Tissue distribution and elimination of trichlorobenzenes in the rat

The tissue distribution and excretion of three trichlorobenzene isomers (TCB) were investigated in the rat. Single doses of TCBs were administered orally to groups of 5 fasted rats at 10 mg/kg body weight. Serial sacrifices were carried out and the radioactivity contents were determined in tissues and blood. For all three TCB isomers, radioactivity appeared in the blood and tissues at 0.5 h, and peaked around 2-4 h after dosing. Fat, skin, and liver had high concentrations of the parent compound while kidney and muscle had high levels of metabolites. Elimination of TCB from tissues and blood can best be described by a two-compartmental open pharmacokinetic model. The terminal half-lives were 145, 93 and 68 h for 1,2,3-, 1,2,4 and 1,3,5-TCB isomer respectively. Ninety-five percent of the administered 1,2,3- and 89% of the 1,3,5-isomers were eliminated within 48 h in the urine and feces with the former being the major route.     

SBR技术在有机农药废水处理中的应用

采用中和微碱解－厌氧水解－SBR好氧生化工艺处理氧化乐果，久效磷有机农药废水，与国内同类其它处理技术相比较，其COD、BOD5、P等主要污染物去除率以及处理成本，工程投资，占地面积等项技术经济指标优势明显，可在同行业中推广应用。     

长链烯酮不饱和度温标研究进展

长链烯酮不饱和度温标是古温度研究的重要替代指标。介绍了小样量、低长链烯酮样品的分析方法 ,长链烯酮的来源、分布 ,长链烯酮的不饱和度与温度的关系及其在古环境研究中的应用。介绍海洋中长链烯酮研究最新进展的同时 ,着重阐述了湖泊中长链烯酮研究现状及存在的主要问题。     

开展HSE管理体系认证促进HSE管理的推广和应用

在企业按照标准建立HSE管理体系的同时，主管行业应该同时进行HSE管理体系的认证，以逐步完善企业HSE管理体系，改变企业形象，促进企业真正按照HSE管理体系开展工作。     

土壤蒸发研究及对旱灾防治的意义

土壤蒸发是地表能量与水分平衡的重要组成部分.本文综述了几十年来土壤蒸发研究基本理论及发展过程,并提出了对于旱灾防治的意义.     

Adsorption and partition of benzo(a)pyrene on sediments with different particle sizes from the Yellow River

Experiments have been carried out to study the sorption of Benzo(a)pyrene(Bap) on sediment particles from the Yellow River using a batch equilibration technique. Effects of particle size on the adsorption and partition of Bap were investigated with the particle content of 3 g/L. Several significant results were obtained from the study. (1) Isotherms of Bap could be fitted with the dual adsorption-partition model under different particle sizes, and the measured value of the adsorption and partition was in agreement with the theoretical value of the dual adsorption-partition model. (2) When the particle diameter was d ⩾ 0.025 mm, the adsorption was predominant in the sorption of Bap, which accounted for 68.7%–82.4% of the sorption. For the particles with the size of 0.007 mm⩽d<0.025 mm, the adsorption was predominant when the equilibrium concentration of Bap was 0–8.87 μg/L in the water phase; and the partition was predominant when the equilibrium concentration of Bap was higher than 8.87 μg/L in the water phase. When the particle diameter was d<0.007 mm, the partition was predominant. (3) On the point of particle size, the contribution of adsorption to sorption followed the order: “d⩾0.025 mm”>“0.007 mm ⩽d<0.025 mm” >“d<0.007 mm”. (4) The partition coefficients of Bap in solids with different particle sizes were linearly correlated with the organic content, and the K _oc of Bap was about 1.26 × 10⁵ (L/kg). Translated from Acta Scientiae Circumstantiae, 2006, 26(2): 269–274 [译自: 环境科学学报]     

应用pH—ORP计自动控制液氯氧化含氰废水

排放量较大的含氰电镀废水,在碱性氯化法处理中以液氯为氧化剂,用PH—ORP计自动控制反应条件和反应终点。该方法自动化程度高,处理效果较好,运行费用低。     

净化汽车尾气的三效催化剂

在我国，汽车尾气对大气的污染日趋严重，使用三效催化剂净化汽车尾气势在必行。介绍了几种主要的三效催化剂及其应用情况。     

The direct photolysis and photocatalytic degradation of alachlor at different TiO2 and UV sources

Direct photolysis and photocatalytic degradations of alachlor, a widely used herbicide, were studied using three different monochromatic UV lamps (254, 300 and 350 nm) and two TiO(2) sources. Both the direct photolysis and photocatalytic degradations of alachlor follow pseudo-first-order decay kinetics. TiO(2)-P25 was found to be an effective photocatalyst compared to TiO(2)-BDH. The direct photolysis of alachlor was dominant at 254 nm even if TiO(2) was present in the solution. Among the three UV wavelengths used, the highest photocatalysis quantum yield was obtained at 300 nm. The photocatalytic degradation rate of alachlor increased with the dosages of TiO(2), but an overdose of TiO(2) would retard the reaction due to light attenuation. Photocatalytic reactions were slightly enhanced in an alkaline medium, and the different proton sources causing various degrees of rate retardation were due to the presence of the corresponding counter anions. This effect was diminished at a later stage after the reaction intermediates were formed.     

The study of lag phase and rate improvement of TCE decay in UV/surfactant systems

The photodegradation of trichloroethene (TCE) in surfactant micelles was investigated. The decay of TCE was studied in the Rayonet RPR-200 merry-go-round photoreactor, at 253.7 nm monochromatic ultraviolet (UV) lamps, in the presence of surfactants. Surfactants are used as additional hydrogen sources to improve the photodegradation rates of TCE. About three times the rate increment is observed in the presence of Brij 35 surfactant micelles than in water alone. The increasing concentrations of H+ and Cl- indicate that they are the final products of TCE photodegradation (i.e. photodechlorination is the dominant mechanism in this system). A lag phase is observed at the beginning of the degradation, but the duration of the lag phase is apparently reduced as the initial pH increases. Because the overall decay of TCE is also found faster at higher pH levels, it is suggested that the free radical reaction is dominant at high pH levels, and the formation of lag phases is mainly due to the deficiency of free radicals at lower pH levels. The photodecomposition of TCE in surfactant micelles is also proven to be a clean and effective process. It generates no chlorinated by-products or intermediates during the process, and TCE is fully decomposed within a reasonable time.