A new design of groundwater sampling device and its application

Compounds in the atmosphere contaminate samples of groundwater. An inexpensive and simple method for collecting groundwater samples is developed to prevent contamination when the background concentration of contaminants is high. This new design of groundwater sampling device involves a glass sampling bottle with a Teflon-lined valve at each end. A cleaned and dried sampling bottle was connected to a low flow-rate peristaltic pump with Teflon tubing and was filled with water. No headspace volume was remained in the sampling bottle. The sample bottle was then packed in a PVC bag to prevent the target component from infiltrating into the water sample through the valves. In this study, groundwater was sampled at six wells using both the conventional method and the improved method. The analysis of trichlorofluoromethane（ CFC-11 ） concentrations at these six wells indicates that all the groundwater samples obtained by the conventional sampling method were contaminated by CFC-11 from the atmosphere. The improved sampling method greatly eliminated the problems of contamination, preservation and quantitative analysis of natural water.     

传统增长质疑

传统增长质疑ＣｈａｌｌｅｎｇｉｎｇＴｒａｄｉｔｉｏｎａｌＧｒｏｗｔｈ￥ＴｈｏｒｂｊｏｈｎＢｅｒｎｔｓｅｎＡｂｓｔｒａｃｔ：Ｔｏｄａｙ，ｓａｖｉｎｇｔｈｅｐｌａｎｅｔｉｓａｂｏｕｔｒｅｄｅｆｉｎｉｎｇｏｕｒｄｅｖｅｌｏｐｍｅｎｔｍｏｄｅｌｓ．Ａｓｗｅｋ...     

SO2污染对小鼠骨髓细胞微核的诱发作用

在SO2吸入慢性染毒条件下,小鼠骨髓嗜多染红细胞（PCE）的微核细胞率与微核率均显著增加,且雌雄差异显著。结果也表明,SO2对阳性致突变剂乌拉坦航发微核的作用有显著抑制效应。本研究模拟SO2空气污染,从整体水平直接证实了SO2是哺乳类细胞染色体断裂剂、SO2与阳性致突变剂的联合作用是复杂的结论。     

超越价值:生物多样性与思想自由

各种环境因素的协同作用已经导致保护运动在解释保护运动的基本信念时尤其缺乏信心。“反对派”行动主义者以为他们的论据是得到证实的，而“制度派”战术主义者倾向于采取他们并不赞同的功利主义的或经济的观点。根据现有的证据，在几百年以后，这个星球上主要的自然区域将基本消失，人类的生活质量将会受到极大的威胁。一种更可靠的观点认为：自然界是人类体验自由(这也是一种精神环境)的能力中不可或缺的一部分。这一观点将改变我们对待自然环境的方式，也关乎今后生物多样性长期生存的前景。     

铬的溶剂萃取(评论)

<正> 铬的溶液中主要以两种氧化态即Cr(Ⅲ)与Cr(Ⅵ)存在。第一种较稳定,并有形成惰性络合物的倾向。在非络合剂阴离子(如ClO_4~-)存在的情况下,Cr(Ⅲ)离子以Cr(H_2O)_6~(3+)及其水解产物的形式存在,在不同的pH值时,占优势的是Cr(H_2O)_5OH~(2+)     

Petroleum waste biodegradation with porous biomass support system (PBSS) on rotating biological contactor

A laboratory scale study was conducted to assess the feasibility of the new coupling of rotating biological contactor (RBC) plus porous biomass support system (PBSS) using polyurethane foam as porous support media to biodegrade petroleum refinery wastewater. Polyurethane foam was attached on disks of two four-stage laboratory scale cascade connected RBC units.The two RBC units were operated simultaneously at different but constant, flowrates giving hydraulic loading rates of 0.01, 0.02, 0.03, 0.04 m3/m2/d in two runs keeping the same rotational speed 10 r/min throughout. Organic loading was a less controllable factor in this study.For all of the hydraulic loadings, it was found that the removal efficiency of total chemical oxygen demand (TCOD) and oil were above 80 percent. Ammonia nitrogen and phenol removal were above 90 and 80 percent respectively. The maximum biomass concentration within polyurethane foam was about 30 g/m2 in the first stage for 0.03 m3/m2/d hydraulic loading.The results show that t     

Status of air pollution in Beijing

A study has been made on elements organic constituents, TSP, SO2,NO2 of atmospheric pollutants in Beijing. 17 elements, and some PAHs, e. g. B(a)P, B(b, j, k)P, and B(g, h, i)P, in airborne particles by X-ray fluorescence spectroscopy and HPLC, GC/MS, have been determined respectively. It has been shown that the elements Pb, Zn, S and Cu were more enriched in fine particles and different valence states of sulfur at various sites. It was found that the concentrations of S6+ and S2-were more than 85% and less than 15% of the total sulfur respectively. Concentrations of major PAHs and sulfur-containing compounds increased in winter and in urban area. High values for Pb and Zn in city, Fe and Mn at industrial area and Cu, Al rural sites were obtained respectively. This implies the functions of different elemental sources of various sites. Thus, elements can be from distingushed anthropogenic and natural sources.The main contribution of SO2 was found of to have same seasonal variation as the anthropogenic el     

厌氧活性炭滤池对酚类的处理

绪言酚类化物(苯的一元羟基衍生物)是炼焦厂、煤气化厂、炼油厂、石油化工、溶剂、炸药生产、玻璃纤维制造以及飞机维修等工业废水的主要成分。Mazur以及 Ganczarczyk 和 ELion发现炼焦废水用活性污泥处理,其中酚的去除率超过99％。Capestany 等人报导了用活性污泥处理高浓度含酚废水的类似研究结果。氧化塘、污泥曝气湖和氧化塔据报导对低浓度含酚废水处理或对进一步降低活性污泥厂出水中的酚含量是有效的。一般说来,各种好氧生化处理法对含酚废水处理是有效的,其结果使废水的化学需氧量(COD)、总有机炭(TOC)