A screening level fate model of organic contaminants from advanced water treatment in a potable water supply reservoir

Augmentation of potable water sources by planned indirect potable reuse of wastewater is being widely considered to address growing water shortages. Environmental buffers such as lakes and dams may act as one of a series of barriers to potable water contamination stemming from micropollutants in wastewater. In South-East Queensland, Australia, current government policy is to begin indirect potable reuse of water from reverse osmosis equipped advanced water treatment plants (AWTPs) when the combined capacity of its major storages is at 40% capacity. A total of 15 organic contaminants including NDMA and bisphenol A have been publically reported as detected in recycled water from one of South-East Queensland’s AWTPs, while another 98 chemicals were analysed for, but found to be below their detection limit. To assess the natural attenuation in Lake Wivenhoe, a Level III fugacity based evaluative fate model was constructed using the maximum concentrations of these contaminants detected as input data. A parallel aquivalence based model was constructed for those contaminants, such as dichloroacetic acid, dalapon and triclopyr, which are ionised in the environment of Lake Wivenhoe. A total of 247 organic chemicals of interest, including disinfection by-products, pesticides, pharmaceuticals and personal care products, xenoestrogens and industrial chemicals, were evaluated with the model to assess their potential for natural attenuation. Out of the 15 detected chemicals, trihalomethanes are expected to volatilise with concentrations in the outflow from the dam approximately 400 times lower than influent from the AWTPs. Transformation processes in water are likely to be more significant for NDMA and pharmaceuticals such as salicylic acid and paracetamol as well as for caffeine and the herbicides dalapon and triclopyr. For hydrophobic contaminants such as cholesterol and phenolic xenoestrogens such as 4-nonylphenol, 4-t-octylphenol and bisphenol A, equilibrium between water and sediments will not be attained and hence fate processes such as removal in outflow are predicted to become relatively important.     

Successful wastewater reuse scheme and sustainable development: a case study in Adelaide

Freshwater availability to meet the growing needs of humankind has raised serious concerns in the recent past. Two immediate responses to counter this challenge are efficient allocation of the scarce resources, and development and use of alternative sources of water. While ‘water markets’ are seen as a means to achieve efficient allocation of the scare resources, treated wastewater and low‐quality water are now considered as potential sources of water to supplement the freshwater supplies. However, the latter option, that is use of reclaimed water as an alternative, imposes concerns regarding its suitability to sustain development. This is because of various issues related to wastewater usage and application. At the same time, it is also true that a successful and well‐planned reuse scheme can help achieve sustainability as evidenced in some isolated cases around the world. In line with this, the current paper adopts a case‐study approach to demonstrate how a successful reuse scheme in Adelaide, South Australia, has contributed to the sustainable development of the region. The paper looks into the socio‐economic and environmental dimensions of sustainability and arrives at a conclusion that properly planned and managed reuse schemes backed with effective regulatory and policy measures can lead to sustainable development.     

浅析中水回用在天津地区水资源利用中的作用

结合国内外污水处理市场发展趋势,分析了天津地区开展中水回用工程建设的可行性,简要介绍了中水的概念及中水回用工艺等内容,针对天津地区中水发展现状进行了探讨,指出了存在的问题,以期提高人们的中水回用意识,促进中水事业的发展。     

大港油田再生水厂工艺介绍

介绍了大港油田再生水厂的处理工艺,包括污水处理工程、深度处理回用工程、污泥处理三部分。分别论述了这三个阶段选用的工艺方法,并结合环境和市场分析论证了该工程处理工艺的可行性。再生水厂出水回用作热电厂、聚丙烯厂、煅烧焦厂工艺用水,具有较好的经济效益、环境效益和社会效益。     

Predictive Chlorine Dosing: A New Paradigm

Disinfection by chlorine is common practice in potable water treatment. The most frequently used dose control method is to inject an overdose of chlorine at the inlet to the contact tank and adjust to the desired residual chlorine level in the effluent stream. However, this method of control may not be optimal. The advent of reliable predictions of retention time distributions and the widespread use of programmable logic controllers, coupled with a greater understanding of chlorine disinfection kinetics, offers the potential for more efficient chlorine dosing algorithms. This paper describes one possible algorithm, based on theoretical models, for predictive chlorine dosing.     

Comparing microfiltration-reverse osmosis and soil-aquifer treatment for indirect potable reuse of water

Microfiltration (MF) followed by reverse osmosis (RO) and soil-aquifer treatment (SAT) are the two principal technologies considered for indirect potable reuse of wastewater. This study, conducted at the Northwest Water Reclamation Plant, Mesa (Arizona), evaluated MF/RO and SAT (>6 months residence time) treated tertiary effluent with respect to organics removal. Effluent organic matter was characterized as total organic carbon (TOC), by UV absorbance (UVA), solid-state carbon-13 nuclear magnetic resonance spectroscopy, and size exclusion chromatography. Several trace organic micropollutants, including EDTA, NTA, and alkylphenolethoxylate residues, were analyzed by GC/MS. The study revealed that final TOC concentrations of MF/RO and SAT are 0.3 and 1.0 mgl(-1), respectively. Based on the characterization techniques used, the character of bulk organics present in final SAT water resembles the character of natural organic matter present in drinking water. Depending on the molecular weight cut-off, RO membranes can efficiently reject high molecular weight organic matter (characterized as humic and fulvic acids). However, approximately 40-50 percent of the remaining TOC in permeates consists of low molecular weight acids and neutrals representing a molecular weight range of approximately 500Da and less. In the SAT treated effluent, EDTA and APECs were removed to approximately 4.3 and 0.54 microg/l, respectively, but were below the detection limit in the MF/RO treated effluent.     

城市污水回用深度处理方法及其研究进展

介绍了城市污水回用深度处理的概念,总结了几种常见的城市污水回用深度处理方法,对它们的原理和特点进行了简单概述,并阐述了近年来这些深度处理方法的研究进展,从而使城市污水作为新的资源得以循环利用,提高了城市资源的利用率。     

家用中水设备的试验研究

我国是一个严重缺水的国家 ,再生水资源利用是解决我国缺水问题的一个有效途径 .通过对某住宅小区居民生活用水状况调查以及对家庭杂排水的一体化处理过程的实验研究 ,提出了利用无泵升压技术发展个体化、小型化的家庭废水回用设备 ,是居民家庭节水的有效措施 .     

Activated charcoal and microflora in water treatment

Significant sanitation was achieved by using 0.5% activated charcoal in influent and effluent of a wastewater treatment plant. The drastic reduction in the microorganisms was confirmed for twelve tester strains, including gram-positives, gram-negatives, Candida albicans, Vahlkampfia avara, Leptospira biflexa and Trichomonas foetus. The removal of microflora correlates positively with the quality of the activated charcoal used. Once adsorbed, the bacteria could not be eluted by salt, alkalinization or citric acid. Diatomaceous earth also eliminated some of the microflora, but white clay (Bolus alba) and zinc dust are inefficient. The activated carbon may be reused several times after regeneration by heat (2 h at 160°C), but eventually a slight decrease in adsorbing capacity occurs.     

Nutrient recovery and crop yield enhancement in irrigation with reclaimed wastewater: a case study

The paper reports results of treated wastewater reuse field experiments carried out in Apulia (Southern Italy). Fennel and lettuce were irrigated with four different water sources: three reclaimed wastewater streams, obtained by applying different treatment schemes to the same municipal wastewater, and a conventional source (well water). Differences between the three effluents were significant in terms of suspended solids and faecal indicators. Both lettuce and fennel yields were enhanced by the high content of nutrients in the effluent of one of the treatment plants, which had been operated for partial nitrogen removal. In particular, fennel productivity was enhanced by replacing chemical fertirrigation with the supply of nutrients contained in the irrigation water.     

A synopsis of membrane technologies in UK municipal potable water treatment: history, status and prospects

The current status of membrane filtration for potable water and wastewater applications is assessed with reference to recent history and key legislative drivers. The current installed capacity for potable water membrane treatment is around 1100 ML/day provided by over 100 plants, with the majority being conventional pumped systems using hollow fibre ultrafiltration (UF) or microfiltration (MF) membranes. An examination of the distribution of membrane plants reveals that capacity is provided predominantly by two commercial UF/MF membrane suppliers, but that a large number of smaller nanofiltration plants have been installed in one UK region. Future prospects for desalination are considered.     

台北市国际金融大厦中水处理系统

台北市国际金融大厦将其产生的杂排水（800m^3/d）经过二级处理及砂滤、活性炭吸附、软化等三级处理后与经物化、砂滤处理的雨水（100 m^3/d）汇集,进入中水处理系统.工程实践表明,系统运行稳定,出水水质良好,可用于机电设备和空调冷却、消防、冲厕、绿化等.     

Anaerobic biodegradability and treatment of grey water in upflow anaerobic sludge blanket (UASB) reactor

Feasibility of grey water treatment in an upflow anaerobic sludge blanket (UASB) reactor operated at different hydraulic retention time (HRT) of 16, 10 and 6h and controlled temperature of 30 degrees C was investigated. Moreover, the maximum anaerobic biodegradability without inoculum addition and maximum removal of chemical oxygen demand (COD) fractions in grey water were determined in batch experiments. High values of maximum anaerobic biodegradability (76%) and maximum COD removal in the UASB reactor (84%) were achieved. The results showed that the colloidal COD had the highest maximum anaerobic biodegradability (86%) and the suspended and dissolved COD had similar maximum anaerobic biodegradability of 70%. Furthermore, the results of the UASB reactor demonstrated that a total COD removal of 52-64% was obtained at HRT between 6 and 16 h. The UASB reactor removed 22-30% and 15-21% of total nitrogen and total phosphorous in the grey water, respectively, mainly due to the removal of particulate nutrients. The characteristics of the sludge in the UASB reactor confirmed that the reactor had a stable performance. The minimum sludge residence time and the maximum specific methanogenic activity of the sludge ranged between 27 and 93 days and 0.18 and 0.28 kg COD/(kg VS d).     

试论太原市实施污水回用的必要性

分析了太原市水资源短缺的状况及节约水资源的基本途径，提出了缓解太原市水资源紧张局面，节约新鲜水资源的一种方法——污水回用，阐述了污水资源化利用的可行性。     

含油废水再生利用处理工艺研究

对不同含油废水的常用处理方法作了简单介绍,研究了中国石化山东炼油厂对含油污水的处理工艺,对反渗透后产生的浓水回用作了探讨,并提出了今后对含油废水处理技术的一些建议与展望.     

Urban net-zero water treatment and mineralization: Experiments,modeling and design

Water and wastewater treatment and conveyance account for approximately 4% of US electric consumption, with 80% used for conveyance. Net zero water (NZW) buildings would alleviate demands for a portion of this energy, for water, and for the treatment of drinking water for pesticides and toxic chemical releases in source water. However, domestic wastewater contains nitrogen loads much greater than urban/suburban ecosystems can typically absorb. The purpose of this work was to identify a first design of a denitrifying urban NZW treatment process, operating at ambient temperature and pressure and circum-neutral pH, and providing mineralization of pharmaceuticals (not easily regulated in terms of environmental half-life), based on laboratory tests and mass balance and kinetic modeling. The proposed treatment process is comprised of membrane bioreactor, iron-mediated aeration (IMA, reported previously), vacuum ultrafiltration, and peroxone advanced oxidation, with minor rainwater make-up and H₂O₂ disinfection residual. Similar to biological systems, minerals accumulate subject to precipitative removal by IMA, salt-free treatment, and minor dilution. Based on laboratory and modeling results, the system can produce potable water with moderate mineral content from commingled domestic wastewater and 10–20% rainwater make-up, under ambient conditions at individual buildings, while denitrifying and reducing chemical oxygen demand to below detection (<3 mg/L). While economics appear competitive, further development and study of steady-state concentrations and sludge management options are needed.     

养殖废水处理与高效再利用系统的设计

针对简阳市五友玉成二元种猪场养殖废水排放所造成的严重污染问题,借鉴目前国内外先进的污水处理理念与技术,将快滤池、人工湿地及慢滤池净化污水与农业灌溉紧密结合,建立了经济适用的养殖废水处理与高效利用系统.该系统对废水中的COD、TP和NH4--N的去除率分别达70%、82%和62%,但对NO3--N和NO2--N的去除还有待改进.     

Effect of Khirbet As-Samra treated effluent on the quality of irrigation water in the Central Jordan Valley

Khirbet As-Samra (KA) treated wastewater is being used in irrigation in the Central Jordan Valley. The treated water is collected in King Talal Dam (KTD) and then mixed with King Abdullah Canal (KAC) water, which is diverted from the Yarmouk River for further use in agriculture. The treated water has adversely affected the water quality of Yarmouk River. Comparison of the results of water quality tests with guidelines for water to be used for irrigation, salt tolerance of agricultural crops and the influence of water quality on the potential clogging of drip irrigation systems reveals that treated effluent from KA can be used for irrigation with restrictions. Moreover, concentrations of all trace elements were found to be low and within guidelines for irrigation water. Clogging of drip emitters is expected due to high calcium and magnesium contents, besides the high bacterial counts and nutrients that promote algal growth.     

洗衣废水与屋面雨水合排的危害及解决方法

阐述了洗衣废水与屋面雨水合用排水管对环境产生的危害，提出了解决问题的办法，并对废水回用技术进行了投资估算和费用效益分析，指出废水回用是环境保护的方法之一。