Mineralization of organic matter in water by u.v. radiation

The conditions for the optimum yield of carbon dioxide in the mineralization of organic matter in water were tested and the relative optimum procedure was outlined. Of all substances tested the greatest difficulties were encountered with the purine bases. Their quantitative mineralization was achieved only by the highest irradiation intensities and/or prolonged irradiation. An evident relationship of mineralization and pH was found in urea and thiourea. Adsorbtion of proteins on silica and glass apparatus was suppressed by phosphoric acid, but a correction of the amount of organic carbon recovered in the blank still had to be applied in protein rich samples.     

Determination of alkyl benzenesulfonate in water by u.v. method

Alkyl benzenesulfonates in water were determined by u.v. method.Alkyl benzenesulfonates in water were extracted by 1,2-dichloroethane as methylene blue complexes, and, after being isolated from methylene blue by washing with cone. hydrochloric acid, were extracted by water from 1,2-dichloroethane solution.Alkyl benzenesulfonate solutions were measured by absorbance at 222 nm. This band is characteristic of benzene and alkyl benzenesulfonates separated from other anionic surfactants completely.     

Observations on the estimation of total organic carbon from u.v. absorbance for an unpolluted stream

The concentration of total organic carbon in unpolluted stream water may be estimated from measurement of absorbance at 250 nm. However, unless allowance is made for the change in the composition of this organic matter under diverse flow conditions, the estimation is subject to serious systematic errors, particularly at low carbon concentrations. Grouping data according to flow at time of sampling leads to a considerable improvement in the accuracy of the estimation, but requires the use of three regression equations. The resulting procedure is then, however, valid under a wide range of flow conditions.     

Treatability evaluation of general organic matter. Matrix conception and its application for a regional water and waste water system

For the evaluation of the behaviors of general organic compounds in a regional water and waste water system and individual or combined water treatment processes, the authors have proposed to use some water quality indices in connection with scale grouping of organic compounds.The treatability of various types of treatment processes such as biological treatment, chemical coagulation and carbon adsorption were well evaluated with three comprehensive water quality indices such as TOC. TOC/E260 (absorbance at 260 nm) and E220 (absorbance at 220 nm) connected with the gel-chromatographic grouping after a water quality matrix conception.     

谈污染场地的评价体系

结合我国污染场地评价体系研究的现状,对污染场地的类型进行了分类,从污染识别、污染确认、风险评估三个阶段对污染场地的评价体系进行了分析,并提出了相应的建议和意见。     

u.v.-DOC characterisation of pulp and paper bleach effluents

Flocculation characterisation of both sulphite and kraft bleach effluents, has been studied using Al salts.Plots of u.v. absorbance vs DOC obtained in a sequential flocculation procedure, produce a straight line and allow an accurate estimation of the non-u.v. absorbing DOC in the effluent to be made. These plots may be useful to estimate DOC loadings likely to be encountered when designing effluent treatment systems.     

物料搅拌加水自动控制系统

本文研究的自动加水控制系统,旨在改变制砖及相关行业产品成型前物料搅拌加水环节人工操作的落后状况,使工艺更具科学性,从而提高行业的技术档次。     

Influence of temperature and u.v. light on disinfection with ozone

An inactivation study was performed with ozone in two laboratory-scale, continuous flow systems to determine the effects of temperature and u.v. light on the survival of Mycobacterium fortuitum, a potential microbial indicator for disinfection efficiency. Four temperatures were investigated in the range of 9–37°C. It was determined that a higher degree of inactivation occurred with ozone at elevated temperatures. The activation energy for M. fortuitum was found to be 18.3 kcal.When u.v. light was employed as a catalyst with ozone disinfection, there was no apparent increase in the degree of inactivation of M. fortuitum in either the clean system (deionized water-phosphate buffer) or secondary wastewater effluent. However, u.v. light in itself exerted a strong disinfecting effect.     

A clay-vesicle system for water purification from organic pollutants

Vesicle-clay complexes in which positively charged vesicles composed of didodecyldimethylammonium bromide (DDAB) were adsorbed on montmorillonite removed efficiently anionic (sulfentrazone, imazaquin) and neutral (alachlor, atrazine) pollutants from water. These complexes (0.5% w:w) removed 92-100% of sulfentrazone, imazaquin and alachlor and 60% of atrazine from a solution containing 10mg/L of it. A synergistic effect on the adsorption of atrazine was observed when all pollutants were present simultaneously (30 mg/L each), its percentage of removal being 85.5. Column filters (18 cm) filled with a mixture of quartz sand and vesicle-clay (100:1, w:w) were tested. For the passage of 1L (25 pore volumes) of a solution including all the pollutants at 10mg/L each, removal was complete for sulfentrazone and imazaquin, 94% for alachlor and 53.1% for atrazine, whereas removal was significantly less efficient when using activated carbon. A similar advantage of the vesicle-clay filter was observed for the capacities of removal.     

远距离供水工程自动化系统

结合某供水工程自动化系统结构，对其系统结构概况进行了阐述，介绍了一种适合远距离供水自动化系统的实施模式，并对全线自动化控制的功能作了探讨，提出了一些控制策略。     

城市给水工程自动化系统设计

城市给水工程自动化系统的建设有其必要性；目前，国内给水自控系统采用最多的是由工业计算机＋PLC＋自动化仪表组成的多级分布式计算机测控管理系统；介绍了给水工程自动化系统构成原理和设计实施方案，阐述了企业信息网络概念、软件组成、功能以及自动化设备选型原则；展望了给水自动化发展方向及应用前景。     

南海饮用水水源突发性污染应急处理系统的研发和建立

针对水源突发性污染频发的现状,开发和建立了南海饮用水水源突发性污染应急处理系统。在对北江水源地存在的污染物进行调查分析并确定目标污染物的基础上,研究了目标污染物的应急去除技术,建立水源水质预警系统和水厂应急强化处理系统。介绍了项目实施的技术思路以及取得的主要技术成果,可为同行业其他企业提供参考。     

大丰市自来水公司原水水质自动监测系统介绍

为了实时、准确地监测通榆河的水质及其变化状况,提供实时水质监测数据及预警信息,以便及时启动应急预案,大丰市自来水有限公司建立了原水水质自动监测系统。通过利用先进的水质在线分析仪器,采用数据采集、通讯传输、远程监控等技术,实现了实时监测原水水质,并通过多种远程通讯方式将数据传输至中控室及各级数据共享终端,满足了供水安全保障的需求。     

Rationale for a water pollution code

A water pollution code must quantitatively express the amount and locations of allowable waste discharges. To do this, each of the steps leading to the decision on allowable waste discharge must be defined and quantified.

Six of these steps were discussed in Part I of this analysis. The seventh step, which will be discussed here, concerns the assessment of the costs and benefits associated with different levels of water quality, and the selection of a water quality standard with reference to prevailing community attitudes. The procedure for making this assessment is discussed. The development of a social welfare function using the cost benefit approach and also the relative preferences approach, is described, and the selection of the appropriate water quality standard, using the social welfare function, is discussed.

The final step in deciding allowable waste discharges, which concerns the selection and application of the most acceptable and efficient waste control strategy, will be considered in Part III of this analysis.     

Rationale for a water pollution code part 1: the waste system and the natural system

A water pollution code must quantitatively express the amount and locations of allowable waste discharge. To do this each of the steps leading to the decision on allowable waste discharge must be defined and quantified. Six of the steps are defined in this report and techniques for quantitatively representing them are discussed. The movement of materials from man's environment back into the natural environment is described by five steps: waste generation, waste treatment, waste transport, waste interaction and waste decay. The sixth step discussed in this report represents the impact of the wastes on the natural system. Two further steps in deciding allowable waste discharges will be treated in Parts II and III of this paper which will appear in the next two issues of the Journal.     

Decision support system for the evaluation of urban air pollution control options: Application for particulate pollution in Thessaloniki, Greece

Development of strategies to control urban air pollution is a complex and multi-disciplinary process involving a wide range of scientists with different expertise and interests. This paper presents an integrated assessment methodological scheme for the evaluation of air pollution control measures that are put forward in order to reduce sufficiently air pollution levels in urban areas. Forming long-term, efficient air pollution control strategies requires knowledge of the costs associated with their implementation, the emission inventories and emission reductions to be achieved, as well as the concentration variations that represent air quality levels in the area examined. In contrast to the majority of the currently employed assessment approaches, the presented scheme enables the evaluation of any proposed air pollution control option in terms of its combined impact on air quality and social welfare, by correlating economic and health impact assessment issues. The approach presented in this paper brings together air quality modelling and mathematical programming techniques and provides a decision support system for the determination of optimal bundles of air pollution control options according to the particular features and needs of the areas examined. Both cost-effectiveness and cost–benefit approaches are taken into account in order to put the problem on the basis of economic efficiency from a societal perspective. The methodology is implemented for the case of Thessaloniki, Greece, which is selected on the grounds that the area is considered as one of the most polluted—if not the most polluted—cities within Europe, especially with respect to airborne particles.     

Bioanalytical tools for the evaluation of organic micropollutants during sewage treatment, water recycling and drinking water generation

A bioanalytical test battery was used for monitoring organic micropollutants across an indirect potable reuse scheme testing sites across the complete water cycle from sewage to drinking water to assess the efficacy of different treatment barriers. The indirect potable reuse scheme consists of seven treatment barriers: (1) source control, (2) wastewater treatment plant, (3) microfiltration, (4) reverse osmosis, (5) advanced oxidation, (6) natural environment in a reservoir and (7) drinking water treatment plant. Bioanalytical results provide complementary information to chemical analysis on the sum of micropollutants acting together in mixtures. Six endpoints targeting the groups of chemicals with modes of toxic action of particular relevance for human and environmental health were included in the evaluation: genotoxicity, estrogenicity (endocrine disruption), neurotoxicity, phytotoxicity, dioxin-like activity and non-specific cell toxicity. The toxicity of water samples was expressed as toxic equivalent concentrations (TEQ), a measure that translates the effect of the mixtures of unknown and potentially unidentified chemicals in a water sample to the effect that a known reference compound would cause. For each bioassay a different representative reference compound was selected. In this study, the TEQ concept was applied for the first time to the umuC test indicative of genotoxicity using 4-nitroquinoline as the reference compound for direct genotoxicity and benzo[a]pyrene for genotoxicity after metabolic activation.The TEQ were observed to decrease across the seven treatment barriers in all six selected bioassays. Each bioassay showed a differentiated picture representative for a different group of chemicals and their mixture effect. The TEQ of the samples across the seven barriers were in the same order of magnitude as seen during previous individual studies in wastewater and advanced water treatment plants and reservoirs. For the first time a benchmarking was performed that allows direct comparison of different treatment technologies and covers several orders of magnitude of TEQ from highly contaminated sewage to drinking water with TEQ close or below the limit of detection. Detection limits of the bioassays were decreased in comparison to earlier studies by optimizing sample preparation and test protocols, and were comparable to or lower than the quantification limits of the routine chemical analysis, which allowed monitoring of the presence and removal of micropollutants post Barrier 2 and in drinking water. The results obtained by bioanalytical tools were reproducible, robust and consistent with previous studies assessing the effectiveness of the wastewater and advanced water treatment plants. The results of this study indicate that bioanalytical results expressed as TEQ are useful to assess removal efficiency of micropollutants throughout all treatment steps of water recycling.     

Uncertainty and planning for water pollution control

This paper addresses the problem of planning the construction and expansion of a sewage treatment facility operating on a river. It is argued that any model for solution of the problem must take explicit account of the many uncertainties with which the problem is fraught. An expository model of this kind is constructed and its solution discussed.     

地铁高压细水雾系统与相关专业接口分析

根据已有的工程实例和相关国家规范规定,系统全面地对上海市地铁地下车站的高压细水雾系统的设计接口进行了总结和探讨,以期对其他城市相关地铁工程设计提供借鉴和参考。     

Removal of organic matter from water by PAC/UF system

The laboratory-scale ultrafiltration (UF) experiments were conducted to determine the effect of the presence of powdered activated carbon (PAC) on the UF process performance, in terms of flux decline and the possibilities of membranes cleaning during backwashing. Poly(vinylidene fluoride) membranes formed by the phase inversion technique were used in the UF experiments. A model solution was prepared as a mixture of humic acids (HA) and phenol in concentration of 10 and 1 mg l(-1), respectively. Commercial powdered activated carbons CWZ 11 and CWZ 30 (Gryfskand Sp. z o. o., Hajnówka, Poland) were used as the adsorbents. PAC dosage was in the range of 10-100 mg PAC l(-1). The process was carried out in the cross-flow system. It was found that PAC addition to the distilled water leads to a small drop in the permeate flux, regardless of PAC dose and its type. Although PAC particles are too large to block the membrane pores inside, they deposit on the membrane surface and partially can plug the surface pores. The experimental results demonstrate that the backwashing process applied in combined PAC/UF system was especially effective when PAC dosages were <20mg PAC l(-1). However, a similar permeate flux was maintained for all carbon dosages used and reached the value of about 1 m3 m(-2) d(-1). Moreover, no further drop in the permeate flux for PAC addition to the solution containing foulants (HA) was observed. Effectiveness of the removal of HA and phenol from the model solutions was also investigated. In the PAC/UF system HA were removed in about 90%, whereas the complete removal of phenol was achieved for PAC dosage equal to 100 mg l(-1).