Degradation kinetics and products of triazophos in intertidal sediment

This work presents taboratory studies on the degradation of triazophos in intertidat sediment. The overall degradations were found to follow the first-order decay model. After being incubated for 6 d, the percentage of degradations of triazophos in unsterilized and sterilized sediments were 94.5% and 20.5%, respectively. Between the temperatures of 15℃ and 35℃, the observed degradation rate constant（kob,d） enhanced as the incubation temperature increased. Triazophos in sediment degraded faster under aerobic condition than under anaerobic one. The water content of sediment had little influence on the degradation when it was in the range of 50%-100%. The values of kobsd decreased with increasing initial concentration of triazophos in sediment, which could result from the microorganism inhibition by triazophos. Four major degradation products, o, o-diethyl phosphorothioic acid, monoethyl phosphorothioic acid, phosphorothioic acid, and 1-phenyl-3-hydroxy-1, 2,4-triazole, were tentatively identified as their corresponding trimethylsilyl derivatives with a gas chromatography-mass spectrometer. The possible degradation pathway of triazophos in intertidal sediment was proposed. The results revealed that triazophos in intertidal sediment was relatively unstable and coutd be easily degraded.     

小头蓼(P.Microcephalum)对矿区铜的吸收积累研究

调查并分析云南省铜矿区的植物区系及土壤理化特性，发现小头蓼（P.Microcephalum）在云南省高海拔铜矿区生长旺盛，是该地区的优势植物种，小头蓼生长的土壤基质富含铜，其它养分条件适中，研究表明小头蓼具有较强的富集铜的能力；随土壤中铜含量的增加，植物根系铜含量也相应增加，但叶部铜含量变人与土壤铜含量之间无相关性，研究认为该植物具有对铜污染土壤的植物固定潜能。此外，还指出最适于小头蓼富集铜的土壤条件为土壤有机质1％－1.5％，土壤pH为中性。     

Kinetics of continuous biodegradation of pesticide organic wastewater by activated carbon-activated sludge

１ＩｎｔｒｏｄｕｃｔｉｏｎＮｏｖｅｌｂｉｏｌｏｇｉｃａｌａｃｔｉｖａｔｅｄｃａｒｂｏｎａｎｄａｃｔｉｖａｔｅｄｓｌｕｄｇｅｓｙｓｔｅｍｈａｓｓｈｏｗｎｉｔｓｅｆｅｃｔｉｖｅａｂｉｌｉｔｙｔｏｒｅｄｕｃｅＣＯＤｉｎｔｏｘｉｃｏｒｇａｎｉｃｗａｓｔｅｗａ...     

杭州市大气NOx来源及控制对策研究

采用定常高斯模式和Thlong程序建立NOx污染源强与大气NOx浓度间定量响应数值模型,计算了点源、面源和流动源等各类污染源对杭州市区各关心点NOx的平均贡献率,分别约为17%,17%和66%,其中市区机动车尾气贡献率高达50%左右,是首先要控制的污染源.同时提出NOx排放削减方案及实施后大气NOx质量改善状况,为环保管理部门削减NOx污染源提出供决策参考.     

湖泊水体中硫酸盐增高的环境效应研究

通过对高原３个硫酸盐浓度差异的湖泊沉积物水界面硫的形态分布、扩散通量和碎屑有机硫通量等估算，揭示了湖泊水体硫酸盐增加以后的环境效应和自然反馈机制．研究认为：水体向沉积物内部扩散和界面硫酸盐还原作用是高硫酸盐浓度水体硫酸盐的主要清除作用，随硫酸盐浓度的增加，它在水体清除硫酸盐作用的贡献逐渐增大，而低硫酸盐含量湖泊水体生物同化吸收作用是水体硫酸盐的主要清除机制，它在硫酸盐浓度不同的水体没有差异．     

Occurrence and congeners specific of poiychlorinated biphenyls in agricultural soils from Southern Jiangsu, China

A total of 198 agricultural soil samples were collected from Zhangjiagang and Changshu in Southern Jiangsu for analysis of 13 polychlorinated biphenyls (PCBs) in order to assess the levels of pollution, sources, area distribution, and potential risk for the environment. All methods were rigorously tested and an adequate quality control was ensured. Only one site had no PCBs residues, and the highest total PCBs concentration in the surface soils was 32.83 ng/g. The average concentration in all the soil samples was 4.13 ng/g, signaling low-level pollution. Tetra-, penta-, and hexa-chlorinated biphenyls were dominant species in soil samples, accounting for more than 75% ofΣPCBs in the soil samples. PCB118 was the most abundant congener in all the samples. The PCB118 was about 20% ofΣPCBs. The soil organic matter content showed only a weak correlation with the levels of all PCB congeners, in which a better correlation was noted for the more volatile lighter PCB congeners than for the heavier homologues. To a certain extent, the sources and land use seemed to influence the levels of PCBs.     

一种特殊形状制件的成形工艺

对弹匣前口板这种特殊形状制件成形工艺进行了讨论,找到了一种具有较高材料利用率,较高生产效率及简便易行的成形方法.     

楔横轧模具的铣削加工及其机床设计

根据楔横轧模具孔型及其加工成形的特点,对楔横轧模具大面积大螺距楔形提出了一种简单高效的铣削加工方法,并设计制造了楔横轧轧辊模具孔型加工专用机床——SDM机床。新设计的SDM机床投资小,可以加工直径为φ620 mm～φ1000mm的轧辊模具,加工导程最大可达469 mm,加工周期短,成本低,且大大降低了工人劳动强度。     

硫代磷酸二乙酯加热水解的研究

在二升高压釜中,氮气氛条件下研究了有机磷农药废水的主要污染物质——硫代磷酸二乙酯(浓度为100ppm)的水解动力学.运用气相色谱法,在pH2—4,温度140—190℃范围,得到不同条件下的一级反应速率常数k,获得pH、温度与反应速率常数的关系,并对硫化磷酸二乙酯的水解条件进行了讨论.     

区域环境质量综合评价的一种方法——Fuzzy概率法

本文应用Fuzzy概率原理,在对区域环境内各单项污染指标进行分级评价的基础上,考虑各单项污染指标在总体中的权重,并综合各单项污染指标的作用,给出区域环境内环境“总”质量的综合评价。