Identification of causative compounds and microorganisms for musty odor occurrence in the Huangpu River, China

There are regular problems of musty odor in the Huangpu River,a major source of drinking water for Shanghai,China.In this study,the musty odor and its main causative compounds in the Huangpu River source water were confirmed through a yearly investigation using flavor profile analysis combined with HSPME-GC-MS analysis.The investigation showed that 2-methylisoborneol (2-MIB) with a concentration level between 28.6 and 71.0 ng/L was responsible for the musty odor in summer from July to September.Microscopic observation confirmed with the cloning results showed that Phormidium spp.,which accounted for 80%-95% of the algal cell density,was the microorganisms responsible for the production of 2-MIB and the estimated 2-MIB yield was 0.022 pg/cell.Results from a wide-area sampling campaign in the Huangpu River watershed showed that,other than the large tributaries receiving water from Tai Lake,several small creeks close to the intake may have contributed most of the 2-MIB and the Phormidium spp.to the Huangpu River source water.This study provides methodology for the investigation of odor causing compounds and microorganisms in river-type source water,and the result will be useful for water quality control in both source water and drinking water.     

SDS-PAGE和HPLC-荧光检测分离鉴定恩施高硒区大豆中含硒蛋白

采用凝胶电泳技术分离恩施高硒地区大豆中的含硒蛋白组分,分辨出２７条蛋白条带。用高效液相色谱－荧光测定对这些条带分别进行硒含量测定并进行空白扣除,发现其中有１３条带含硒。用标准分子量蛋白标定含硒蛋白组分分子量分别为：５８．１－６０．３;５２．５－５３．７;４６．８－５０．１;２９．５－３０．９;２８．８;２５．１－２５．７;２４．３;１９．７－２０．９;１８．４－１８．６;１６．８－１７．９;１６．     

北京市水资源数据管理系统

介绍了《北京市水资源数据管理系统》的概况,以水资源、环境与社会经济活动信息为基础,采用计算机技术建立包括社会经济活动、水资源开发、城市排水、水污染环境质量等各类信息的具有空间特征的水资源宏观数据管理体系,并为政府有关部门提供可靠的决策依据。     

溶解性有机碳的主要组成对青鳉鱼铜急性毒性的影响

为揭示溶解性有机碳(DOC)的组成对生物配体模型(BLM)预测铜的生物毒性准确性的影响,研究了不同浓度黄腐酸(FA)、腐殖酸(HA)和两者不同浓度比例混合物影响铜对青鳉急性毒性。结果表明:在相同水质条件下,黄腐酸或腐殖酸浓度增加时,铜对青鳉的LC50均增加;两者共存时,当腐殖酸质量百分比从10%增至90%时,铜对青鳉的LC50也增加。当天然水中DOC的组成不确定时,可假设HA和FA的组成比例为1∶1,此时BLM预测铜对青鳉的LC50的偏差最小。     

热压机防火问题探讨

针对企业在热压机防火 方面的薄弱环节,具体分析着火原因,从多方面提出了防范措施。     

Dissipation of triadimefon on the solid/gas interface.

The dissipation of triadimefon, as pure solid and in the Bayleton 5 commercial formulation, was studied under controlled and natural conditions. Volatilization and photodegradation were shown to be the main dissipation processes. The volatilization results can be described by an empirical model assuming exponential decay of the volatilization rate. The filler of the commercial formulation is determinant for the volatilization but has little effect on the photodegradation rates. The main photoproducts were identified and a reaction mechanism proposed.     

基于BP和RBF神经网络的外加碳源量模型研究

碳源作为反硝化过程的电子供体,是影响生物脱氮过程的重要因素,低碳氮比污水需外加碳源以保证反硝化反应的顺利进行.为了优化控制碳源投加量,对实验室搭建的CAST工艺污水处理装置的进水条件和外加碳源量的非线性关系分别进行了基于BP和RBF神经网络的模型研究,并对外加碳源量进行了预测.结果表明,两种网络模型均能有效预测外加碳源量,RBF神经网络模型在训练速度和逼近能力方面优于BP神经网络模型,但在预测性能方面BP神经网络模型则有更高的预测精度.     

基于三角随机模拟的生活垃圾填埋场地下水环境健康风险评价模型

基于US EPA健康风险评价方法,将三角模糊数和随机模拟方法进行耦合,建立基于三角随机模拟的地下水环境健康风险评价模型,并以我国北方某生活垃圾填埋场为例,进行地下水环境健康风险评价。结果表明：6口地下水水质监测井的儿童健康风险均超过可接受水平,其中Z1和Z2监测井的风险值均分布于Ⅲ、Ⅳ 2个风险等级;3口监测井的成人健康风险超过可接受水平,其中Z6监测井的风险值分布于Ⅴ、Ⅵ 2个风险等级。与常规确定性方法的评价结果进行对比分析可知,该模型在一定程度上解决了传统确定性评价方法存在的不确定性问题,不仅可以判定地下水污染可能隶属的风险等级,而且可以定量得出其相应的概率水平,可为决策者提供更加精确的环境健康风险评价信息,为地下水污染管理工作提供依据。     

Red mud-modified biochar reduces soil arsenic availability and changes bacterial composition

Environmental Chemistry Letters - Worldwide arsenic (As) contamination in soils induces pollution of surface and ground waters, reduces crop quality and yield, and threatens human health....     

Plants with phytotoxic potential: Wollemi pine (Wollemia nobilis)

Herbicide resistance in annual ryegrass (ARG, Lolium rigidum) threatens the quality and yield of winter wheat crops in Australia, prompting research to discover novel natural plant compounds with herbicidal properties. Due to its novel nature and potentially interesting chemistry, the Australian native, Wollemi pine (Wollemia nobilis), was tested for its ability to suppress ARG growth and its feasibility for use in weed control strategies. The leaf extract of Wollemi pine significantly inhibited the growth of ARG and wild radish (Raphanus raphanistrum) in laboratory bioassays at concentrations above 1% extract. In soil trials, the 100% extract (100 g dried plant material/L) inhibited the dry weight of ARG by 25%. The addition of a wetting agent to the extract increased the suppression of ARG to 80% which was as phytotoxic as a 4-fold increase in the extract concentration (“400%” extract). Using bioassay-guided fractionation, the most phytotoxic fraction was identified and further analysed via GC/MS. Several compounds not previously identified in Wollemi pine leaf extracts have been identified, namely, 2-propylphenol, 3,4-dimethoxyphenol, 2-methoxybenzoic acid, vanillyl alcohol and isovanillic acid. These results suggest that Wollemi pine is an important potential source of compounds for the control of ARG and wild radish in winter crops.