Computational fluid dynamics applied to water and wastewater treatment facility modeling

The major issues in water and wastewater industry are to meet quality requirements, to guarantee treatment process efficiency, to contain investment and operating costs. This implies the use of powerful predictive modeling and simulation tools which are able to account for the multiple interaction between all the water quality and process design parameters. Computational Fluid Dynamics modeling tools have already been widely used in other industries but their application in water industry is quite recent. This paper presents different applications of CFD modeling to the study of the hydro-dynamic and mass transfer performance of single- or two-phase flow reactors used in water and wastewater treatment. Numerical simulations, together with experimental measurements, have been performed on laboratory and full-scale plants in order to gain a better under-standing of the physical phenomena (mixing, interfacial transfer) occurring in these systems. Numerical simulations are systematically validated by experiments. The paper shows how CFD can be helpful in order to improve the design of existing water treatment plants and the process efficiency. In this scope, CFD enables designs more reliable and cost effective water treatment processes which remain basic environmental policy issues.     

数值模拟在污水生物处理领域应用进展

随着计算机技术的发展,数值模拟在污水生物处理工艺设计、水处理设备结构优化等领域中已得到广泛应用。介绍了数值模拟技术常用的计算方法,对活性污泥法、MBR、厌氧消化等污水生物处理领域中的数值模拟研究进展进行了总结评述,讨论了模拟仿真过程中模型选择、简化假设、预测控制等关键问题。目前数值模拟在污水生物处理领域得出的多是导向性结论,将模拟与实验结合可以提升研究效率,更好地解决工程问题。     

工业废水污染治理途径与技术研究发展需求

根据工业废水的特点,构建科学合理的废水处理模式,不断完善和发展废水处理技术及水质安全评价与管理技术是水环境污染防治领域的重要课题. 在分析工业废水特点和阐述废水污染治理基本策略与途径的基础上,重点介绍了工业废水处理特性评价、工艺优选方法、水质安全管理等方面的研究进展,并探讨了废水污染治理思路和技术的发展方向. 指出工业废水污染治理应实现以下5个方面的转变和发展,即处理模式从不同种类废水混合收集集中处理向分类收集分别处理优先转变;研究开发从重视废水处理单一技术研发向同时重视废水处理技术集成与处理工艺优化方法研究转变;水质有机污染评价从重视综合浓度指标向同时关注和重视“有机物特征指标”转变;废水排放控制指标从重视常规指标向同时关注和重视水质安全和综合生物毒性指标转变;工艺设计理念从“处理工艺”向“生产工艺”转变.      

污水处理厂N2O的释放特征和减排途径研究

温室气体N2O含量的增加对气候变化产生显著影响,针对污水处理行业N2O减排控制的发展趋势与需求,以典型污水生物处理工艺为对象,对N2O产生机理、释放特征和核算、影响因素进行了综述和分析.研究表明,污水处理厂N2O的释放主要来自生物脱氮过程的硝化阶段和反硝化阶段,不同污水处理厂的N2O释放因子和释放特征不同.DO、温度和C/N是影响N2O释放的主要因素,最后从污水处理厂工艺运行和水质调控角度提出了具有可操作性的N2O减排途径与方法.     

集中式污水厂重金属排放限值及其控制进展研究

介绍了中国集中式污水厂污水处理现状,主要包括污水厂进出水监测指标和进出水水质指标设计不足,重金属处理效果不明显;同时对国外污水处理现状以及重金属排放限值进行比较,探讨了中国污水处理厂污水中重金属排放限值及控制的问题,污水中重金属处理工艺未设计,进出水水质指标未将重金属指标纳入设计中,重金属排放限值远高于发达国家限值.结合现状分析,提出加强污水处理厂重金属源头控制与排放限值监管的相关建议,以确保排放水体的环境安全.     

小型城市污水厂设计中的问题及探讨

分析了小型城市污水厂的特点和存在的问题。处理工艺的优化选择是解决问题的关键。必须根据当地的水质、水量特点、受纳水体的水质标准、经济状况选择工艺类型     

半导体行业废水的反渗透膜污堵机制与控制策略

半导体行业是我国大力发展的高精尖产业,废水产生量大、再生处理难度高.半导体行业废水再生处理过程中,反渗透(reverse osmosis, RO)是重要的污染物去除单元,但面临的膜污堵问题严重影响了其效率与经济性.本文梳理了半导体行业废水的种类与典型污染物,总结了半导体行业废水导致反渗透膜污堵的主要机制及控制手段,提出了针对半导体行业废水特点的膜污堵控制策略.半导体生产的不同工序会产生多种废水,包括含氟废水、含磷废水、含氨废水、重金属废水、有机废水与酸碱废水等.废水中污染物种类多且可生化性普遍较差.通常,不同种类废水分类经分质收集后,进行相应的预处理,之后部分合流处理并进入RO系统.半导体行业废水中的金属离子或氟离子易在反渗透膜面形成无机结垢,表面活性剂易形成有机污堵.反渗透膜污堵可通过预处理、膜清洗与运行条件调控等手段进行控制,如超滤、EDTA清洗剂与pH调节等,但大部分现有手段对半导体行业废水造成的污堵控制能力有限.建议未来开发针对关键污染物的预处理技术与定制化的膜清洗方案;并结合半导体生产工序,提出针对污染物关键相互作用关系的废水收集与再生处理整体策略.     

Water and wastewater eco-efficiency indicators for the sugar cane industry

The consumption of large volumes of water and the generation of organic compounds as liquid effluents are major environmental problems in sugar cane processing industry. The volume of freshwater required by this industry can be significantly reduced by recovering the intrinsic water present in sugar cane. This amount of freshwater will depend on the process technology. Three new indices for sugar cane plants are introduced in this work: WIN, which indicates the efficiency of water use, and EIN1 and EIN2, which quantify Chemical Oxygen Demand of wastewater. Selected case studies illustrate the advantages of employing these indices as guides for the selection among process design alternatives that account for environmental performance.     

基于未确知测度识别模型在污水处理厂运行效率评价中的应用

污水处理厂运行效率定量评价是当前污水处理行业管理与研究需要解决的问题,运行效率涉及到污水处理水量、水质和污染物的去除率、能耗和药荆消耗等方面诸多项指标。是多指标综合评价问题。文章借助未确知测度识别数学理论．构造了污水处理厂运行效率定量评价模型。并应用于某污水处理厂的运行效率评价,取得了较满意的效果。     

BIOLAK工艺在污水处理中的应用

辽宁诸城市污水处理厂采用德国BIOLAK工艺,以某县城污水处理厂工程设计为实例,详细介绍了该工艺流程、主要设计参数以及工艺特点等.说明该工艺占地小、处理效率高、出水水质好等特点,适用于城市污水的处理.     

城市污水处理工艺的对比研究

介绍了包头市现有五座城市污水处理厂概况,分析了处理工艺低温的适应性。通过分析其中三座采用不同工艺相似水质污水处理厂的进、出水水质,研究不同处理工艺的处理效果。通过设定相同处理规模,分析三种不同工艺相同规模污水处理厂的经济性。最终得出目前包头市处理效果最佳、经济性最优的城市污水处理工艺,为包头市城市污水处理厂提标改造提供参考。     

城镇污水处理厂进水中地下水、河水及雨水混入比例研究

进水污染物浓度低及比例失调是目前许多城镇污水处理厂面临的问题,然而鲜有关于渗漏来源及定量分析的相关文献报道。为定量分析河水、地下水、雨水、管道中污染物降解等因素对污水浓度降低的影响,通过水量平衡三角法,并结合典型位点的24 h采样测试分析及S-P降解模型,对目标城镇污水处理厂进水组成进行分析。历史水量数据结合降雨情况分析表明,该污水处理厂进水中实际原生污水量仅为60.0%左右,其余40.0%左右为地下水及河水渗入量或雨水混入量。在连续晴天无降雨的情况下,小区自建管网和市政排水管网是主要的渗漏源,其对于进水有机物浓度降低的贡献分别为20.2%和26.4%。此外,在25 mm降雨量情况下,小区自建管网是主要的渗漏源,对于进水浓度降低的贡献达到39.5%。因此在污水处理提质增效工作中,小区自建管网的完善程度应引起关注。     

我国利用水生植物监测和净化污水的研究进展

本文综述了我国利用水生植物监测和净化重金属废水、化工废水、生活污水、放射性核素废水以及抑制富营养化水体中藻类研究进展。并讨论了各种生态因子对水生植物净化效率的影响。为建立低投资、高效率、易管理的植物净化处理设施提供参考。     

长沙市敢胜垸污水处理厂深度处理工艺的筛选研究

在二级生物处理工艺确定后,深度处理工艺的选择是保证整个工程出水水质的关键。过滤是污水深度处理工艺中最重要的工序,用以去除原水经沉淀后的残留絮体和杂质,具体依据出水效果、处理效率、投资成本和占地等各方面,确定采用深床过滤工艺。从整体优化的角度出发,结合设计规模,进水水质特征和出水水质要求以及当地的实际条件和要求,选择切实可行且经济合理的深度处理工艺方案,是实现整个长沙市敢胜垸污水处理厂最佳工艺方案的保障。     

Prediction of effluent concentration in a wastewater treatment plant using machine learning models

Of growing amount of food waste, the integrated food waste and waste water treatment was regarded as one of the efficient modeling method. However, the load of food waste to the conventional waste treatment process might lead to the high concentration of total nitrogen (T-N) impact on the effluent water quality. The objective of this study is to establish two machine learning models—artificial neural networks (ANNs) and support vector machines (SVMs), in order to predict 1-day interval T-N concentration of effluent from a wastewater treatment plant in Ulsan, Korea. Daily water quality data and meteorological data were used and the performance of both models was evaluated in terms of the coefficient of determination (R²), Nash–Sutcliff efficiency (NSE), relative efficiency criteria (d_rel). Additionally, Latin-Hypercube one-factor-at-a-time (LH-OAT) and a pattern search algorithm were applied to sensitivity analysis and model parameter optimization, respectively. Results showed that both models could be effectively applied to the 1-day interval prediction of T-N concentration of effluent. SVM model showed a higher prediction accuracy in the training stage and similar result in the validation stage. However, the sensitivity analysis demonstrated that the ANN model was a superior model for 1-day interval T-N concentration prediction in terms of the cause-and-effect relationship between T-N concentration and modeling input values to integrated food waste and waste water treatment. This study suggested the efficient and robust nonlinear time-series modeling method for an early prediction of the water quality of integrated food waste and waste water treatment process.     

印染废水吸附处理研究现状

随着染料纺织工业迅速发展,产生的印染废水成了水系环境的主要污染源之一,而染料品种的日益增加,及产品结构和印染工艺的不断改变,使得印染废水的水质也发生了变化,处理难度也随之加大。本文主要介绍不同的吸附处理法的优缺点及它们对不同污染因素的吸附效率。通过对几类吸附方法的比较,发现新兴的秸秆纤维素类生物吸附剂,既可以有效的解决农业固体废弃物的处理问题,又能低成本高效率的处理印染废水,对我国建立发展可持续发展,环境友好型社会具有重要的意义。     

Prediction of effluent concentration in a wastewater treatment plant using machine learning models

Of growing amount of food waste, the integrated food waste and waste water treatment was regarded as one of the efficient modeling method. However, the load of food waste to the conventional waste treatment process might lead to the high concentration of total nitrogen(T-N) impact on the effluent water quality. The objective of this study is to establish two machine learning models—artificial neural networks(ANNs) and support vector machines(SVMs), in order to predict 1-day interval T-N concentration of effluent from a wastewater treatment plant in Ulsan, Korea. Daily water quality data and meteorological data were used and the performance of both models was evaluated in terms of the coefficient of determination(R~2), Nash–Sutcliff efficiency(NSE), relative efficiency criteria(d rel). Additionally, Latin-Hypercube one-factor-at-a-time(LH-OAT) and a pattern search algorithm were applied to sensitivity analysis and model parameter optimization, respectively. Results showed that both models could be effectively applied to the 1-day interval prediction of T-N concentration of effluent. SVM model showed a higher prediction accuracy in the training stage and similar result in the validation stage.However, the sensitivity analysis demonstrated that the ANN model was a superior model for 1-day interval T-N concentration prediction in terms of the cause-and-effect relationship between T-N concentration and modeling input values to integrated food waste and waste water treatment. This study suggested the efficient and robust nonlinear time-series modeling method for an early prediction of the water quality of integrated food waste and waste water treatment process.     

广西壮族自治区污水处理厂运行状况及特征分析

基于广西壮族自治区126座污水处理厂2015年运行状况的调查数据,分析广西污水处理厂的工艺特点、污泥处置、出水水质达标情况、运行负荷率和运行费用,评估污水处理厂运行的效率和效果,分析存在的问题,并就污水处理厂的运行和管理提出建议。     

污水处理工艺数据分析技术的现状与趋势

数据科学的飞速发展为污水处理厂工艺数据分析提供了有力的技术工具。在污水处理工艺运行中应用数据分析技术,需要克服数据、算法和算力上的困难。介绍了污水处理工艺数据分析技术的发展现状,总结了其在数据质量和数学模型方面的技术难点,分析了污水处理工艺数据分析技术的4种典型应用场景,介绍了12个国内外数据分析集成应用的案例,评估了工艺数据分析技术的成熟度和行业应用的就绪度,讨论了技术的发展趋势。研究结果有助于污水处理系统运管人员掌握工艺数据分析技术进展和运用数据分析技术处理业务的需求。     

重介质加载磁分离矿井水净化技术在亭南煤矿的应用

为了提高矿井水出水水质指标,有效降低废水排放对环境的影响,实现环境保护和水资源重复利用,亭南煤矿实施了矿井水处理站扩容改造工程。该工程采用重介质加载磁分离矿井水净化技术,使处理后的矿井水全部达到工业生产用水水质要求和排放标准,详细介绍了该技术的原理和特点,并对工程实施后的效果进行了经济效益分析。应用结果表明,该技术对煤炭行业高悬浮物矿井水的净化处理具有一定的优势,具有占地面积小、处理效率高等特点。