性及其影响因素。结果表明,25℃以下,3种供试土壤对青霉素钠的吸附特性能用Freundlic模型进行较好的拟合,江西红壤、太湖水稻土和东北黑土的吸附常数KF分别为30.73、39.26和64.58 m L·g-1。偏最小二乘法(PLS)分析表明土壤黏粒含量和有机质含量是影响土壤吸附青霉素钠的主要因素。供试土壤对青霉素钠的吸附自由能变化值均40 k J·mol-1,该吸附过程主要属于物理吸附,吸附能力由大到小依次为东北黑土、太湖水稻土和江西红壤。土柱淋溶试验结果显示,土壤有机质含量和黏粒含量亦是影响淋溶过程的主要因素,青霉素钠在土壤剖面中的迁移能力较弱,3种土壤淋溶性能由大到小依次为江西红壤、太湖水稻土和东北黑土。     

The time process of post‐earthquake recovery: the Yao'an earthquake in China

Post‐disaster recovery is a constantly changing and developing process. The authors conducted three real‐name follow‐up surveys at 1, 12 and 18 months after the Yao'an earthquake, which had a surface wave magnitude of 6.0. They also calculated recovery ratios at different times and drew post‐earthquake domestic life recovery curves. Based on the recovery curves, the time trajectory of domestic life recovery takes on an approximate S‐type development and change process. The recovery time process of domestic life can be divided into four periods: emergency period (weeks 0–2(5)), early recovery period (weeks 2(5)–24), rapid recovery period (weeks 24–34) and late recovery period (weeks 34–60(80)).     

异地栽培对云南粳稻育成品种品质性状的影响

以15个云南粳稻育成品种(Oryza sativa L.)为试验材料,研究异地栽培对稻米品质性状的影响.结果表明:云南粳稻在温度相对较高的韩国水原种植,其粒长、粒宽、垩白粒率、精米白度、味度值、最高黏度值、崩解值极显著增加,长宽比、糙米率、精米率、整精米率、碱消值、直链淀粉含量、蛋白质含量、消减值和到达最高黏度时间极显著降低,而最低黏度值、最终黏度值和起浆温度不因栽培环境改变而发生明显变化.品质性状对栽培环境的反应不仅与具体的品质性状有关,也与品种密切相关.对环境反应最敏感的品质性状是垩白粒率,环境反应指数变幅为100.3%～2 077.8%,平均值为318.9%,变异系数为204.7%.其次依次是崩解值、消减值和精米白度,环境反应指数分别为202.8%、47.5%和123.1%,对环境反应最迟钝的品质性状是起浆温度和粒长.环境反应指数分别为100.2%和97.3%,其余性状对环境反应较敏感.最低黏度和最终黏度值对环境反应在品种问存在较大差异,有的品种在韩国水原种植这两项特征值增加,有的品种则降低.     

燃烧油品的沸溢特性分析研究

分析了油罐火灾中燃烧油品的沸溢现象,阐述了沸溢发生的条件,研究了沸溢时火焰的热辐射强度,研究表明沸溢时火焰温度平均升高300℃左右,火焰平均热辐射强度是沸溢发生前的2.5～3倍.     

基于景观格局的辽河三角洲湿地生态安全分析

以1990年和2005年遥感影像为基本信息源,在GIS技术支持下,在对辽河三角洲湿地景观格局分析的基础上,采用破碎度、分离度、优势度等景观格局指数和景观类型脆弱度为评价指标研究辽河三角洲湿地景观生态安全。20世纪90年代以来大规模的资源开发,加剧了辽河三角洲湿地景观的破碎化程度,使景观优势度增高,多样性下降。从1990-2005年,研究区主要湿地景观类型水稻田、苇田、滩涂的干扰程度有所增加,生态安全度均有所下降,表明人类对自然湿地生态系统的干扰越来越明显。总体来说,15年来研究区整体景观生态安全度呈现下降趋势。以往湿地生态安全的研究主要集中在环境脆弱性和保护策略方面,研究层次着重在生态系统层面,而从景观格局角度对湿地景观生态安全的研究涉及较少,文章涉及的是景观生态学可持续发展研究的一个新领域,所提出的内容实质上是景观生态安全定量表征的方法探讨。应用景观生态学方法研究生态安全,揭示景观结构与功能关系并进一步分析区域生态环境的变化趋势及其内在因素,不但为辽河三角洲湿地及其生物多样性的保护和资源开发提供了科学依据,而且丰富和发展了我国生态安全研究的理论与方法。     

水质管理信息系统的开发与设计

水质管理信息系统(WQMIS)与一般的水质信息系统(WQIS)不同,它既是各种水质信息的数据库,又是为水质管理决策服务的信息处理系统,它可以定义为:由人、机组成的,进行水质数据贮存、转换、加工并利用所转换的信息来进行水质评价、模拟、预测、控制和规划的计算机辅助管理系统。美