Concentrations of cyclic volatile methylsiloxanes in biosolid amended soil,influent, effluent,receiving water,and sediment of wastewater treatment plants in Canada

A comprehensive surveillance program was conducted to determine the occurrence of three cyclic volatile methylsiloxanes (cVMS) octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in environmental compartments impacted by wastewater effluent discharges. Eleven wastewater treatment plants (WWTPs), representative of those found in Southern Ontario and Southern Quebec, Canada, were investigated to determine levels of cVMS in their influents and effluents. In addition, receiving water and sediment impacted by WWTP effluents, and biosolid-amended soil from agricultural fields were also analyzed for a preliminary evaluation of the environmental exposure of cVMS in media impacted by wastewater effluent and solids. A newly-developed large volume injection (septumless head adapter and cooled injection system) gas chromatography – mass spectrometry method was used to avoid contamination originating from instrumental analysis. Concentrations of D4, D5, and D6 in influents to the 11 WWTPs were in the range 0.282–6.69 μg L⁻¹, 7.75–135 μg L⁻¹, and 1.53–26.9 μg L⁻¹, respectively. In general, wastewater treatment showed cVMS removal rates of greater than 92%, regardless of treatment type. The D4, D5, and D6 concentration ranges in effluent were <0.009–0.045 μg L⁻¹, <0.027–1.56 μg L⁻¹, and <0.022–0.093 μg L⁻¹, respectively. The concentrations in receiving water influenced by effluent, were lower compared to those in effluent in most cases, with the ranges <0.009–0.023 μg L⁻¹, <0.027–1.48 μg L⁻¹, and <0.022–0.151 μg L⁻¹ for D4, D5, and D6, respectively. Sediment concentrations ranged from <0.003–0.049 μg g⁻¹ dw, 0.011–5.84 μg g⁻¹ dw, and 0.004–0.371 μg g⁻¹ dw for D4, D5, and D6, respectively. The concentrations in biosolid-amended soil, having values of <0.008–0.017 μg g⁻¹ dw, <0.007–0.221 μg g⁻¹ dw, and <0.009–0.711 μg g⁻¹ dw for D4, D5, and D6, respectively, were lower than those in sediment impacted by wastewater effluent in most cases. In comparison with the no-observed-effected concentrations (NOEC) and IC50 (concentration that causes 50% inhibition of the response) values, the potential risks to aquatic, sediment-dwelling, and terrestrial organisms from these reported concentrations are low.     

Inter-laboratory exercise on steroid estrogens in aqueous samples

An inter-laboratory comparison exercise was organized among European laboratories, under the aegis of EU COST Action 636: “Xenobiotics in Urban Water Cycle”. The objective was to evaluate the performance of testing laboratories determining “Endocrine Disrupting Compounds” (EDC) in various aqueous matrices. As the main task three steroid estrogens: 17α-ethinylestradiol, 17β-estradiol and estrone were determined in four spiked aqueous matrices: tap water, river water and wastewater treatment plant influent and effluent using GC-MS and LC-MS/MS. Results were compared and discussed according to the analytical techniques applied, the accuracy and reproducibility of the analytical methods and the nature of the sample matrices. Overall, the results obtained in this inter-laboratory exercise reveal a high level of competence among the participating laboratories for the detection of steroid estrogens in water samples indicating that GC-MS as well as LC-MS/MS can equally be employed for the analysis of natural and synthetic hormones.     

火电厂废水零排放技术的研究

讨论了火电厂各种废水的处理技术，结合我国的实际情况，探讨适用的火电厂零排放技术。     

印染废水反渗透处理

通过分析反渗透原理进而提出将反渗透法用于印染废水处理，根据印染废水的特征和水的渗透机理，提出了半透膜的选择和反渗透系统设计。     

UASB-AS工艺处理啤酒废水

采用UASB－AS组合工艺处理啤酒废水，其UASB单元可降解废水中大部分有机物，减轻了后续好氧工艺的负荷，也降低了运行能耗与费用；AS工艺可确保系统出水的达标排放。实践表明，UASB－AS系统具有运行稳定、费用低、抗冲击负荷强等优点。     

长江常熟段排污口布置方案数值模拟论证研究

为合理确定常熟氟化工项目排污口布置方案，针对长江常熟段水环境特征，尤其是复杂的水地下形和水流流场，建立为较为准确和实用的平面二维水流水质耦合数学模型，应用剖开算子法模拟计算了3套排污方案对重点保护水域影响程序度和范围，并从水流场，水质影响评价，技术经济多角度对方案进行了比较论证，最终推荐污水江中排放的方案，为项目的工程设计和环境管理提供了科学依据。     

Collective action: an alternative institutional arrangement for reducing water pollution in an industrial estate in India

This study explores the possibility of collective action as an alternative option for reducing water pollution for a cluster of small-scale industries. A case study of the Nandesari Industrial Estate in Gujarat, India, demonstrates the roles played by different agents, such as affected parties, polluters, non-governmental organizations, regulators and the court. The study empirically estimates the 'benefits' and 'costs' of water pollution abatement for a cluster of 250 small-scale industries at Nandesari, and uses these estimates for a social cost-benefit analysis. Benefits are estimated using the contingent valuation method, with a 'willingness to accept' format for the rural areas, and a 'willingness to pay' format for the urban area of the nearby Vadodara city. The article considers costs of command and control, market-based solutions and the option of common effluent treatment as alternative scenarios. It discusses how collective action and joint abatement at a common effluent treatment plant (CETP) by the 250 industries efficiently comply with the State Pollution Control Board norms, which had not been possible for the factories acting individually over the last 20 years. Finally, a detailed social cost-benefit analysis has been undertaken to estimate the net present social benefits with and without CETP. The cost-benefit analysis shows the economic advantage and social desirability of 'collective action' (joint treatment with CETP institutional arrangement) for water pollution abatement with respect to all possible scenarios comprising shadow prices of investment, foreign exchange, unskilled labour and equity considerations.     

氰化法提金废水治理技术

本文介绍了我国氰化法提金废水的产生及对水环境造成的污染。根据氰化嘛不的基本性质，评述了国内外氰化废水的处理技术，工艺流程和研究成果，同时指出了这些方法的应用范围及局限性。     

Optimizing Liquid Effluent Monitoring at a Large Nuclear Complex

Effluent monitoring typically requires a large number of analytes and samples during the initial or startup phase of a facility. Once a baseline is established, the analyte list and sampling frequency may be reduced. Although there is a large body of literature relevant to the initial design, few, if any, published papers exist on updating established effluent monitoring programs. This paper statistically evaluates four years of baseline data to optimize the liquid effluent monitoring efficiency of a centralized waste treatment and disposal facility at a large defense nuclear complex. Specific objectives were to: (1) assess temporal variability in analyte concentrations, (2) determine operational factors contributing to waste stream variability, (3) assess the probability of exceeding permit limits, and (4) streamline the sampling and analysis regime. Results indicated that the probability of exceeding permit limits was one in a million under normal facility operating conditions, sampling frequency could be reduced, and several analytes could be eliminated. Furthermore, indicators such as gross alpha and gross beta measurements could be used in lieu of more expensive specific isotopic analyses (radium, cesium-137, and strontium-90) for routine monitoring. Study results were used by the state regulatory agency to modify monitoring requirements for a new discharge permit, resulting in an annual cost savings of US $223,000. This case study demonstrates that statistical evaluation of effluent contaminant variability coupled with process knowledge can help plant managers and regulators streamline analyte lists and sampling frequencies based on detection history and environmental risk.     

Design of Mass Exchange Network and Effluent Distribution System for effective water management

The environmental impact of industrial wastewater and higher cost of fresh water are the serious challenges faced by the process industries. It has led to the development of many new techniques to minimize fresh water consumption. Of the many approaches, which have been developed, the Water Source Diagram (WSD) is a flexible and dynamic alternative for the generation of different scenarios for the management of water networks with reduction in total consumption. In the present study WSD concept was coupled with water mains concept to mains simplify the piping network and reduce the cost. A new procedure was developed for integrating the effluent treatment processes to evolve Effluent Treatment Network. Example from literature having multi contaminants was considered. This simple procedure involving hand calculations will be a useful tool for process engineers to design water and effluent treatment networks. Also the WSD and ETN were combined to form an evolutionary WAMEN (Water Allocation and Mass Exchange Network) and the proposed WAMEN aims for minimum fresh water consumption.