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Water utilities are increasingly considering indirect and direct potable reuse of municipal wastewater effluents. Disinfection byproducts (DBPs), particularly N -nitrosamines, are key contaminants of potential health concern for potable reuse. This study quantified the concentrations of N -nitrosamines and a suite of regulated and unregulated halogenated DBPs across five U.S. potable reuse Full Advanced Treatment trains incorporating microfiltration, reverse osmosis, and UV-based advanced oxidation. Low μg/L concentrations of trihalomethanes, haloacetic acids, dichloroacetonitrile, and dichloroacetamide were detected in the secondary or tertiary wastewater effluents serving as influents to potable reuse treatment trains, while the concentrations of N -nitrosamines were more variable (e.g., <2–320 ng/L for N -nitrosodimethylamine). Ozonation promoted the formation of N -nitrosamines, haloacetaldehydes, and haloacetamides, but biological activated carbon effectively reduced concentrations of these DBPs. Application of chloramines upstream of microfiltration for biofouling control increased DBP concentrations to their highest levels observed along the treatment trains. Reverse osmosis rejected DBPs to varying degrees, ranging from low for some (e.g., N -nitrosamines, trihalomethanes, and haloacetonitriles) to high for other DBPs. UV-based advanced oxidation eliminated N -nitrosamines, but only partially removed halogenated DBPs. Chloramination of the treatment train product waters under simulated distribution system conditions formed additional DBPs, with concentrations often equaling or exceeding those in the treatment train influents. Overall, the concentration profiles of DBPs were fairly consistent within individual treatment trains for sampling campaigns separated by months and across different treatment trains for the same sampling time window. Weighting DBP concentrations by their toxic potencies highlighted the potential significance of haloacetonitriles, which were not effectively removed by reverse osmosis and advanced oxidation, to the DBP-associated toxicity in potable reuse waters. [ABSTRACT FROM AUTHOR]

The United States Army is constructing a new water-treatment facility for Fort Irwin/National Training Center in the Mojave Desert region of southern California to address existing regulatory requirements and to account for anticipated expansion at the installation. The proposed treatment, electrodialysis reversal (EDR), is anticipated to recover 92% of the influent water. The ultimate goal was to achieve 99% recovery, which required additional recovery of the EDR concentrate. This paper describes laboratory testing of conventional watertreatment methods to achieve water recovery beyond standard practice. The effectiveness of lime softening followed by secondary reverse osmosis (RO) was evaluated to treat the concentrate stream and recover additional water to approach 98%. Partial lime softening at dosages of 500 - 2,000 mg/L of hydrated lime was capable of removing hardness from simulated EDR concentrate. Adding magnesium chloride to the lime softening step increased silica removal, bringing SiO2 concentrations in the simulated EDR concentrate from 110 to 6.8 mg/L at room temperature. The resulting treated water was suitable for effective reverse osmosis with a standard seawater polyamide membrane. Rejection for all of the dissolved constituents was well above 90% with the exception of arsenic, which was reduced from 50 μg/L to levels on the order of 20 μg/L. To achieve 99% recovery, mechanical vapor recompression is being considered to further recover the concentrate from the RO unit, although this unit process was not evaluated in the research reported in this paper. [ABSTRACT FROM AUTHOR]

The article discusses the use of direct potable reuse (DPR) in the U.S. It mentions the impact of the rapid increase of population and climate change in sustaining the supply of water in the country. Also emphasized are the process of the water reuse, the benefits of water reuse and the combination of water treatment technologies and processes including reverse osmosis and microfiltration.

A vision for the future was realized when the city of Scottsdale, Ariz., began operating the Scottsdale Water Campus in 1999 to augment the city's water supply and reclaim water. The facility remains at the forefront of water reuse. [ABSTRACT FROM AUTHOR]

A diffusion-control solute mass transfer model was developed to describe permeate water quality over time of operation. The changing mass transfer characteristics of four low-pressure reverse osmosis membranes were correlated to feed stream water quality in a 2,000-h pilot study. Solute mass transfer coefficients (MTCs) were correlated to initial solute MTCs, solute charge, feedwater temperature, monochloramine loading, and organic loading (ultraviolet light at 254 nm). Independent data were used to validate the model. The model can be used to predict permeate water quality and sensitivity of permeate water quality to variations in temperature and organic and monochloramine mass loading. [ABSTRACT FROM AUTHOR]

In order to meet the growing needs of its consumers, the Metropolitan Water District of Southern California is looking for ways to desalt water from the relatively hard Colorado River. This study evaluated conventional treatment as the pretreatment step for reverse osmosis (RO) desalting. Other pretreatment options studied include microfiltration (MF) and conventional treatment with ozone and biologically active filters. Each of three pretreatment scenarios produced effluent waters generally considered appropriate for use with RO [median turbidity of less than 0.1 Nephelometric turbidity unit (NTU) and median silt density index of less than 3]. Both microfiltered and ozonated/ biofiltered waters gave steady RO performance over 3 months of testing. However, conventional treatment left the RO system vulnerable to organic and biological fouling. Despite maintaining a 2-2.5 mg/L chloramine residual, pretreatment using conventional treatment required more frequent cleanings than either MF or ozonation/biofiltration (O3/BF). The good performance for biofiltered water may have resulted from the stabilization of the natural organic matter through the O3/BF process. Microfiltration, with its superior particle and bacteriological removal characteristics, provided the best RO pretreatment technology. [Copyright &y& Elsevier]

Studies the water quality management practices of a sample of households. Analysis of consumer concerns and satisfaction data; Implementation of reverse osmosis treatment systems; Adequacy of municipal water quality.

In the USA, STW Resources Holding Corp has announced that its wholly owned subsidiary STW Water has been selected to carry out the custom design, engineering and construction of a reverse osmosis (RO) concentrator for Horizon Regional Municipal Utility District in Horizon City, Texas. [ABSTRACT FROM AUTHOR]

Biwater Inc, which focuses on providing clean water and treating wastewater, has been awarded a contract to design, supply and supervise the installation and commissioning of both ultrafiltration (UF) and reverse osmosis (RO) systems for the Groundwater Reliability Improvement Program (GRIP) advanced water treatment facility that is being constructed in Pico Rivera, Southern California, USA. [ABSTRACT FROM AUTHOR]

Wescorp Energy Inc, a US company that develops water purification technology for the oil and gas production industry and for marine remediation projects, has coupled its H2Omaxx oil-water separation technology with reverse osmosis (RO). [Copyright &y& Elsevier]

H2O Innovation Inc has secured a C$10 million contract to design, build and supply major equipment and services for a seawater reverse osmosis (SWRO) system in the United States. [ABSTRACT FROM AUTHOR]

In the USA, EMCOR Group Inc's subsidiary Poole & Kent Co has been awarded a contract to install a reverse osmosis (RO) water treatment plant at a location in Clearwater, Florida. [Copyright &y& Elsevier]

US-based 3M Purification Inc has introduced the 3M Pro Reverse Osmosis Drinking Water Filtration System. It includes a high-pressure booster pump to increase the production of clean, palatable drinking water. [Copyright &y& Elsevier]

US-based Dow Water & Process Solutions (DW & PS), a business unit of Dow Chemical Co, has signed on its sixth trademark licensee as a part of the newly launched Filmtec reverse osmosis (RO) ingredient branding programme. [Copyright &y& Elsevier]

Many towns, cities and counties across the USA are facing water-quality challenges. Both ultrafiltration and reverse osmosis, based on membrane technology developed by Dow Water & Process Solutions, are helping communities produce clean drinking-water under tough conditions as these brief case studies show. [Copyright &y& Elsevier]

US company Pentair Inc has released details of its electronic water purification system for residential applications. [ABSTRACT FROM AUTHOR]

In the USA, eWaterOnline, a division of US company CAI Technologies Inc (CAI), is offering filtration and reverse osmosis drinking-water systems, ultraviolet sterilisation units, water softeners and a wide range of other products that can be easily installed by home owners to improve the quality of the water that is consumed daily. [Copyright &y& Elsevier]

US-based Siemens Water Technologies has introduced the Protegra CS water system. Combining reverse osmosis (RO) and continuous electrodeionisation (CEDI) technologies, it produces consistent ASTM Type II grade pure water from a soft water source. [Copyright &y& Elsevier]

A US company has successfully piloted a system, based on forward osmosis, that recycles wastewater generated by textile and carpet mills which use dyeing processes. This brief feature has the details of the system and highlights other potential applications for the technology, for example, generating and storing energy. [Copyright &y& Elsevier]

Presents information on the high density polyethylene (HDPE) pipe used in the El Paso County Water Authority Reverse Osmosis Treatment Project in Texas. Description of the HDPE pipes; Required solidity rate by the Environmental Protection Agency in drinking water; Aim of a reverse osmosis system.