bluuebunny/crossref_metadata_2025 huggingface dataset:
Removal of organic matter by the PAC-UF process: first two years of a full-scale application
Authors: Baudin I. , Campos C. , Laîne J.M.
Published: May 2018

At the end of 1997, an innovative membrane-adsorption process was integrated at the Vigneux-sur-Seine water treatment plant in the southeast suburbs of Paris, France. This hybrid process consisted of the application of powdered activated carbon (PAC) upstream of ultrafiltration (UF) membranes and recycled to a floc blanket reactor (FBR) after membrane backwashes (FBR-PAC/UF process). This process was designed to mitigate seasonal episodes of micropollutants (pesticides and taste and odors) and to reduce the content of natural organic matter responsible for disinfectant and disinfection by-products. An intensive monitoring campaign of the plant effluent and ten sites in the distribution system was conducted two years before (1996-1997) and two years after (1998-1999) the start up of the PAC/UF process to characterize the impact of this treatment on the water quality of the distributed water. The objective of this paper is to illustrate the positive impact of the PAC/UF process on the organic and biological water quality of the Vigneux-sur-Seine distribution system. Thus, the combination of coagulation and adsorption in the FBR-PAC/UF process resulted in a TOC concentration lower than 0.7 mg/l, BDOC values lower than the detection limit (<0.2 mg/l) and total trihalomethanes concentrations below 10 μg/l. This reduction in organic content results in a reduction of the chlorine consumption by the water produced, which translates in the maintenance of higher chlorine residuals throughout the distribution system while using the same chlorine doses at the plant (0.3 mg/l).
Nylon screen incorporated into hollow fiber microfiltration system for wastewater treatment
Authors: Leow H.-F. , Bai R.
Published: May 2018

Low permeate flux due to clogging is the major challenge of hollow fiber microfiltration systems in wastewater treatment because of the high content of suspended solids. In this research, a new crossflow microfiltration module to overcome this problem was studied. The module consisted of a housing, a cylindrical membrane and a bundle of hollow fibers. The nominal pore size of the cylindrical membrane was 5 μm and that of the hollow fibers was 0.1 μm. The cylindrical membrane worked as a screen for pretreatment to remove those particles larger than its pore size and therefore to reduce the solid loading to the hollow fibers. Extensive experiments were conducted under various transmembrane pressures, influent concentrations, and crossflow velocities with polydispersed suspensions prepared with ISO Test Particles of size ranging from less than 0.5 μm to 10 μm. The quantity and quality of the filtrate were monitored over time. The results have shown that the cylindrical membrane worked effectively in reducing solid fouling, and therefore increasing permeate production for the hollow fiber microfiltration system.
High flux ultrafiltration membrane for drinking water production
Authors: Nakatsuka S. , Ase T. , Miyano T.
Published: May 2018

The high flux ultrafiltration hollow fibre membrane (HFCA) for drinking water production was developed and the membrane performance was evaluated by long-term ultrafiltration testing with river water. The hollow fibre membrane was made of cellulose acetate (CA) and has a highly porous structure with a very thin dense layer on the internal surface of the membrane. The ultrafiltration flux of the HFCA membrane was compared with that of the conventional CA membrane without such a highly asymmetric structure. The flux for the HFCA membrane was almost twice as high as that for the conventional one. The performance of the conventional CA membrane was also compared with that of membranes with different materials, namely polyethersulfone (PES) and polyacrylonitrile (PAN). The result showed much higher flux for the CA membrane, indicating that the fouling can be effectively controlled by using the membrane with hydrophilic and negatively charged properties. It was shown that the high flux for the HFCA membrane was due to characteristics of both membrane material and porous membrane structure. The pilot plant testing was carried out to examine the performance in the long term operation, and confirmed the high performance of the HFCA membrane for the application of drinking water treatment.
Performance of a hybrid MF membrane system combining activated carbon adsorption and biological oxidation
Authors: Suzuki T. , Watanabe Y. , Ozawa G.
Published: May 2018

The authors studied the performance of a hybrid MF membrane system combining activated carbon adsorption and biological oxidation for the removal of turbidity, natural organic matter, ammonia and manganese from river water in pilot-plant experiments. In this system, part of the soluble organic matter was adsorbed by the activated carbon. Ammonia and soluble manganese were oxidized by microorganisms that were concentrated in a submerged tank. In preliminary experiments, it became clear that powdered activated carbon (PAC) addition improved membrane permeability, because PAC has a large volume of macro-pores, which can adsorb larger molecular-weight organic matter. In the pilot-plant experiment, however, it was difficult to slow the rate of membrane permeability loss by PAC addition only. This may be due to biological fouling, caused by operating the system at a high recovery rate in order to maintain a high concentration of microorganisms in the submerged tank. Therefore, backwashing using hypochlorite solution (50-200 mg/l of Cl2) was carried out every few hours. This simple chemical washing was effective in preventing bio-fouling of the membrane.
Membrane filtration of high turbidity sources
Authors: Thompson M.A.
Published: May 2018

Membrane filtration processes have become widely used for low turbidity water sources that require particle removal and disinfection. In cases where the feed water contains high turbidity levels or high fouling tendencies, pre-treatment has been required to allow the membranes to operate efficiently. Submersion membranes have allowed direct treatment on many of these water supplies but operate under vacuum. This presents limitations on operating flux and design conditions for incorporating into existing facilities. The treatment unit designs are also very expensive to implement for small water treatment applications. A recently developed pressure driven ultrafiltration (UF) membrane is being tested on several different water sources and has demonstrated exceptional operation on high turbidity feed water sources. The module design includes a single potted end with the membrane fibers looped on the bottom to allow draining of solids from the module. The UF membrane filters outside to inside and has been operated on feed water turbidity levels up to 200 ntu. The availability of a pressure driven hollow fiber membrane that can efficiently filter high suspended solids water sources can provide a cost effective solution for many small to medium sized water supplies. Conditioning the feed water with a coagulant or direct filtration of high turbidity feed water can be used depending on the organic material present without settling or other clarification process. This eliminates the need for additional structural pretreatment and reduces overall system cost and size. Current limitations include the module size that makes this cost prohibitive for very large systems. Larger membrane systems where high-suspended solids are present in the feed water have been utilizing immersion membrane technologies more and more over the past few years. These systems typically operate under a vacuum and can be used for large water treatment plants as their design allows large filtration modules such as Memcor's CMFS filter block at 880 m3/hr. This allows significant capital cost reductions and allows membrane filtration to be competitive to conventional filtration technologies for virtually all filtration applications. This paper will review the economics and performance of both pressure driven and immersion membrane systems for small to large water supply systems on feed water containing high-suspended solid levels. Actual testing data for the new pressure driven hollow fiber UF membrane and immersion membrane systems will be provided on different water supplies including unconditioned surface water, filter backwash water and coagulated surface water.
Ultrafiltration combined with ozone for domestic laundry wastewater reclamation and reuse
Authors: Seo G.T. , Lee T.S. , Moon B.H. , Lim J.H.
Published: May 2018

Ozone was incorporated into an ultrafiltration system to produce higher quality reclaimed water from domestic laundry wastewater. Characteristics of the wastewater for initial washing waste were 488~2,847 mg/L COD, 62~674 mg/L MBAS, and 38~857 mg/L SS. The wastewater was contacted with ozone in a 10L storage tank and circulated through the membrane module for inner pressurized cross-flow filtration. The concentrate was returned back to the contact tank. The membrane used in this experiment was hollow fiber polysulfone UF membrane with MWCO 5,000 and 10,000. It has an effective filtration area of 0.06m2. The experiment was carried out in two phases with either continuous or intermittent ozone injection. For intermittent ozone injection, the mode of injection interval was changed to 5 min./5 min. and 5 min./10 min. for injection/idling. Ozone was dosed at the concentration of 1.5 mg/L. The permeate quality of UF (MWCO 5,000) was 57 mg/L as COD and 5 mg/L as MBAS at continuous ozone injection with removal of 95% in COD and 96.9% in MBAS. Using UF with MWCO 10,000, it was 93.7% and 95.5% of COD and MBAS, respectively. And using intermittent ozone injection, the removal efficiency was 93% in COD and 93.5% in MBAS without any deterioration in COD and MBAS removal. It could reduce the treatment cost. Using ozone injection, fouling of the membrane was also controlled by increasing organic degradation. The flux of UF (MWCO 5,000 and 10,000) was 0.13 and 0.20 m/d for 3 hour filtration (TMP 40≈45 kPa) without ozone injection. It was increased to 0.18 and 0.24m/d by ozone injection. The reclaimed water quality could be estimated well enough to reuse for rinsing purposes.
Residue-free removal of arsenic, iron, manganese and ammonia from groundwater
Authors: Rott U. , Meyer C. , Friedle M.
Published: May 2018

The paper presents a residue-free kind of water treatment process for the removal of metals like arsenic, iron and manganese and other water constituents like ammonia which may deteriorate drinking water quality. In this process the underground body, i.e. the aquifer, is used as a natural reactor. The results of field experiments of two technical-scale in-situ groundwater treatment plants are reported.
Partial demineralisation of drinking water using carbon dioxide regenerated ion exchangers
Authors: Höll W.H. , Hagen K.
Published: May 2018

CARIX is an ion exchange process which usually applies a mixed bed consisting of a weakly acidic and a strongly basic exchanger material. Carbon dioxide is applied as the only chemical for regeneration of the exchangers. As a consequence, the effluent contains only the amount of salt eliminated during the service cycle. CARIX allows a combined partial softening/dealkalisation/sulfate/nitrate of drinking water. A modification of the process uses exclusively a weakly acidic cation exchanger and allows a softening/dealkalisation. The process has been realised for drinking water treatment in five full-scale plants in Germany. Results of operation demonstrate that an excellent water quality is provided at fairly low cost.
UV/H2O2-treatment: the ultimate solution for pesticide control and disinfection
Authors: Kruithof J.C. , Kamp P.C. , Belosevic M.
Published: May 2018

Because of high contents of pesticides and micro-organisms in IJssel Lake water N.V. PWN Water Supply Company North Holland (PWN) was compelled to implement multiple barriers against these contaminants at their surface water treatment plants at Heemskerk and Andijk. For degradation of pesticides advanced oxidation was pursued. After thorough studies O3/H2O2-treatment was rejected in view of bromate formation. Subsequently application of UV/H2O2-treatment was pursued.

UV-photolysis shows a selective pesticide degradation. Conversion using an electric energy of 1 kWh/m3 varies from 18% for trichloroacetic acid to 70% for atrazine. UV/H2O2-treatment gives a much more aselective pesticide degradation. For a combination of an electric energy of 1 kWh/m3 and 15 g/m3 H2O2 most pesticides can be degraded by more than 80%. Formation of harmful by-products proved to be insignificant. In the range of 0.1-2.5 kWh/m3 electric energy and 0-25 g/m3 H2O2 bromate formation is absent, while metabolite formation is insignificant. AOC-formation is found up to 140 μg/l. Therefore AOC and residual H2O2 must be removed in a following treatment step. GAC-filtration showed very reliable results.

Application of UV/H2O2-treatment for pesticide control with an electric energy of 1 kWh/m3 goes together with an average UV-dose of 2,000 mJ/cm2. This dose is about 50 times as high as applied in conventional UV-disinfection. As expected E. coli and (after spiking) spores of sulphite reducing Clostridia are inactivated completely. In addition orientating experiments have been carried out with an UV-dose of 100 mJ/cm2. Inactivation of MS-2 phages amounted to 2.7 log, Bacillus spores inactivation to 3.4 log, while Cryptosporidium inactivation was complete (>3 log). Additional data are gathered together with the University of Alberta.

In view of the very promising results, application of UV/H2O2-treatment will be pursued for full scale application at both the Heemskerk plant for organic contaminant control and the Andijk plant for both organic contaminant control and disinfection.
Long term capacity of biological activated carbon filtration for organics removal
Authors: Bonné P.A.C. , Hofman J.A.M.H. , van der Hoek J.P.
Published: May 2018

Since March 1995 Amsterdam Water Supply has applied biological activated carbon filtration (BACF) in the treatment process of the Leiduin plant. In this plant (capacity 70 × 106 m3/y) pretreated River Rhine water is infiltrated in the dune area, west of Amsterdam, for artificial recharge. Post treatment comprises rapid sand filtration, ozonation, hardness removal, biological activated carbon filtration and slow sand filtration. At the start the carbon reactivation frequency was set at 18 months, based on removal efficiencies for AOX (adsorbable organic halogens), DOC, pesticides and micropollutants. After four years of operation of a pilot plant (10 m3/hour) in parallel with the full-scale plant, the remaining removal capacity and the break-through profile of the carbon filters was investigated. In contrast to the full-scale plant, no carbon reactivation was applied in the pilot plant during the operation of 4 years.

Spiking experiments were carried out after ozonation, in the influent of the biological activated carbon filtration with a cocktail of different pesticides after 1.5, 3 and 4 years. Influent concentrations varied between 2 to 10 μg/l. Without carbon reactivation the filter effluent still complies with the Dutch drinking water standards and guide lines, as well as with the Amsterdam Water Supply standards: DOC is less than 2 mg/l (actually 1.2 mg/l) and AOX remains below 5 μg/l.

After four years, with spiking concentrations of 2 μg/l still no pesticide break-through was observed in the two-stage biological activated carbon filtration process. It can be concluded that a running time of 3 years between two reactivations in the two stage biological active carbon filtration is achievable, without negatively affecting the finished water quality. Average DOC concentrations will increase up to 1.2 mg/l, from 1 mg/l with running times of 2 years. After four years or 100,000 bedvolumes the AOC content is equal to or lower than 10 μg/l after biological activated carbon filtration. With slow sand filtration at the end and as polishing step AOC will be less than 10-5 μg/l. With every extension of six months duration time a saving of Euro 305,000 on reactivation costs is possible. With every 6 month extension of the running time of the carbon filters a saving of €610,000 is realised on the reactivation costs of the Leiduin treatment plant.
Modelling and pilot plant investigations of high rate deep bed filtration with permeable synthetic filter media
Authors: Gimbel R. , Hahrstedt A. , Esperschidt K.
Published: May 2018

Permeable Synthetic Collectors (PSCs) are bodies of several millimetres consisting of a highly porous arrangement of fixed fibres or open-porous plastic foam. The advantages of the application of this media in deep bed filtration were studied. The theoretical analysis of the particle transport efficiency was based on the numerical solution of the flow field and on trajectory calculations for non-Brownian particles. Investigations with an endoscope allowed the consideration of the particle adhesion on the surface of the inner fibres. The resulting filter coefficients are compared with experimental data. The application of PSC filtration in a pilot scale unit for waste water treatment performs much better in contrast to conventional filter grains (sand, anthracite etc.), especially under high rate conditions. In the future, the deep filtration can be applied to new fields of the topic of solid-liquid separation with smaller units, lower pressure drop and higher filtration rates.
Removal of fluorides from water using low cost adsorbents
Authors: Nemade P.D. , Vasudeva Rao A. , Alappat B.J.
Published: May 2018

During the past few years, intensive interest in the problem of excessive fluorides in drinking water is a matter of serious concern around the world, as it causes fluorosis, a disease that affects teeth and bones. In India, the states of Rajasthan, Gujarath and Andhra Pradesh have a large number of villages where ground water contains excessive fluorides. India is among the 23 nations around the globe where health problems occur due to the consumption of fluoride contaminated water. Considerable research has been carried out to remove fluoride from the drinking water to overcome its toxic effect. This paper provides a review of the scientific literature on the varied aspects of fluorine chemistry, its occurrence, distribution and use of low cost adsorbents. Batch adsorption studies were carried out to determine the fluoride removal efficiency of fly ash, brick powder, wood charcoal, animal charcoal, fish bone charcoal, etc. Based on the efficiency, economy and usage of various low cost adsorbents specified above, the fish bone charcoal showed a comparatively higher fluoride removal than other adsorbents used. So that the problem of heavy fluoride in the drinking water in various states of India can be efficiently solved. Hence the dream of the WHO can be turned into reality and thus reduce hospital loads by 90%.
Pharmaceuticals degradation by UV and UV/H2O2 treatments
Authors: Bozzi A. , Lopez A. , Mascolo G. , Tiravanti G.
Published: May 2018

The degradation by UV and UV/H2O2 treatments of the pharmaceutical intermediate 5-methyl-1,3,4-thiadiazole-2-methylthiol (MMTD-Me) has been investigated and compared to that of its parent compound [5-methyl-1,3,4-thiadiazole-2-thiol (MMTD)] previously studied. The investigation has been carried out with a 17 W low pressure mercury lamp, at room temperature, with an initial MMTD-Me concentration of 1 mg/l and with a molar ratio H2O2/substrate of 100/1. The results show that: (i) the complete MMTD-Me removal is achieved within 60 and 20 minutes by UV and UV/H2O2 treatment respectively; (ii) the UV only irradiation does not cause any MMTD-Me mineralization; (iii) the UV/H2O2 treatment, after 4 hours, leads to a complete mineralization of MMTD-Me organic sulfur and to a partial mineralization of carbon and nitrogen (79 and 16% respectively). Degradation by-products identification, performed by HPLC-UV-MS, revealed that the UV only irradiation gives rise to the sequential transformation of MMTD-Me into two by-products one of which, the last one, accumulates in the solution. Conversely, the UV/H2O2 treatment leads to the formation of two intermediate by-products that undergo further degradation with the breakdown of the thiadiazole ring. These results confirm the effectiveness of UV based processes, alone or in combination with H2O2, in degrading pharmaceutical intermediates.
A hybrid biofilm reactor for nitrate and pesticide removal
Authors: Sakakibara Y. , Feleke Z. , Katahira T.
Published: May 2018

The feasibility of a hybrid biofilm reactor for nitrate and pesticide removal was demonstrated experimentally and theoretically. The reactor consists of an outer cylindrical cathode on which denitrifying autotrophic biofilm was attached and an inner anodic compartment packed with GAC. A bactericide, isoprothiolane (IPT), was used as a model pesticide, which inhibited the biological reduction step of N2O to N2. In the hybrid biofilm reactor, however, IPT was removed effectively by the GAC anode so that complete denitrification was achieved without accumulation of N2O. Simultaneous removal of nitrate and pesticide was evaluated by a mathematical model based on a simplified inhibition kinetics and Langmuir adsorption isotherm. Calculation results using the model were in fairly good agreement with experimental results.
Comparison of decay rates of faecal indicator organisms in recreational coastal water and sediment
Authors: Craig D.L. , Fallowfield H.J. , Cromar N.J.
Published: May 2018

A laboratory based microcosm study utilising intact non-sterile sediment cores was undertaken to determine the survival of the faecal indicator organisms Escherichia coli, Enterococcus faecium and somatic coliphage in both recreational coastal water and sediment. Overlying water was inoculated with the test organisms and incubated at 10°C, 20°C or 30°C. E. coli, enterococcus and coliphage were enumerated from the water column and sediment by the membrane filtration method, Enterolert (IDEXX Laboratories) and the double-agar overlay methods respectively on days 0, 1, 2, 7, 14 and 28 following inoculation. It was demonstrated that for all organisms, greater decay (k; d-1) occurred in the water column compared to sediment. Sediment characteristics were found to influence decay, with lowest decay rates observed in sediment consisting of high organic carbon content and small particle size. Decay of E. coli was significantly greater in both the water column and sediment compared with enterococcus and coliphage under all conditions. Decay of enterococcus was found to closely resemble that of coliphage decay. Survival of all organisms was inversely related to temperature, with greatest decay at 30°C. However, increased temperature had a less significant impact on survival of enterococcus and coliphage compared with E. coli. The importance of this study for estimating risk from recreational exposure is great if some pathogenic microorganisms behave similarly to the organisms tested in this study. In particular if survival rates of pathogens are similar to enterococcus and coliphage, then their ability to accumulate in coastal sediment may lead to an increased risk of exposure if these organisms are resuspended into the water column due to natural turbulence or human recreational activity.
Factors controlling nitrosamine formation during wastewater chlorination
Authors: Mitch W.A. , Sedlak D.L.
Published: May 2018

Recent discoveries of the formation of low levels of the potent carcinogen N-nitrosodimethylamine (NDMA) during wastewater chlorination has caused concern where indirect potable water reuse is practiced. Experiments indicate that nitrosamine formation during chlorination of wastewater is consistent with a reaction scheme involving the slow formation of a hydrazine intermediate from a secondary amine and monochloramine, followed by its rapid oxidation to the corresponding N-nitrosamine. A survey of precursors indicates that secondary amines form their corresponding N-nitrosamines to the greatest extent. However, molecules containing the secondary amine as a functional group can also form the corresponding N-nitrosamine. NDMA is the predominant N-nitrosamine found in chlorinated wastewater. However, other nitrosamines are detected. These N-nitrosamines may be important if the summed risk posed by the exposure to all N-nitrosamines is considered.
Contact filtration of humic waters: performance of an expanded clay aggregate filter (Filtralite) compared to a dual anthracite/sand filter
Authors: Saltnes T. , Eikebrokk B. , Ødegaard H.
Published: May 2018

Contact filtration performance of a coarse expanded clay aggregates filter (Filtralite) is compared to a conventional dual media anthracite/sand filter. In a contact filtration pilot plant, humic water was coagulated using aluminium sulphate (AS), iron chloride sulphate (ICS), poly-aluminium chloride (PAC) or the bio-polymer chitosan. Filtration experiments were performed at optimum pH and dose conditions for each coagulant found from previous optimisation experiments in the pilot filter plant. The results reveal two main problems in coagulation/filtration of humic waters: short filtration run times for the most commonly used metal salts, and metal residuals in treated water. The best ways to overcome these problems in raw waters high in organic matter, was found to be by the use of a coarse filter bed in combination with chitosan, or a metal salt with the addition of polymer as filter aid. An increased turbidity level in the raw water (as bentonite clay) was found to increase the removal of humics in most cases, as well as increase the filterability of the flocs formed.
Comparison of the fixation of several metal ions onto a low-cost biopolymer
Authors: Reddad Z. , Gérente C. , Andrès Y. , Le Cloirec P.
Published: May 2018

In the present work, sugar beet pulp, a common waste from the sugar refining industry, was studied in the removal of metal ions from aqueous solutions. The ability of this cheap biopolymer to sorb several metals namely Pb2+, Cu2+, Zn2+, Cd2+ and Ni2+ in aqueous solutions was investigated. The metal fixation capacities of the sorbent were determined according to operating conditions and the fixation mechanisms were identified. The biopolymer has shown high elimination rates and interesting metal fixation capacities. A pseudo-second-order kinetic model was tested to investigate the adsorption mechanisms. The kinetic parameters of the model were calculated and discussed. For 8 × 10-4 M initial metal concentration, the initial sorption rates (v0) ranged from 0.063 mmol.g-1.min-1 for Pb2+ to 0.275 mmol.g-1.min-1 for Ni2+ ions, with the order: Ni2+ > Cd2+ > Zn2+ > Cu2+ > Pb2+. The equilibrium data fitted well with the Langmuir model and showed the following affinity order of the material: Pb2+ > Cu2+ > Zn2+ > Cd2+ > Ni2+. Then, the kinetic and equilibrium parameters calculated qm and v0 were tentatively correlated to the properties of the metals.

Finally, equilibrium experiments in multimetallic systems were performed to study the competition of the fixation of Pb2+, Zn2+ and Ni2+ cations. In all cases, the metal fixation onto the biopolymer was found to be favourable in multicomponent systems. Based on these results, it is demonstrated that this biosorbent represents a low-cost solution for the treatment of metal-polluted wastewaters.
Managing chloramination - success story for Sydney water
Authors: Vitanage D.C. , Cresta P. , Doolan C. , Duker P.
Published: May 2018

Sydney Water's Woronora Delivery System periodically trialed chloramination over the last three years, with initial trials resulting in nitrification and bacteriological counts. A more planned and structured approach was used in June 2000 to reintroduce chloramination. The aim of the study was to assess the feasibility of chloramination as the preferred method of disinfection for the Woronora system, considering the impact on issues such as trihalomethane (THM) formation, nitrification, compliance performance and residual chlorine management. The implementation of chloramination and the optimisation of system hydraulics have resulted in significant improvements in water quality performance in terms of chlorine residuals, heterotrophic plate counts (HPC20), total and faecal coliforms and disinfection by-products. Higher chlorine residuals were seen throughout the system, taste and odour complaints were reduced to negligible levels, THM levels declined by two-thirds and nitrification was not evident at any stage throughout the trial. A critical control matrix was developed as a vital management tool to address the issues that could impact on chloramination/nitrification in the system. Managing the nitrification balance in terms of the available ammonia and maintaining the chlorine to ammonia ratio close to 4:1 (as Cl2:NH3) within the total system and the maintenance of a higher residual chlorine level (>1.00 mg/L) were found to be the most critical factors in managing a chloraminated system.
Evaluation of drinking water treatment processes focusing on natural organic matter removal and on disinfection by-product formation
Authors: Chae S.
Published: May 2018

The aim of this study was to characterize and compare natural organic matter (NOM) removal and disinfection by-product (DBP) formation in the drinking water treatment train that can give valuable information, while optimizing the treatment process. In this study, the determination of the hydrophobic (HPO), transphilic (THP) and hydrophilic (HPI) NOM distribution was used in parallel with more related drinking water parameters to compare the selected waters. High-performance size-exclusion chromatography (HPSEC) was applied to evaluate the relative changes of molecular size distribution of NOM in different treatment steps and source waters. This showed that the quantity, speciation and activated carbon adsorption of DBPs could vary not only by water quality, but also by the distribution and properties of the organic molecules that comprise NOM.
Potable reuse of wastewater effluent through an integrated soil aquifer treatment (SAT) - membrane system
Authors: Jarusutthirak C. , Amy G. , Foss D.
Published: May 2018

Soil aquifer treatment (SAT) has been shown to provide significant reductions of wastewater effluent organic matter (EfOM). While SAT can renovate wastewater effluent to levels commensurate with potable reuse, SAT represents only a single treatment barrier. Membrane filtration has been demonstrated to be an alternative treatment process for wastewater reclamation. However, the performance of membrane filtration is significantly constrained by membrane fouling, reducing membrane productivity in terms of flux decline. Soil aquifer treatment (SAT) is used as a primary barrier in the reclamation system to remove a complex suite of chemical and biological contaminants in wastewater. This study of membrane filtration of SAT-source waters is intended to determine the benefits of the SAT system in terms of membrane fouling reduction with membrane filtration providing a secondary barrier. Membrane treatment of SAT-recovered water provides a multiple barrier exhibiting additional organic matter removal. Moreover, the SAT system also provides for storage of reclaimed water. The synergy between SAT and membrane treatment has led to the concept of an integrated SAT-membrane system for potable reuse.
Rouse Hill and Picton Reuse Schemes: innovative approaches to large-scale reuse
Authors: Cooper E.
Published: May 2018

Driven by concerns centred on the potential impacts of new development on the Hawkesbury-Nepean River, the management of effluent from Sewage Treatment Plants is a growing issue for regulators, communities and Sydney Water Corporation. Conventional users of recycled water such as golf courses, parks and on-site uses are making way for more innovative and sustainable approaches. Rouse Hill Recycled Water Plant and the Picton Agricultural Reuse Schemes are two examples where Sydney Water has adopted a different approach to water recycling. With both schemes now in operation, demand for the product has surpassed expectations and has already begun to exceed current availability. Faced with the option of expanding the schemes in the near future, SWC is continuing to look for new ways of providing sustainable water services to the people of Sydney.
Wastewater reuse and treatment options for the dairy industry
Authors: Baskaran K. , Palmowski L.M. , Watson B.M.
Published: May 2018

Milk-processing plants generate significant quantities of wastewater with relatively high organic matter concentrations on a daily basis. In addition to environmental damage that can result from the discharge of these wastewaters into the natural waterways, the presence of products such as milk solids into wastewater streams represents a loss of valuable product for the plants. This paper presents a review of wastewater management practices employed by six milk-processing plants in Victoria, Australia. In all six plants investigated, milk powder represents a major product. During the milk powder production, water is evaporated, condensed and can be reused for various purposes with a significant impact on water usage. Other major products are anhydrous milk fat, cheese, butter, and UHT milk.

The effectiveness of the practices was assessed through two main criteria: first through the water to milk intake ratio, and the waste volume coefficient. Both parameters characterise the plant efficiency in regard of water consumption and water reuse. Information on cleaning chemical usage and recovery was also assessed as part of the review. Significant discrepancies emerge between the plants first due to the products manufactured and water reuse possibilities available in each plant. Second the type of treatment technologies used for condensate and cleaning solution influences the figures. One of the investigated plants is almost self-sufficient for water, emphasising the benefits gained from the use of technologies like membrane separations for condensate and cleaning solution treatment. In some cases, less cost-intensive technologies such as a clarifier are successful to improve cleaning agent recovery.
Public receptivity regarding “in-house” water recycling: results from a UK survey
Authors: Jeffrey P. , Jefferson B.
Published: May 2018

Whilst the development of suitable technologies which provide opportunities for water recycling has moved on apace over the past decade, their practical application will not depend solely on effective and reliable engineering performance. Successful employment of preferred strategies and technologies will require an understanding of the social environment in which they are to be applied. The study reported below explores some of the attitudinal determinants of public acceptance of water recycling in the UK. Findings show that there is broad willingness to accept in-house water recycling as long as public health is not compromised.
Case studies on municipal wastewater reclamation and reuse in China
Authors: Wang B. , Wang L. , Li G. , Qi P. , Liu Y.
Published: May 2018

Water shortage and water environmental pollution have promoted the development of wastewater reclamation and reuse in China in recent years. Different treatment processes are employed for this purpose, such as pond-farmland systems using solar radiation as initial energy source, treating wastewater at low cost and low energy consumption to realize wastewater reclamation and reuse for irrigation on farmland to provide both water and nutrients. Some full-scale projects on municipal wastewater reclamation mainly based on activated sludge and/or submerged biofilm processes followed by some advanced treatment processes such as filtration and disinfecting, from which the effluent is reused in agriculture, industry and domestic uses except for drinking purpose have been built and put into operation in some water shortage cities, which are described in this paper. In some water scarce cities the domestic wastewater reclamation and reuse (dual water system) is employed for a building, a group of buildings or a sub-residential district, whose treatment system consists of submerged biofilm process, dual-media filter and disinfection.
Production of high quality water for reuse purposes: the West Basin experience
Authors: Lazarova V. , Sheilds P. , Levine B. , Savoye P. , Hranisavljevic D. , Renaud P.
Published: May 2018

Water reuse is becoming an essential factor for developing sound water and environment managaement policies, The main challenge for the operators of water reuse facilities is to increase the cost-efficiency and reliability of water reuse systems. To achieve this objective, an R&D program has been implemented at the West Basin Recycling Plant in California to study the removal of trace organics by advanced treatment (UV disinfection, membrane filtration). The pilot studies demonstrated the efficiency of two UV systems for final disinfection and in particular its high performance for the MF/RO effluent at low UV doses. UV appears as a cost competitive alternative to chlorination; it prevents the generation of toxic chlorinated by-products and reduces the salt content. It was demonstrated that microfiltration, as a replacement of conventional lime pretreatment for reverse osmosis, also offers numerous advantages. Despite the improved removal of trace organics, the membrane pretreatment before RO leads to a saving of 45% of life costs.
The use of levelised cost in comparing supply and demand side options
Authors: Fane S. , Robinson J. , White S.
Published: May 2018

This paper explores the use of levelised cost in planning for infrastructure networks. Levelised cost provides a useful measure comparing supply or conservation options on varying scales on an equivalent basis. Comparison is made to annualised cost, a metric often used as a means of comparing different supply side options. Urban water supply is used as the primary example, however levelised cost is equally applicable to other infrastructure networks, such as electricity or gas. The levelised cost is calculated as the ratio of the present value of projected capital and operating cost of an option to the present value of the projected annual demand supplied or saved by the option. The paper demonstrates that levelised cost is the constant unit cost of supply, provided by an option at present value. It is also the average incremental cost of the option at the point of implementation. When translated to a unit cost, annualised cost does not account for unutilised capacity in large scale schemes, systematically under-representing actual costs. By using levelised cost this inherent bias is removed. Use of levelised cost would facilitate the inclusion of smaller scale and more incremental supply options into infrastructure networks providing both economic and environmental benefits.
Benefits of the United States nationwide plumbing efficiency standards
Authors: Dickinson M.A. , Maddaus L.A. , Maddaus W.O.
Published: May 2018

In 2000, the American Water Works Association (AWWA) and California Urban Water Conservation Council partnered to study the merits of the United States National Plumbing Efficiency Standards. The study develops information on the value of the national plumbing standards, based on a nationwide survey of water supply utilities. Using base year 1999 water production levels, the study found forecasted water production due to the national plumbing code reduced by 5 per cent in 2010, climbing to 8 per cent water savings by 2020. Average utility savings of US$26 per person extrapolated to the United States as a whole amount to about US$7.5 billion in reduced infrastructure costs due to the national plumbing code. Including energy benefits from hot water savings, the total dollar savings to communities is higher at US$35 billion in the United States. This paper highlights an example methodology into the overall assessment of water and cost savings from water conservation programs. This methodology, more fully presented in the original report document, is particularly useful for water agencies quantifying benefits when seeking to avoid acquiring new source water supplys and/or defer building capital projects.
Watersmart - developing a sustainable water resources strategy for Melbourne
Authors: Young R.
Published: May 2018

Melbourne's water supply system has developed incrementally since the 1850s in response to the demands placed on it by a growing city. As Melbourne has continued to grow, a number of water supply strategies have been undertaken to identify options for meeting future water demands. The last major strategy review was undertaken in 1992. In October 2000, the Victorian Government, through the Minister for Environment and Conservation, announced the establishment of a Committee to oversee the development of a sustainable 50 year water resource management strategy for Melbourne's water supply system. This paper outlines the process undertaken in developing the strategy, including; the development of the Discussion Starter report which provided background information on the four broad options identified to manage Melbourne's water resources, the consultation process adopted to obtain community views on preferences and the next steps in the development of the strategy.
Agriculture, water and the environment: future challenges
Authors: Oron G.
Published: May 2018

Various countries in the Mediterranean Basin and other arid and semi-arid regions are facing a gap between water supply and demand. This gap is closely linked with agricultural production and environmental issues. It is probably due to small amounts of precipitation and low availability of natural water sources. Special ventures have to be undertaken in order to supply water at adequate quality for all requirements. These can be accomplished by development of additional water sources that currently are considered marginal. The additional sources include saline ground water, treated wastewater and runoff water and are usually required to augment the limited supply from the regional conventional high quality local sources. The paper presented options for development of the marginal water sources in arid zones in conjunction with minimizing the dependence on high quality water. Domestic secondary effluent is a valuable water source for reclamation however, additional treatment is required to use it for unrestricted purposes. It can be achieved primarily by implementation of the membrane technology, namely ultrafiltration (UF) and reverse osmosis (RO) stages.
Challenges and prospectives for water recycling and reuse in EU countries
Authors: Angelakis A.N. , Bontoux L. , Lazarova V.
Published: May 2018

Recycled water is a reliable source of water that must be taken into account in formulating a sustainable water policy. Water reuse is a growing field and many projects have been occurring throughout Europe in the last fifteen years. Most of northern EU countries have abundant water resources. In this case, the need for extra supply through the reuse of treated wastewater is not a priority, but the protection of the receiving environment is considered as an important issue. The situation is different in the southern EU countries, where the additional resource brought by water reuse promoted the implementation of a number of new projects. One of the major constraints for water reuse and its public acceptance is the lack of relevant legislation at EU level. As a result of this situation, both strict and flexible standards can be found in Europe, even in the same country (Spain, for example), illustrating an important equity issue, which needs to be addressed.
Using recycled water for non-potable, urban uses: a review with particular reference to toilet flushing
Authors: Lazarova V. , Hills S. , Birks R.
Published: May 2018

This paper summarises the current non-potable, urban use of reclaimed water with particular reference to toilet flushing. It compares water quality standards for reclaimed water, the volumes of water required for toilet flushing and the qualities of greywater and domestic sewage that have previously been used for reuse. Worldwide examples of reuse schemes are presented with particular detail to two key European sites where greywater has been used for toilet flushing, the Millennium Dome in the UK and a residential block of flats in Annecy, France. It was demonstrated that the interest in water reuse is growing steadily, not only in acknowledged water deficient areas, but also in countries which have not historically appeared to have a water supply problem. The latter include Northern European States such as Belgium, France, the UK and Germany, as well as in tourist coastal areas and islands. This situation affords great opportunities for the creation of urban water recycling schemes.
Slow granular filtration for water reuse
Authors: Adin A.
Published: May 2018

The slow sand filtration (SSF) design parameters as known for purifying surface water cannot be copied for the treatment of secondary effluents. The objectives of the present research were to examine the possibility of slow granular filtration (SGF) as advanced treatment of secondary effluents for reuse purposes and examine filter performance under various design regimes. Slow granular filtration runs where made with four different filters at rate of 0.15 m/h. 0.6 mm, 0.25 mm sand or tuff grains or their combination were used. Grain size of 0.25 mm gave low impurities concentration in the effluent but short filtration runs. Double layer bed caused longer filtration run as well as lower impurities concentration in the effluent, Combining the tuff as the top bed layer caused longer filtration run, probably due to the morphologic and chemical properties of the tuff. The water column above the bed plays an important role in the filtration process. Intense microbiologic activity in the column changes the TSS and COD concentration as well as the availability of the biodegradable matter. The dissolved oxygen concentration in the water column above the bed, and in the bed depth can serve as a good indicator for ripening of the biological layer.
Optimisation of the use of nitrogen in the treated wastewater reused for irrigation
Authors: Papadopoulos I. , Savvides S.
Published: May 2018

Application of recycled water to agricultural land for irrigation could be an alternative water resource for Mediterranean countries facing severe water shortage. Rational use of the nutrients in recycled water could increase crop production and reduce environmental pollution. This study was designed to investigate the effect of treated wastewater and N applied on the yield of three field crops. Three experiments with green pepper, eggplants and sudax, irrigated with borehole water or with secondary treated municipal wastewater, were carried out in a field experiment. Both waters were supplemented with N applied continuously with the irrigation water at four levels 0 g/m3, 50 g/m3, 100 g/m3 and 150 g/m3. Yield results indicate the superiority of the treated wastewater and its ability to produce high yields with less N fertilizers.