美国工业废水预处理制度实施经验及对我国的启示

美国工业废水预处理制度对工业废水间接排放管控成效显著,主要特点包括:明确划分各实施主体的责任,形成全过程有效监管机制;预处理标准以基于技术和基于水质为双重约束;对工业用户实施重点分类管理,细化工业用户合规要求;授权公共污水处理厂直接管控工业用户,提高制度执行效率;注重污染源头控制,鼓励废水和污泥回收利用。对我国启示如下:健全我国工业废水预处理制度体系,强化纳管企业主体责任;在污水处理厂规划设计阶段,开展工业废水来源调查,编制纳管企业名单;在污水处理厂运行管理阶段,开展进水水质跟踪评估,建立污染负荷溯源机制;加大对工业废水间接排放的监督执法力度。     

Prenatal diagnosis using interphase fluorescence in situ hybridization (FISH): 2-year multi-center retrospective study and review of the literature

Since 1993, the position of the American College of Medical Genetics (ACMG) has been that prenatal interphase fluorescence in situ hybridization (FISH) is investigational. In 1997, the FDA cleared the AneuVysion^® assay (Vysis, Inc.) to enumerate chromosomes 13, 18, 21, X and Y for prenatal diagnosis. Data is presented from the clinical trial that led to regulatory clearance (1379 pregnancies) and from retrospective case review on 5197 new pregnancies. These studies demonstrated an extremely high concordance rate between FISH and standard cytogenetics (99.8%) for specific abnormalities that the AneuVysion assay is designed to detect. In 29 039 informative testing events (6576 new and 22 463 cases in the literature) only one false positive (false positive rate=0.003%) and seven false negative results (false negative rate=0.024%) occurred. A historical review of all known accounts of specimens tested is presented (29 039 using AneuVysion and 18 275 specimens tested with other probes). These performance characteristics support a prenatal management strategy that includes utilization of FISH for prenatal testing when a diagnosis of aneuploidy of chromosome 13, 18, 21, X or Y is highly suspected by virtue of maternal age, positive maternal serum biochemical screening or abnormal ultrasound findings. Copyright © 2001 John Wiley & Sons, Ltd.     

奎河水资源化工程采用水质指标的再讨论

分析了奎河水质变清含义、不同含义对奎河水质的要求，讨论了实现不同含义奎河水变清方案及其可行性和可靠性。作者认为，奎河水变清和全河道水质达标是一个很高的污染治理目标，需要通过对奎河污染控制系统的不断研究改进，水质指标的逐步提高才能逐渐逼近这一目标。     

某省高危含砷爆炸物污染农田评价及分布研究

利用不同的评价标准和方法评价了吉林省某地含砷高危爆炸物造成的砷污染,同时借助GIS软件绘制了砷污染指数分布图。结果表明:以土壤环境背景值的上限值为评价标准,平均污染累积指数为2.61,最大为65.38,约57.38%的土壤受到人为外源砷的干扰;以(GB 15618-2008)中砷的二级标准作为评价标准,平均污染指数为1.01,最大污染指数达15.27,超标率为23.87%,表明该区存在严重的砷污染;地累积指数污染评价结果也表明该地存在明显的外源砷污染,受到污染的比例达41.57%;3种评价方法结果基本一致。污染指数分布表明,该地重污染区集中在中部区域,并形成了一个西北-东南方向分布的污染带。     

油品脱酸工艺研究进展

综述了国内外油品脱酸技术发展历程和研究现状,分析了各种技术工艺的优点和不足,随着环保、节能减排思想的深入,新的绿色脱酸分离技术将是以后发展的主要趋势。     

Removal of natural organic matter by cationic hydrogel with magnetic properties

Magnetic cationic hydrogel (MCH) was synthesized, and its removal efficiency and mechanisms in regard to natural organic matter (NOM, represented by humic acid and fulvic acid) from the aqueous environment were studied. The effects of time, adsorbent dosage, initial pH, ionic strength, background ions, and NOM types were also investigated. MCH was characterized and found to have a strong magnetic character, yielding an extra advantage for recycling and reuse. Batch studies showed that the removal of Aldrich humic acid (AHA) by MCH was effective. The main mechanism for the removal of NOM is believed to be due to electrostatic interaction. NOM with larger molecular weight tended to be preferentially removed. Solutions with low pH, high ionic strength, and background electrolytes containing calcium, sulfate and bicarbonate were unfavorable for AHA removal. The adsorption-desorption of MCH was evaluated in three cycles, and demonstrated high regeneration rates.     

High-fluoride groundwater

Fluoride (F^???) is essential for normal bone growth, but its higher concentration in the drinking water poses great health problems and fluorosis is common in many parts of India. The present paper deals with the aim of establishment of facts of the chemical characteristics responsible for the higher concentration of F^??? in the groundwater, after understanding the chemical behavior of F^??? in relation to pH, total alkalinity (TA), total hardness (TH), carbonate hardness (CH), non-carbonate hardness (NCH), and excess alkalinity (EA) in the groundwater observed from the known areas of endemic fluorosis zones of Andhra Pradesh that have abundant sources of F^???-bearing minerals of the Precambrians. The chemical data of the groundwater shows that the pH increases with increase F^???; the concentration of TH is more than the concentration of TA at low F^??? groundwater, the resulting water is represented by NCH; the TH has less concentration compared to TA at high F^??? groundwater, causing the water that is characterized by EA; and the water of both low and high concentrations of F^??? has CH. As a result, the F^??? has a positive relation with pH and TA, and a negative relation with TH. The operating mechanism derived from these observations is that the F^??? is released from the source into the groundwater by geochemical reactions and that the groundwater in its flowpath is subjected to evapotranspiration due to the influence of dry climate, which accelerates a precipitation of CaCO₃ and a reduction of TH, and thereby a dissolution of F^???. Furthermore, the EA in the water activates the alkalinity in the areas of alkaline soils, leading to enrichment of F^???. Therefore, the alkaline condition, with high pH and EA, and low TH, is a more conducive environment for the higher concentration of F^??? in the groundwater.     

An integrated approach for spatio-temporal variability analysis of wetlands: a case study of Abaya and Chamo lakes, Ethiopia

Starting with the intensification of irrigation activities in the beginning of 1980s in Abaya and Chamo lakes area, the decreasing water inflow to the lakes caused denudation of the wetlands. The ecological situation in the lake region changed significantly during last four decades. The lakes and associated wetlands change have been studied using Landsat MSS (1973), Landsat TM (1986), and Ladsat ETM (2000) satellite imagery. Along with satellite imagery, other hydro-meteorological data were collected and hydro-meteorological data analyses were done to assess the variability of wetlands. From these data, lakes morphometric property estimation at different time series and water balance analysis for both lakes were done. Wetlands are mapped from the TCT image and these maps are subject to change detection to see the temporal and spatial variability of the wetlands. Moreover, the lake-morphometric area and volume variation have been studied. The result showed that between 1986 and 2000, a significant reduction has been observed but lesser than the previous decades (6.4 km(2)). The identified reason behind this change is that the free settlement and shoreline cultivation of the wetlands causing the soil erosion and eventually adds the sediment to the wetlands.     

Organic waste streams as feedstock for the production of high volume-low value products

Environmental Science and Pollution Research - Valorisation of organic wastes to produce industrially relevant commodity products is a sustainable, cost-effective and viable alternative providing a...     

Transformation and fate of urea in pit-toilet blackwater after discharge to environment

Environmental Science and Pollution Research - Studies on urea transformation reactions in blackwater are limited as urea rapidly hydrolyses under anaerobic condition. Since ammonium content of...