Water Purification Facilities Research Articles

Screening of powdered activated carbons to remove 2-methylisoborneol for drinking water

A 95% confidence interval was estimated from 2-methylisoborneol (2-MIB) numbers, as an index of adsorption capacity described in this article, for 31 different powdered activated carbons (PACs) used for drinking water purification. The seven PACs selected in this study were chosen as five of them were within the 95% confidence interval and the other two PACs were not. The PACs were assessed based on previous studies, which represented the relationships between 2-MIB adsorption capacity and surface area, pore distribution, bulk oxygen content and surface oxygen functional groups. From the results, we assumed the 2-MIB adsorption mechanism and studied relationships between 2-MIB number and ash content of PAC or pH value of PAC slurry. It was shown that the 2-MIB number correlated with the ash content and the pH value. Easily measurable ash content and pH values would help a water supplier briefly screen PACs for removing 2-MIB at a water purification facility.

Adsorption Characteristics of As(III) and As(V) on Alum Sludge from Water Purification Facilities

The contamination of water by arsenic (As) is a serious environmental problem, and many cost effective adsorbents have been developed to solve this problem. This study examines the effectiveness of reusing alum sludge from water purification facilities as adsorbents of As in aqueous systems. Adsorption kinetics and adsorption isotherm by temperature were the methods investigated. Kinetics revealed that the adsorption of As(III) and As(V) has rate-limiting steps such as surface diffusion and pore diffusion. In the equilibrium study, Langmuir isotherm was well fitted to experimental data and the adsorption of As was found to be dependent on the solution's pH, temperature, and competitive ions such as phosphates. Using the column experiment, the feasibility of alum sludge for As adsorption was also tested. The results showed that alum sludge can be used as an effective adsorbent of As in water treatment systems.

Environmental sanitation and health facilities in schools of an urban city of south India

Background : Environmental sanitation and health facilities in schools are an important public health issue. Aims : To assess the school environment, sanitation and health related facilities and to compare the availability of these facilities between government, aided and private schools. Materials and Methods : This cross sectional study was done in 30 schools in Mangalore city of south India in February 2010. Results : Out of the 30 schools surveyed, four were government, 12 were aided and 14 were private schools. Overcrowding was seen in one third of schools. The recommended minus desks was lacking in 23(76.7%) and chairs with back rest was lacking in 11(36.7%) schools. More than a quarter of schools had no drinking water purification facility. Water storage units were not cleaned periodically in 6(20%) schools. Quarter of all government schools and half of all aided schools had no dining hall for serving mid-day meals. Toilets were not adequate in 10(33.3%) and it was not separated for boys and girls in 8(26.7%) schools. Four of the surveyed schools had no medical examination of students and in 13(43.3%) schools daily morning inspection by teachers was not done. Hardly few schools had staff trained to deal with medical emergencies and in counselling activities. None of the schools had an immunization register. Although the performance scores between the types of schools did not differ significantly, the combined performance of only private schools were found to be satisfactory. Conclusion : A good number of schools in this urban area were found to be falling short of several essential requirements regarding sanitation and health facilities which needs to be rectified.

Molecular characterization of effluent organic matter identified by ultrahigh resolution mass spectrometry

Effluent dissolved organic matter (EfOM) collected from the secondary-treated wastewater of the Orange County Sanitation District (OCSD) located in Fountain Valley, California, USA was compared to natural organic matter collected from the Suwannee River (SRNOM), Florida using ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Furthermore, the two different treatment processes at OCSD, activated sludge and trickling filter, were separately investigated. The blend of these two effluents was further evaluated after it had passed through the microfiltration process of the Advanced Water Purification Facility (AWPF) at Orange County Water District (OCWD). EfOM contained 872 different m/ z peaks that were unambiguously assigned to exact molecular formulae containing a single sulfur atom and carbon, hydrogen and oxygen atoms (CHOS formulae). In contrast, the SRNOM sample only contained 152 CHOS formulae. The trend in CHO molecular compositions was opposite with 2500 CHO formulae assigned for SRNOM but only about 1000 for EfOM. The CHOS-derived mass peaks with highest abundances in EfOM could be attributed to surfactants such as linear alkyl benzene sulfonates (LAS), their co-products dialkyl tetralin sulfonates (DATS) and their biodegraded metabolites such as sulfophenyl carboxylic acids (SPC). The differences between the treatments were found minor with greater differences between sampling dates than treatment methods used.

Development of a Highly Sensitive and Simultaneous Analytical Method for 20 Elements in Raw and Tap Waters Using DRC-ICP/MS and Removal Characteristics of These Elements in the Process of Water Treatment

A simultaneous multi-component analytical method for 20 types of elements in raw and tap-water samples (Cd, Se, Pb, As, Cr, B, Zn, Al, Fe, Cu, Mn, Sb, U, Ni, Ba, Bi, Ag and Mo, as listed in the "Water Works Law", and Li and Sr, which are not-listed but are frequently detected) was studied using DRC-ICP/MS. The investigation revealed 1) that the optimum cell-gas flow rates to control plasma-based interferences was 0.3 mL min−1 for As and 0.6 mL min−1 for the other elements (Cr, Mn, Fe, Ni, Cu, Zn and Se), and 2) that Be, Ga, In and Tl are the most appropriate elements for the internal standards, except in the cases of Co and Y, which are influenced by their concentration level in raw water. Under these analytical conditions, verification by spiked recovery tests exhibited that the recovery rate is 90 – 110%, and that the variation coefficient is below 10%. The levels of the determination limits for each element were ng L−1 – μg L−1, which demonstrates the possibility of measurements for low-concentration samples. From all of these results, this analytical method has been confirmed to be both highly sensitive and accurate. Furthermore, studies of the removal performance for 20 different elements from raw to tap water in an advanced water-purification facility showed that Mn, U, Fe, Bi, Ag and Al can be easily removed (removal ratio of over 80%). On the other hand, Se, Li, Sb, Ba, B, Mo and Sr can hardly be removed (removal ratio of below 20%).

The Oxnard advanced water purification facility: combining indirect potable reuse with reverse osmosis concentrate beneficial use to ensure a California community's water sustainability and provide coastal wetlands restoration

The City of Oxnard in California is implementing a strategic water resources program known as the Groundwater Recovery Enhancement and Treatment (GREAT) program, which includes an Advanced Water Purification Facility (AWPF) that will use a major portion of the secondary effluent from the City's existing Water Pollution Control Facility to produce high-quality treated water to be used for irrigation of edible food crops, landscape irrigation, injection into the groundwater basin to form a barrier to seawater intrusion, and other industrial uses. The AWPF, currently under design by CH2M HILL, will employ a multiple-barrier treatment train consisting of microfiltration, reverse osmosis, and ultravioletlightbased advanced oxidation processes to purify the secondary effluent to conform to California Department of Public Health Title 22 Recycled Water Criteria for groundwater recharge. The AWPF, which will have initial and build-out capacities of ca. 24,000 and ca 95,000 m(3)/day, respectively, was limited to a 1.8-hectare site, with 0.4 hectares dedicated to a Visitor's Center and administration building. Further, the depth below grade and height of the AWPF's structures were constrained because of the high groundwater table at the site, the high cost of excavation and dewatering, and local codes. To accommodate these various restrictions, an innovative design approach has been developed. This paper summarizes the design constraints and innovative solutions for the design of the AWPF.

Toilet to Tap: Making a Case for Indirect Potable Reuse

This article discusses negative public opinion about indirect potable water reuse, efforts at obtaining public approval by the Orange County Water District of Southern California, the water treatment process at Orange County's state‐of‐the‐art water reclamation facility referred to as the Advanced Water Purification Facility, and the obvious choice of using indirect potable water reuse to meet the earth's future water needs.

Deterioration of granular activated carbon collected from post-ozonation upflow fluidized bed contactor—influence of particle diameter

An examination was undertaken of the properties of granular activated carbon (GAC) collected from a post-ozonation upflow fluidized GAC contactor at a full-scale advanced water purification facility operated by the Hanshin Water Supply Authority (HWSA), Japan. Activated carbon (AC) was collected from the upper, middle, and lower layer of the contactor and fractionated by a series of sieves. The amount of manganese, iron and calcium accumulated on each fraction was estimated by hydrochloric acid extraction test. The amount of iodine adsorption (I N ) was also measured. The amounts of metal accumulated were 1.2–89 (mg Mn g−1), 1.4–4.3 (mg Fe g−1), and 6.6–32 (mg Ca g−1). The amount was affected not only by the layer from which the carbon was collected but also by the average particle diameter of each fraction. I N was in the range of 119–527 (mg g−1) and decreased from the lower through the middle to the upper layer. Judging from I N , the AC collected from the upper layer, the furthest downstream, was subject to particular deterioration. A number of potential factors affecting the deterioration of GAC were suggested.

Evaluation of source water quality for selection of drinking water purification system

When renewing water purification facilities, it is important to select a suitable purification system that can accommodate the quality of the respective source water. The Japan Water Research Center has been collecting a large amount of water quality data from drinking-water utilities across Japan, categorising and analysing these data, and evaluating the suitability of water purification processes. Multivariate analyses such as hierarchical cluster analysis and principal component analysis were performed to investigate the relationships between the quality of source water used for water supply and various factors that affect the purification process. Based on these results, water sources throughout Japan were clearly categorised into four groups, and suitable water purification systems were identified for the different water quality groups. The results can serve as an important reference for water utilities during future facility renewal projects.

한강에서의 강변여과수 개발을 위한 적지선정 및 개발가능량 산정(I)

선진국에서의 강변여과수 개발은 150년 정도의 역사를 가지고 있다. 한국에서도 지속적으로 증가하고 있는 용수수요에 안정적으로 대처하기 위한 원수 확보방안으로 강변여과수에 대한 조사가 1990년대부터 4대강 유역을 중심으로 시작되었으며, 현재 낙동강을 중심으로 강변여과를 활용한 상수도 공급이 이루어지고 있다. 본 논문은 서울의 원수수질 안정을 위한 방안으로 강변여과 도입의 타당성에 대한 연구이다. 개발 적지의 선정을 위해 여러 가지 속성들을 계층적으로 분류하고 각 속성의 중요도를 파악함으로써 최적 대안을 선정하는 계층분석과정기법(AHP)을 적용하였다. 한강 유역의 경우 개발후보지역을 대상으로 적지분석을 실시한 결과, 수질 및 기존시설연계성 등에서 유리한 광나루지구가 최적지로 선정되었다. Riverbank filtration for water supply has been employed for about 150 years in developed countries. In Korea, the feasibility of riverbank filtration has been investigated since 1990's for large river basins, to find a solution to stably meet the ever-increasing demand for water. Recently, some cites in the Nak-dong River Basin have been supplying the water through riverbank filtration. This research studies the feasibility of riverbank filtration in Seoul. Analytic Hierarchy Process (AHP), which selects the most optimal alternative by hierarchically classifying various attributes and then quantifying the importance of each attribute, was applied to candidate locations for the selection of riverbank filtration site. The Kwangnaru district, which has advantages in water quality and close connectivity to the existing water purification facility, was selected as the most optimal site.

Effectiveness of UV Advanced Oxidation for Destruction of Micro-Pollutants

UV light has become increasingly well-established as an effective primary disinfectant for Giardia and Cryptosporidium. Many utilities are now focusing attention on control of emerging contaminants, and looking at the effectiveness of UV advanced oxidation as part of a multiple-barrier treatment train for improving water quality. In research and a small number of full-scale applications, a UV advanced oxidation process (AOP) has been shown to be effective as part of a multiple-barrier water purification train. For the City of Aurora, Colorado, the Aurora Reservoir Water Purification Facility will include UV AOP as part of a multiple barrier approach to provide disinfection, nitrosamine destruction, and micro-pollutant removal. Bench-scale testing was performed to evaluate the effectiveness of UV AOP for the control of nitrosamines and other micro-pollutants. Compounds tested included N-nitrosodimethylamine (NDMA) and 8 other nitrosamines. The test results showed predictable and repeatable destruction of NDMA, and destruction of other tested nitrosamines exceeded NDMA destruction at the same collimated beam UV doses.

City of Oxnard's Advanced Water Purification Facility – An Example of Innovative Treatment Application and Design in Maximizing One Southern California Community's Long Term Water Resources

City of Oxnard's Advanced Water Purification Facility – An Example of Innovative Treatment Application and Design in Maximizing One Southern California Community's Long Term Water Resources

California Facility to Recycle Water for Farms, Landscaping, Groundwater Recharge

This article announces that CH2M HILL was selected to manage the design of an advanced water purification facility for the City of Oxnard, California, that will provide reclaimed water for landscape and agricultural irrigation, industrial process water, and groundwater recharge. The new facility is part of Oxnard's Groundwater Recovery Enhancement and Treatment program, which focuses on using existing water resources more efficiently.

N-nitrosodimethylamine (NDMA) removal by reverse osmosis and UV treatment and analysis via LC–MS/MS

N-nitrosodimethylamine (NDMA) is a probable human carcinogen found in ng/l concentrations in chlorinated and chloraminated water. A method was developed for the determination of ng/l levels of NDMA using liquid chromatography–tandem mass spectrometry (LC–MS/MS) preceded by sample concentration via solid-phase extraction with activated charcoal. Recoveries were greater than 90% and allowed a method reporting limit as low as 2 ng/l. Using this method, the removal of NDMA was determined for the Interim Water Purification Facility (IWPF), an advanced wastewater treatment facility operated by the Orange County Water District (OCWD) in Southern California. The facility treats effluent from an activated sludge treatment plant with microfiltration (MF), reverse osmosis (RO), and an ultraviolet-hydrogen peroxide advanced oxidation process (UV-AOP). Six nitrosamines were surveyed: NDMA, N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosodi- n-propylamine (NDPA), N-nitrosopiperidine (NPip), and N-nitrosopyrrolidine (NPyr). Only NDMA was detected and at all treatment steps in the IWPF, with influent concentrations ranging from 20 to 59 ng/l. Removals for RO and UV ranged from 24% to 56% and 43% to 66%, respectively. Overall, 69±7% of the original NDMA concentration was removed from the product water across the advanced treatment process and, in combination with blending, the final concentration did not exceed the California drinking water notification level of 10 ng/l. NDMA removal data are consistent with findings reviewed for other advanced treatment facilities and laboratory studies.

Prospects for creating in karakalpakstan wind electric stations of large capacity utilizing the wind energy resources of the Ustyurt Plateau

The prospects for creating a wind electric station (WES) of capacity 120 MW on the Ustyurt Plateau are examined; its fundamental parameters and operating characteristics are determined on the basis of the wind conditions recorded by the Zhaslyk weather station. The primary energy deficient consumers in the rural region of Karakalpakstan (the ungasified rural population centers, the electrical water purification facilities, and the pumping stations) are analyzed and the possibility for covering this shortage by the power that is generated by the WES is determined.

Applying non-metric multidimensional scaling analysis for measuring the assemblage change of Chu-Lan Creek dike in Taiwan

Ensuring that water resources development in harmony with aquatic environment is the major water policy of Taiwan in the 21st century, Taiwan's water authority has adopted several methodologies, such as utilizing ecological engineering techniques, establishing integrated water resources management configuration, involving the public in decision-making processes, etc., and applying them in the field. Significant consequences in ecological engineering were obtained in several cases, such as for Ta-Chia Creek, where wire cages, tires, and boulders were installed to improve the stream habitat, and for Wu-Lao Creek, where natural water purification facilities were constructed to reduce river pollution. Although the sustainable methodologies have been widely accepted by hydraulic engineers in Taiwan, lack of engineer-friendly evaluation indices or methods hindered the further progress of river ecological engineering projects. This research applied a non-metric multidimensional–scaling (MDS) analysis to measure the assemblage change of river aquatic habitat. A dike construction project at Chu-Lan Creek was selected for verification in this study. The analyzed results showed that the dike construction project did affect the aquatic habitat in Chu-Lan Creek. The proposed MDS analysis successfully captured the effect of the construction. The MDS method could be used to evaluate the improvement or damage of aquatic habitat by a traditional hydraulic approach or a new ecological hydraulic developed technique in Taiwan.

河川浄化施設における環境ホルモン類の低減効果

On-site water purification facilities have been employed to reduce suspended solid or organic pollutant concentration in river water, but their potential for removing micropollutants such as endocrine-disrupting chemicals (EDCs) has not yet been extensively investigated. Water quality tests on influent and effluent from treatment facilities using gravel contact oxidation were conducted. The removal ratios for nonylphenol and bisphenol-A exceeded 50%, with removal efficiency depending on operating conditions. Specifically, removal efficiency increased when longer hydraulic retention time (HRT) and aeration were applied. In addition to trapping a proportion of the suspended solids, adsorption and biodegradation in the facilities resulted in reducing the concentration of environmental endocrine disruptors.

三番瀬（東京湾）へ流入する排水種類別１人あたり水質汚濁負荷量と生活排水の環境家計簿

On the basis of papers and policy documents on pollutant loads, measures of dissemination and environmental education which highlights water pollution of an enclosed coastal sea, Sanbanze, Tokyo Bay, and a municipal life were proposed in this paper. Simple pollutant load analysis using water quantity and quality data available on websites of Chiba prefecture and its cities was conducted to examine what could be analyzed on the basis of data and information that can be easily accessed by an ordinary citizen. Pollutant loads per capita flowing into Sanbanze tidal coastal zone were calculated as 0.3-5.2g-COD person-1·day-1, 2.5-4.3g-N person-1·day-1 and 0.22-0.43g-P person-1·day-1 respectively. COD and T-N loads of “combined jokaso and riverside water purification facility” population and T-P load of wastewater treatment plants (WTPs) population were calculated as minimum of pollutant loads per capita flowing into water area are proposed as an effective index for domestic wastewater management, and the basic concepts of environmental accounting housekeeping (EAH) books for domestic wastewater are proposed for the purpose of information dissemination and environmental education as regards water pollution.

Process modelling evaluates feasibility of water recycling

The popularity of process simulation software in designing and evaluating the performance of water purification and wastewater treatment facilities is growing. Here, Demetri Petrides of Intelligen Inc, USA, talks about SuperPro Designer, a simulation programme that helped engineers at a semiconductor fabrication facility to assess process water recycling options.

Behavior of microcystins and its decomposition product in water treatment process

Microcystins are well known as a liver tumor promotors. Recently, we identified (2S, 3S, 8S)-3-amino-2,6,8-trimethyl-10-phenyldeca-4E, 6E-dienoic acid (DmADDA) as the decomposition product of microcystins by iron(III) chloride in vitro. Therefore, we measured the level of microcystins and DmADDA in the water purification facility for a year. DmADDA was not only detected in the surface water without toxic blue-green algae, but was also detected in the landing water and purified water. The levels of DmADDA were from ND to 1.82 μg/ml in the surface water, those in the landing water were from ND to 0.64 μg/ml, and those in the purified water were from ND to 0.42 μg/ml. The levels of microcystins (the value converted to microcystin LR) were from ND to 0.16 μg/ml in the surface water. Those in the landing water were from ND to 0.29 μg/ml and microcystins were not detected in the purified water during the year.