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Water resources around the world are under increasing pressure from the rapidly growing demands of rising population and industrialization. Furthermore, changes in global weather patterns are expected to intensify its current and future stresses. In the present study, knowledge and perceptions towards wastewater reclamation for potable and non-potable uses were investigated by the used of an on-line survey distributed amongst the university community at Western university. Subsequent statistical analysis of the results was performed using IBM-SPSS software. Survey results show that member of the university community are more likely to accept reclaimed wastewater for applications that do not involve drinking or close personal contact. However, acceptability improves when benefits to the environment are extensive, it is safe for humans, the source of reclaimed water is perceived as cleaner than municipal wastewater, and the reclaimed wastewater is put back into natural systems with long retention times such as aquifers. Knowledge of the urban water cycle and water resources in Canada is moderate among the university community and the Gamma measure of association shows that there is a moderate (0.303) positive relationship between “water knowledge” and “close contact acceptability”. The majority of the university community (75.8 %) thinks that reclaiming water to provide an alternate source of water in southwestern Ontario is a good idea, but there are still concerns with the presence of chemicals such as pharmaceuticals from reclaimed water and the long-term effects on human health from exposure to these contaminants. Additionally, the suitability of the predominant soils of southwestern Ontario for Soil Aquifer Treatment (SAT) of secondary effluents and combine sewers overflows (CSOs) was investigated by the use of a laboratory scale SAT system operated at three hydraulic retention times. Samples were analyzed for dissolved nitrate, sulphate and phosphate ions, ammonia nitrogen, total nitrogen, total coliforms, E. coli, dissolved organic carbon (DOC), dissolved oxygen and biological oxygen demand (BOD5). Results show that prevalent soils of southwestern Ontario have the ability to further polish secondary effluents in terms of organic matter, E.coli and total coliforms. However, issues with the persistence of nitrates affects its suitability for potable aquifer recharge. Quality of CSOs was slightly improved, however sustainable SAT for non-potable or potable aquifer recharge is not achievable due to low removal of biological contamination, potential for high nitrate concentrations in the effluent and media clogging.

In recent years water scarcity has become more prominent, increasing the need for new practices in terms of efficient water management. Reuse and valorization of water from wastewater treatment plants (WWTPs) can help solve the problem.The traditional denitrification/nitrification scheme followed by a natural disinfection/storage tank has been studied in order to optimize the process for irrigation reuse. The study is based on data produced by an experimental pilot-scale plant, located in Trebbo di Reno (BO, Italy) and from a recent field campaign carried out on internal fresh water of the Allacciamento Channel inside the basin of Porto Canale Cesenatico (FC, Italy). Using WEST software to model the first phase and a dispersed flow equation to model the Escherichia coli (E. coli) removal rate in the following basin, the overall process has been optimized to test the capacity of a Business Process Management (BPM) approach to model the water storage management for irrigation reuse.High pollutants removal efficiencies and a water storage system able to fulfill the irrigation needs are two essential requirements for water reuse. The study shows how to achieve those aims using a combined system with a natural disinfection basin analyzing the hydraulic parameters effects on pollutants removal throughout the water column. Moreover, the management optimization of the process has been studied suggesting different management policies for different scenarios.

This work reports an extendible multiobjective optimization framework to find the optimal configuration of energy utilization and wastewater treatment facility of the process. It incorporates two sustainable energy integration alternative tools, i.e., a cogeneration (COGEN) unit and thermal membrane distillation (TMD), as available add-ons to the process during normal operation and for abnormal situation management. The objective of the framework is to reduce the environmental footprint of abnormal flares by enumerating and assessing possible process configurations in order to manage flares from uncertain sources and to utilize unused energy resources for wastewater treatment. The core of this optimization framework is developed using a genetic algorithm and its objective function is aimed at minimizing the total annualized cost which accounts for the fixed and operating costs of the system, the value of produced coproducts (i.e., power, wastewater treatment savings, income from permeate), and taxes/credits associated with greenhouse gases. An ethylene process plant is used to demonstrate the applicability of the developed framework. The results of different alternative configurations demonstrate the economic, energetic, and/or environmental trade-offs of integrating TMD and the COGEN unit with the process plant both for flare mitigation and during normal operation. It was seen that the total annualized cost (TAC) dropped around 35% and the payback period reduced from 7.01 to 4.61 years when an integrated process plant (ethylene plant), utility unit (COGEN), and wastewater treatment facility (TMD) was considered instead of separate divisions. Moreover, utility savings were achieved up to 8% and annual incomes from coproducts were increased around 20% for the integrated ethylene plant, COGEN, and TMD unit. Besides, prolific recycling opportunities of unused flare streams and treated wastewater were identified to make some valuable products from waste streams. Scopus

The Choshui river basin, the mother river in Taiwan, suffers from severe water shortage from extensive water use in irrigation as well as land subsidence from over-pumping of groundwater. To address these challenges, several water-related strategies and actions, including enhancement of water-use efficiency, development of alternative water sources, and improvement in effective water management, were proposed in this study to support sustainable water resource management in the watershed. Management of water resources in Taiwan is expected to confront not only freshwater resource but also energy source constraints. Multi-criteria decision analysis (MCDA), an approach for ranking overall performances of decision options, was then used to prioritize the water resource management strategies. The analysis considered economic (economic feasibility) and environmental (stability from the influence of climate change) criteria in the context of water&ndash, energy nexus (water supply/conservation potential and systemic energy efficiency). Our results indicated that, while economic feasibility was considered as the most important factor in implementation of the practices, improvement in groundwater pumping control and management was ranked as a high-priority water resource management action, followed by initiating water conservation programs for residential sector and reducing leakage rate for agricultural irrigation canals. The results from this study are expected to provide direction for future decision making in water resource management.

Following increasing interest in the use of UltraFiltration (UF) membrane processes as an alternative advanced disinfection technique, the performance of a UF pilot plant was investigated under two opposite operating conditions (“stressed operating condition” versus “conventional operating condition”). The results indicate that for both conditions, the reclaimed effluent complied with the Italian regulations for unrestricted wastewater reuse (i.e., Total Suspended Solids (TSS) < 10 mg/L; Chemical Oxygen Demand (COD) < 100 mg/L and Escherichia coli < 10 CFU/100 mL). On the other hand, when compared with the Title 22 of the California Wastewater Reclamation Criteria, only the effluent produced under the “conventional operating condition” met the stipulated water quality standards (i.e., TSS and turbidity undetectable and total coliforms < 2.2 CFU/100 mL). It should be noted that, in spite of the nominal cut-off size, total coliforms breakthrough was indeed occasionally observed. A localized membrane pore micro-enlargement mechanism was hypothesized to explain the total coliforms propagation in the ultrafiltered effluent, as monitoring of the membrane permeability and transmembrane pressure highlighted that gel/cake formation had only a minor contribution to the overall membrane fouling mechanism with respect to pore plugging and pore narrowing mechanisms.

Managed Aquifer Recharge (MAR) is becoming an attractive option for water storage in water reuse processes as it provides an additional treatment barrier to improve recharged water quality and buffers seasonal variations of water supply and demand. To achieve a better understanding about the level of pathogenic microorganisms and their relation with microbial indicators in these systems, five waterborne pathogens and four microbial indicators were monitored over one year in three European MAR sites operated with reclaimed wastewater. Giardia and Cryptosporidium (oo)cysts were found in 63.2 and 36.7% of the samples respectively. Salmonella spp. and helminth eggs were more rarely detected (16.3% and 12.5% of the samples respectively) and Campylobacter cells were only found in 2% of samples. At the Belgian site advanced tertiary treatment technology prior to soil aquifer treatment (SAT) produced effluent of drinking water quality, with no presence of the analysed pathogens. At the Spanish and Italian sites amelioration of microbiological water quality was observed between the MAR injectant and the recovered water. In particular Giardia levels decreased from 0.24-6.14 cysts/L to 0-0.01 cysts/L and from 0.4-6.2 cysts/L to 0-0.07 cysts/L in the Spanish and Italian sites respectively. Salmonella gene copies and Giardia cysts were however found in the water for final use and/or the recovered groundwater water at the two sites. Significant positive Spearman correlations (p

Reclamation and reuse of wastewater is one of the most effective ways to alleviate water resource scarcity. In many countries very stringent limit for chlorination by-products such as trihalomethanes has been set for wastewater reuse. Accordingly, the use of alternative oxidation/disinfection systems should be evaluated as possible alternative to chlorine. Recently ultrasound (US) was found to be effective as pre-treatment for wastewater disinfection by UV irradiation. The aim of this work is to investigate the wastewater advanced treatment by simultaneous combination of UV and US in terms of bacteria inactivation (Total coliform and Escherichia coli) at pilot-scale. The pilot plant was composed of two reactors: US-UV reactor and UV reactor. The influence of different reaction times, respective US and UV dose and synergistic effect was tested and discussed for two different kinds of municipal wastewater. An important enhancement of UV disinfection ability has been observed in presence of US, especially with wastewater characterized by low transmittance. In particular the inactivation was greater for T. coliform than for E. coli. Furthermore, the results obtained showed also that the fouling formation on the lamps was slower in US-UV reactor than in UV reactor both with and without solar radiation.

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2015, Thesis (M.Sc.) -- İstanbul Technical University, Instıtute of Science and Technology, 2015, Artan su ihtiyacı, tükenen ve kirlenen su kaynakları nedeniyle mevcut su kaynaklarının akıllıca kullanılması, kirlenmelerinin önlenmesi gerekmektedir. Ayrıca atıksuların klasik sistemlerle arıtılıp su kaynaklarına deşarj edilmesi yerine membran biyoreaktör gibi ileri atıksu arıtma teknolojileri ile arıtılıp geri kazanılarak tekrar kullanılmaları su kaynaklarının geleceği bakımından çok önemlidir. İ.T.Ü. Çevre Mühendisliği Laboratuvarı’nda pilot ölçekli batık membran biyoreaktör sistemi kurulmuştur. Hans Huber AG firmasından alınan MembraneClearBox® (MCB) adlı membran biyoreaktör sistemi, aktif çamur prosesi ve daldırılmış ultrafiltrasyon (UF) membranları vasıtasıyla arıtılmış suyun ayrılması işleminin birleşimi olan bir arıtma sistemidir. Membran modülü plaka-çerçeve tipli olup ultrafiltrasyon membranıdır, por büyüklüğü 38 nm olup 9 adet membran plakası bulunmaktadır ve toplam yüzey alanı 3.5 m2’dir. Membran biyoreaktör sistemi kompakt bir sistem olup üzerinde bulunan ekipmanlar hava bloweri, scouring (sıyırma) bloweri, debi ölçer, numune alma vanası, basınç ölçer ve kontrol ekranıdır. Sistem ayarlamaları kontrol ekranı vasıtası ile yapılmaktadır. Sistemde normal işletme modu, ekonomi modu ve yüksek yük modu olmak üzere üç adet işletme modu bulunmaktadır. Sistem normal şartlarda normal modda işletilir, membran biyoreaktöre atıksu girişi olmadığı zamanlarda ise (tatil zamanları) mikroorganizmaların ölmemeleri için gereken minimum oksijen sağlanmaktadır. Yüksek yük modu ise sisteme aşırı yük geldiği durumlarda kullanılmaktadır. Orta karakterli evsel atıksu niteliğinde sentetik atıksu ile çalışmalar yürütülmüştür. Ham atıksu giriş değerleri KOİ, BOİ, Toplam Azot (TN) ve Toplam Fosfor (TP) için sırasıyla 500 mg/L, 400 mg/L, 40 mg/L ve 8 mg/L’dir. Ham atıksuyun C:N:P oranı 100:8:1.6’dır ve bu değer ideal değer olan 100:5:1 değerine oldukça yakındır. Daha gerçekçi olması bakımından sentetik atıksu ideal değerlere uyacak şekilde hazırlanmamıştır. Önce anaerobik besleme tankına (fosfor giderimi için gereklidir) gelen atıksu peristaltik pompa vasıtasıyla reaktöre girer. MBR içerisinde kesikli havalandırma sayesinde karbon giderimi, nitrifikasyon ve denitrifikasyon işlemleri gerçekleşmektedir. MBR sistemi geri devirli ve geri devirsiz olmak üzere iki farklı tipte işletilmiştir. Geri devirsiz işletme süresince elde edilen giderme verimleri sırasıyla AKM, KOİ, BOİ, TN, TP, Ca+2, Mg+2, Na+, CI- ve toplam koliform parametreleri için % 99.97, % 98, % 98, % 60, % 40, % 2.4, % 3.4, % 0.55, % 67 ve % 100’dür. Geri devirsiz arıtma için ise AKM, KOİ, BOİ, TN ve TP giderme verimleri sırasıyla % 99.98, % 99.28, % 98.3, % 66 ve % 60’dır. Elde edilen sonuçlara göre geri devirli arıtma verimleri kısmen daha iyidir. MBR sistemindeki MLSS konsantrasyonu işletme süresince 7356 mg/L’ye kadar yükselmiştir. Reaktördeki ortalama iletkenlik, MLSS, sıcaklık, pH ve çözünmüş oksijen değerler sırasıyla 7121 µS/cm, 4935 mg/L, 20.63 ºC, 5.64, 1.07 mg/L’dir. Elde edilen çıkış suyu sulama suyu olarak (tarımsal, yeşil alan, peyzaj, golf sahası) kullanılabilir. Ayrıca yangın söndürme, araç yıkama ve sifon suyu olarak da kullanılabilmektedir. Sulama suyu olarak kullanımda sulanacak bitki türü ve toprak yapısı oldukça önemlidir ve dikkatle seçilmelidir., There is an increasing water demand in the world and water supplies keep getting polluted, so it is necessary to prevent further contamination and planned usage of available clean water resources. In addition, instead of classic wastewater treatment systems we should use advanced wastewater treatment systems like membrane bioreactor and reuse the treated wastewater. Pilot scale submerged membrane bioreactor system (SMBR) was set up in the I.T.U. Environmental Engineering Department Laboratory. MembraneClearBox® (MCB) MBR system was bought from Hans Huber AG firm and it is a hybrid system combined with classical activated sludge proses and submerged UF membrane module. Type of the membrane module is plate-frame and pore size of the membrane is 0.38 nm (UF membrane). There are 9 plates and total membrane area is 3.5 m2. Volume of the feed tank was 200 L. Volume of the membrane bioreactor always was kept fixed at 500 L while operation time. Experiments were conducted with synthetic wastewater which prepared as medium strength domestic wastewater. It assumed that the source of untreated wastewater was only domestic and there was no industrial discharge to that water, so it was not contain any toxic chemicals and heavy metals. COD, BOD, TN and TP values of the influent synthetic water was 500 mg/L, 400 mg/L, 40 mg/L and 8 mg/L respectively. C:N:P ratio of the wastewater was 100:8:1.6, that ratio was very close to the ideal C:N:P ratio of 100:5:1. The synthetic wastewater could be prepared like ideal ratios but that was not done because of being more realistic. Operation of the system was all automatic and it could be customized by electrical control monitoring unit. In the operation system there were an air blower, scouring blower, flow meter, permeate pump, sampling valve, pressure meter. System worked with negative transmembrane pressure and the pressure value could be seen all the time while operating. Scouring blower supplied air for preventing membrane fouling, scouring blower time could also be changed on the control unit. When permeate flow is too low (when fouling increased) the scouring blower started running automatically. If fouling is too much scouring blower could not be efficient sometimes. If the scouring blower worked 5 times in 1 minute, system stopped filtering the water. When that happened, the membrane needed chemical cleaning. Since it was a plat-frame membrane module, chemical backwash could not be done automatically. Chemical cleaning was done manually by giving the solution through permeate pipe backward. Sodium hydroxide (NaOH) and citric acid solutions were used as chemical cleaning agents. When permeate flow was too low, system stopped and chemical washing was done manually and after sometime system started to work again. When chemical washing was done wastewater did not filtered and enter into the membrane bioreactor system. There were 3 mode option in the operation system. Economy mode, normal mode and high load mode. Economy mode especially could be used for the vacation times when there was no wastewater entrance in the membrane bioreactor, minimum oxygen demand was supplied, so microorganism did not die. Normal mode was used when there was entrance and effluence of the wastewater to the membrane bioreactor and it could be used for normal operation times. High load mode could be used when there was more wastewater entrance of the wastewater than usual. MLSS concentration in the membrane bioreactor was very low initially, so experiments was not started until higher MLSS values. In treatment process, wastewater enters the anaerobic feed tan first (which required for the biological phosphorus removal) and pumped to the membrane bioreactor via peristaltic pump, feed tank also worked as a sedimentation tank and solid particles can settle in the bottom of the tank. Blower of the reactor turns on and off automatically so there can be carbon removal, nitrification and denitrification processes. On and off time, system modes could customized. Oxygen was not given continuously because denitrification process was necessary for the nitrogen removal, all processes happened in one tank (membrane bioreactor). There were probes for measuring dissolved oxygen, MLSS, pH, electrical conductivity and temperature all the time in the membrane bioreactor. Water level of the reactor had always kept stable. The MBR system was operated in two different modes, one was with no recycle of the sludge and the other one was with recycle of the sludge to the feed tank. Sludge was never discharged from the system. Sludge age was infinity for both operating modes. Mixed liquor suspended solids (MLSS) concentration in the membrane bioreactor increased to the level of 7356 mg/L (highest value) and changed between 800 mg/L and 7356 mg/L during the experimental work. Mean values of the conductivity (EC), temperature, pH, dissolved oxygen (DO) and MLSS were 7121 µS/cm, 20.63 ºC, 5.64, 1.07 mg/L and 4935 mg/L respectively in the membrane bioreactor. When sludge was returned from the membrane bioreactor to the feed tank, MLSS concentration started to decrease because biomass was also returning to the feed tank too. Electrical conductivity (EC) value was high and there were some reasons for that. One of the reasons was addition of the sodium hydroxide (NaOH) to the membrane bioreactor for adjusting the pH value, because of the reactions in the membrane bioreactor tank pH value tented to get low and sodium hydroxide (NaOH) was added. The other reason was evaporation of the water from the membrane bioreactor. Diffusor in the membrane bioreactor could also contributed to that evaporation. Air pressure in the membrane bioreactor could also helped the homogeny mixing and there was no additional mixer in the membrane bioreactor tank. Removal efficiency of the SS, COD, BOD, TN, TP, Ca+2, Mg+2, Na+, CI- and total coliform were 99.97%, 98%, 98%, 60%, 40%, 2.4%, 3.4%, 0.55%, 67% and 100% respectively for the no sludge returning mode. Removal efficiency of the SS, COD, BOD, TN and TP were 99.98%, 99.28%, 98.3%, 66% and 60% respectively for the sludge returning mode. Calcium (Ca+2), magnesium (Mg+2), sodium (Na+) and chlorine (CI-) concentrations were not measured for the sludge returning mode because removal of them was not related with the operation mode. In addition, removal of them were so low that it could be neglected. According to the results there was better removal efficiency when sludge was returned to the feed tank. When sludge was return to the feed tank, there was better phosphorus and nitrogen removal. There was no oxygen in the feed tank, so anoxic process could be more efficient that way. There was % 100 removal of the total coliform and that meant ultrafiltration membrane removed them very efficiently. Calcium (Ca+2), magnesium (Mg+2), sodium (Na+) and chlorine (CI-) removals were so low that it could be negligible. Ultrafiltration membrane could not remove monovalent and multivalent ions efficiently. They also effected the electrical conductivity value of the effluent water which was important for irrigation water. Turbidity values also measured only in the effluent water for both operating modes. It was 0.66 FAU when sludge was not returned and 0.45 FAU when sludge was returned. Effluent water from the membrane bioreactor can be used for the purposes of irrigation (parks, gardens, play grounds, golf courses). In addition they can be used for fire water, flushing water, fire reserve storages and car washing. Irrigation water must be analysed carefully for the toxic compounds that can be found in the effluent water. Heavy metals and other toxic compounds can be found either in very low concentrations in the domestic wastewater or they can not be found at all. When there is a discharge of the industrial wastewaters to the domestic wastewater systems, toxic compounds can be exist in the wastewater, so if there was a plan to reuse the effluent water industrial wastewaters should not be discharged into the domestic wastewater canals. Turkish Wastewater Treatment Plants Technical Aspects Bulletin (2010) has some criteria for wastewater reuse in irrigation. According to the bulletin there are two main class (A and B) for the irrigation. Class A is for landscape and non-commercial plant irrigation. BOD, pH, turbidity, fecal coliform and residual chlorine must be < 20 mg/L, 6-9, < 2 NTU, 0/100 ml and > 1 mg/L respectively. Class B is irrigation for commercially processed plants, restricted areas and non-eatable plants. Class B criteria were, BOD, pH, SS, fecal coliform and residual chlorine must be < 30 mg/L, 6-9, < 30 mg/L, < 200/100 ml and > 1 mg/L. Fecal coliform criteria is lower for Class A because in landscapes people can contact with the bacteria and viruses that can be found in domestic wastewater. Most important criteria for reuse of treated domestic wastewater is microbiological criteria., Yüksek Lisans, M.Sc.

Pharmaceuticals removal from urban wastewater by coupling conventional sand filtration with graphene adsorption reactor (GAR) was investigated. During GAR regime phase, the percentage removal of the four investigated pharmaceuticals, (namely caffeine, carbamazepine, ibuprofen and diclofenac) was higher than 95% (98.2, 97.0, 95.5 and 97.0%, respectively). In spite of the high initial concentrations of the target pharmaceuticals (10 mg/L each) and 4 months of experimentation (62 days of adsorption treatment), typical breakthrough adsorption curves were not observed. Graphene adsorption treatment effectively decreased toxicity to Daphnia magna (0–50% immobilization), but only a slight improvement in germination index (phyto-toxicity tests) was observed after GAR treatment. Finally, graphene performances were compared with conventional (granular activated carbon) adsorption process, and the best performance in the removal of pharmaceutical mixture was quite poor (62% in terms of UV absorbance) compared to GAR (96%).

This work presents a novel integrated process for the reclamation of wastewaters. This process combines, in the same cell, the reduction in the effluent conductivity and TOC by electrodialysis together with the production of a value added stream, which can be used for disinfection purposes. In the diluate compartment, the solution is desalted whereas hypochlorite is electrochemically synthesized in the anolyte. The treatment of actual effluents from the Waste Water Treatment Plant (WWTP) of Ciudad Real (Spain) was confronted. It was observed that the concentration of hypochlorite synthesized in the anolyte increased when anolyte and catholyte are separated into different circuits, avoiding the reduction of hypochlorite on the cathode surface. Furthermore, a higher voltage to cell pair ratio also enhances the production of hypochlorite. Finally, it was checked the disinfectant potential of the final anolyte, being possible to produce a desalted and disinfected final stream with a total electrical consumption of 1.03 W h dm−3 and dosing a volumetric ratio anolyte:diluate of 4:96.

In the last years the water reuse topic has become even more prominent, increasing the need for new practices in terms of efficient water management. Reuse and valorization of water from wastewater treatment plants (WWTPs) can help solving the problem. In this contest, we studied the traditional denitrification/nitrification scheme followed by a natural disinfection/storage tank in order to optimize the process for irrigation reuse. The study is based on data from an experimental pilot-scale plant, located in Trebbo di Reno (BO,Italy) and from a recent field campaign carried out on internal fresh water of the Allacciamento Channel inside the basin of Porto Canale Cesenatico (FC,Italy). Using WEST software to model the first phase and a dispersed flow equation to model the Escherichia coli (E.coli) removal rate in the following tank, we optimize the overall process to test the capacity of a Business Process Management (BPM) approach to model the water storage management for irrigation reuse.

In order to evaluate the feasibility of installing decentralised installations for wastewater reuse in cities, information about flows at specific spots of a sewer is needed. However, measuring intermittent flows in partially filled conduits is a technical task which is sometimes difficult to accomplish. This paper describes a method to model intermittent discharges in small sewers by linking a stochastic model for wastewater discharge to a hydraulic model to predict the attenuation of the discharges and its impact on the arrival time to a defined spot. The method was validated in a case study. The model estimated adequately the wastewater discharges on working days.

In the present work, an integrated pilot-scale membrane system (membrane bioreactor–nanofiltration [MBR–NF]) was applied to the treatment of municipal wastewater to produce reclaimed water. Its performance was evaluated and designed to meet the requirements of the water quality to use in the tanning process. The feasibility of using reclaimed wastewater in the different wet phases of the tanning process (beamhouse, tanning, re-tanning, dyeing, and fatliquoring) was investigated on a pilot scale for manufacturing chrome-tanned leathers. The results showed that the combination of MBR and NF processes applied to municipal wastewaters was adequate for recovering water with low hardness, very low Fe, Mn, and ammonium levels as required by tanneries. The pilot-scale tanning tests demonstrated that there were no significant differences between the wet-blue (chrome-tanned) leathers produced using treated wastewater and those produced using softened tap water in terms of physical and sensorial properties. ...

The boundary flux theory was used to modelize the performance of a nanofiltration (NF) membrane in the treatment of the effluents exiting a two-phase olive oil extraction process, in particular olive mill (OMW) and olives washing (OWW) wastewater streams. The results obtained from the pressure-cycling experiments exhibit a boundary flux pattern with very low long-term fouling for all analyzed feedstocks. This observation is confirmed by the low values of the sub-boundary fouling parameter ( α ) obtained by the fitting of the experimental flux data measured during batch-run operation to the boundary flux model. Reduced long-term fouling (28.6–33.3%) occurred during NF operation of the effluents after the proposed secondary treatment, which comprised pH-temperature flocculation followed by ultraviolet (UV) photocatalysis with ferromagnetic-core nanocatalyst and an ultrafiltration separation step (UF). Otherwise, a decrease of long-term fouling in the range of 57.1–60% was observed by using the secondary-treated 1:1 (v/v) mixture of OMW and OWW as feedstock. Moreover, processing both feedstocks to the complete secondary treatment led to increased feed recovery rates (85–90%) and boundary flux values (12.3–19.6 L h −1 m −2 ). Finally, the standard limits to reuse the purified effluents for irrigation were successfully achieved.

M.Sc. (Chemistry) Volatile fatty acids (VFAs) play a pivotal in the process of nutrient removal by biological processes particularly the enhanced biological nutrient removal process with a side-stream elutriation process using activated sludge. These acids are said to act as intermediates which provide feed for the organisms in a biological phosphorus and nitrogen removal (BNPR) system, such as phosphorus-accumulating organisms (PAOs) and nitrate-accumulating bacteria (NABs). In wastewater treatment plants, VFAs play a vital role as intermediate organic compounds during the fermentation processes which generate methane gas and when present at elevated levels they are known to cause microbial stress, acidification as well as the poor performance of anaerobic digesters. For these reasons, the routine monitoring of VFA levels in wastewater treatment plants is crucial as they will act as indicators of the efficiency and optimal operation performance of the anaerobic digesters. Normally the VFAs that are commonly produced during the anaerobic fermentation process include acetic acid, propionic acid, butyric acid, and valeric acid and of these, acetic and propionic acids form the major VFAs that are generated, thus the yields of these two compounds provide a useful measure of the anaerobic digester performance. For example, the ratio of propionic acid to acetic acid is always used as an indicator of digester imbalance while high concentrations of acetic acid (e.g. > 800 mg/ℓ) or a propionic acid to acetic acid ratio greater than 1.4 is an indication of digester failure. This study was thus aimed at establishing the complete VFA profile at the Johannesburg Water (JW) Northern Works Wastewater Treatment Plant in Johannesburg, South Africa, by developing analytical methods to quantify the VFAs in the wastewater treatment plant. In addition, the level of VFAs quantified was used to evaluate the efficiency of the fermentation treatment process in wastewater treatment systems in order to give an indication of the bacterial activities in the systems; to determine the ratios of the VFAs, especially the propionic acid to acetic acid ratio, to establish the performance and efficiency of various wastewater treatment plants; and to determine whether there is any imbalance in the anaerobic digesters. Two analytical methods for the determination of VFAs were successfully developed and applied to real wastewater samples. The first method developed was a liquid-liquid extraction method using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS. The method involved two extracting solvents, namely dichloromethane (DCM) and methyl-tert-butyl ether (MTBE). The extraction capacity of these two solvents was compared. The second method successfully developed and optimised headspace-solid phase microextraction (HS-SPME) using GC-TOF-MS. The microextraction fibre used was a polydimethylsiloxane (PDMS) fibre. Studies to validate the developed methods were also carried out by calculating the limit of detection (LOD) and limit of quantification (LOQ). Ratios of propionic acid to acetic acids were determined as well as the concentrations of acetic acid for both developed methods in order to evaluate the performance and efficiency of the treatment process. The results of the study show that the extraction procedure using solvents DCM and MTBE showed that exhaustive extraction was achieved by MTBE. Higher concentrations of acetic acid and propionic acid were obtained by MTBE. The overall fermentation performance for all three units in the period when the samples were collected, which was measured by the ratio of propionic to acetic acid was good since the ratio did not exceed 1.4. The acetic acid concentration in mg/ℓ was < 800 mg/ℓ for all units thus it can be said that the reactor balance was maintained for the period studied. The method LOD ranged from 0.034 mg/ℓ to 0.21 mg/ℓ and the method LOQ ranged from 0.11 mg/ℓ to 0.70 mg/ℓ. Optimisation of extraction parameters was achieved for headspace solid-phase microextraction using the PDMS fibre method. The extraction method was conducted for 60 min using a sample volume of 4 mℓ and the amount of sodium salt added was 1.50 g. The desorption temperature and time was 210ºC and 5 min, respectively. The LOD values ranged from 0.079 to 2.07. The PDMS fibre was found to be suitable for extracting higher carbon chain fatty acids as compared to lower carbon chain fatty acids. The plant performance for the period studied was on par as indicated by ratios of propionic acid to acetic acid which all fell below 1.4. There were no digester failures for the period studied. The acetic acid concentration in mg/ℓ was < 800 mg/ℓ for all 3 units.

Thirty strains of microfungi and amylolytic yeasts were screened for production of microbial biomass protein (MBP) and water reclamation from starch processing wastewater (SPW). Three species and six strains of microfungi Aspergillus oryzae, Rhizopus oligosporus and Rhizopus arrhizus showing high enzymatic activities on SWP were selected under non-aseptic growth conditions. In 20 h submerged cultivation the selected strains had a high capacity to enzymatically hydrolyse more than 93% of the starch and produce 4.3–5.6 g dm−3 of dry biomass at a specific biomass growth rate from 0.05 to 0.12 h −2. The fungal biomass contained crude protein ranging from 37.5 to 49.8% of dry biomass. The pellet and flocculated biomass products were easily harvested by simple filtration or sedimentation. After these processes, 76–88% of total organic carbon (TOC), 85%–92% of chemical oxygen demand (COD) and 95% suspended solids in SPW were removed, and the treated water was reusable for farm irrigation. Typical pretreatment processes including hydrolysis, sterilisation and nutrient supplementation were unnecessary. © 1999 Society of Chemical Industry

A secondary treatment for olive mill wastewater coming from factories working with the two-phase olive oil production process (OMW-2) has been set-up on an industrial scale in an olive oil mill in the premises of Jaen (Spain). The secondary treatment comprises Fenton-like oxidation followed by flocculation-sedimentation and filtration through olive stones. In this work, performance modelization and preliminary cost analysis of a final reverse osmosis (RO) process was examined on pilot scale for ulterior purification of OMW-2 with the goal of closing the loop of the industrial production process. Reduction of concentration polarization on the RO membrane equal to 26.3% was provided upon increment of the turbulence over the membrane to values of Reynolds number equal to 2.6 × 104. Medium operating pressure (25 bar) should be chosen to achieve significant steady state permeate flux (21.1 L h−1 m−2) and minimize membrane fouling, ensuring less than 14.7% flux drop and up to 90% feed recovery. Under these conditions, irreversible fouling below 0.08 L h−2 m−2 bar−1 helped increase the longevity of the membrane and reduce the costs of the treatment. For 10 m3 day−1 OMW-2 on average, 47.4 m2 required membrane area and 0.87 € m−3 total costs for the RO process were estimated.

The report uses a theoretical model of a typical drainage basin, but the approach could be applied to many of the drainage basins managed by the holding company for water and wastewater in Egypt. This study set out to assess the relative health impacts of different wastewater management strategies on health in the Nile delta region using an approach similar to that used in the Ghana. The ultimate objective was to develop a framework for long-term investment planning based on monitoring of health and productivity impacts of proposed Bank operations which could be included in project Monitoring and Evaluation (M&E) systems. This will equip task teams to assess the risks and opportunities which arise due to the proposed shift from on-site to networked sanitation in four governorates where the Bank has wastewater operations. A secondary objective was to assess the extent to which existing legislation supports health riskbased planning. The conclusions of the study provide an indication of how such methods could increasingly be used to enable the selection of cost-effective and appropriate wastewater management strategies.

Water is a scarce resource in Israel. With fluctuating supplies and an increasing demand, the need for using alternative water sources such as reclaimed wastewater, brackish groundwater and desalinated seawater increases. This paper investigates the economy-wide effects of a de-clining supply of natural fresh water (ground and surface water) and the increasing utilization of alternative water sources (recycled wastewater, brackish water, desalinated seawater). To ac-count for different production structures and usage options, a single country Computable Gen-eral Equilibrium (CGE) model is used, in which several water activities produce differentiated water commodities. These water commodities are used as intermediate inputs in other produc-tion activities or are consumed by households. Results suggest that especially the agricultural sector would be affected by a reduction of natu-ral fresh water availability, as it is the largest water user. However, the effect can be mitigated if substitution possibilities with alternative water sources are increased, especially the desalination of seawater can contribute to this. The rest of the economy is affected to a lesser extent, as water is only a minor input in other sectors and the water sector itself is small compared to the whole Israeli economy.

Zugleich gedruckt erschienen im Universitätsverlag der TU Berlin unter der ISBN 978-3-7983-2268-4., Die MENA (Mittlerer Osten und Nordafrika) ist das trockenste Gebiet der Welt. Die nutzbaren Wasserressourcen gehen zurück, während die Nachfrage - auf Grund eines raschen Bevölkerungswachstums – steigt. Bewässerte Ackerflächen verbrauchen die größte Menge der Wasserressourcen als ein Ergebnis fortwährender Nachfrage für die Nahrungsproduktion. Ein großes Potential diese steigende Nachfrage zu befriedigen, besteht darin, kommunales Abwasser in der Landwirtschaft wiederzuverwenden. Die Wiederverwendung aufbereiteten Abwassers in der Landwirtschaft führt zu zusätzlichen Wassermengen für die Bewässerung and gibt gleichzeitig Frischwasser frei, das wieder in den öffentlichen Wassersektor eingeleitet werden kann, wo höhere Wasserqualität benötigt wird. Zur Zeit wird in einigen MENA Ländern bereits aufbereitetes Abwasser genutzt. Trotzdem sind diese Mengen im Vergleich zu aufbereiteten Abwässern noch sehr gering. Die wichtigste These dieser Dissertation besteht darin, anzunehmen, dass die Ausweitung des Konflikts über Frischwasser zwischen den verschiedenen Wassersektoren zu vermehrter Wiederverwendung von Abwasser in der Landwirtschaft führen kann. Darüber hinaus hat die mangelnde Wiederverwendung von Abwasser weniger mit teuren Behandlungskosten als viel mehr mit dem Fehlen von geeigneten Wasserpolitiken und angemessenen institutionellen Rahmenbedingungen zu tun. Die Zielsetzung dieser Dissertation ist die Analyse von Politiken, rechtlichen und institutionellen Rahmenbedingungen sowie die Komponenten der Wiederverwendung von Abwasser in der Landwirtschaft. Ein systematischer Ansatz wurde gewählt, um die existierenden organisatorischen Strukturen sowie die Rollen und Verantwortlichkeiten der unterschiedlichen Akteure bei der Wiederverwendung von Abwasser zu identifizieren. Die Analyse wird durch die Fallstudie „Jordanien“ vertieft. Als Grundlage dient in dieser Dissertation die ausführliche Durchsicht der zugänglichen Literatur, die Richtliniendokumente und Gesetze über die Wiederverwendung von Abwasser in Jordanien., The MENA (Middle East and North Africa) region is the driest in the world. Water resources are deteriorating while demand for water is increasing due to the rapid population growth. Irrigated agriculture consumes the largest volume of water resources as a result of continuous demand for food production. A huge potential for satisfying this increasing demand exists in the reuse of municipal wastewater in agriculture. The reuse of treated wastewater in agriculture will provide supplement water quantities for irrigation and will free amounts of freshwater to be reallocated within the municipal water sector, where higher water quality is required. Currently, some wastewater quantities in the MENA countries are already reused. However, the amounts of wastewater reused in comparison to collected and treated wastewater are still low. The main assumptions of this dissertation are that the extent of conflict over freshwater resources between the different water sectors can foster wastewater reuse in agriculture. In addition, the insufficiency associated with wastewater reuse has less to do with the expensive treatment processes rather than with the lack of appropriate water policies and the enabling institutional setting. The dissertation’s main objective is the analysis of policies, legal and institutional settings and the components of wastewater reuse in agriculture. A systematic approach was used to identify existing organizational structures; roles and responsibilities of different actors involved in wastewater reuse. The in-depth-analysis is presented through the case study of Jordan. For evidence, the dissertation focuses on an extensive review of the literature available and policy documents and laws on wastewater reuse in Jordan.

Rainfall diminution in the last years has entailed water scarcity in plenty of European regions, especially in Mediterranean areas. As a consequence, regional water authorities have enhanced wastewater reclamation and reuse. Thus, the implementation of tertiary treatments has become of paramount importance in the municipal wastewater treatment plants (WWTP) of Valencian Region (Spain). Conventional tertiary treatments consist of a physico-chemical treatment of the secondary effluent followed by sand filtration and UV radiation. However, the addition of coagulants and flocculants sometimes does not contribute significantly in the final water quality. In this work, results of 20-months operation of three WWTP in Valencian Region with different tertiary treatments (two without chemicals addition and another with chemicals addition) are discussed. Besides, experiments with a 2 m3/h pilot plant located in the WWTP Quart-Benager in Valencia were performed in order to evaluate with the same secondary effluent the effect of the chemicals addition on the final water quality. Results showed that the addition of chemicals did not improve the final water quality significantly. These results were observed both comparing the three full scale plants and in the pilot plant operation.

[EN] The use of large quantities of sulfuric acid and other sulfur-containing chemicals causes high sulfate concentrations in the wastewater of a tannery. The aim of this work was reducing the sulfate concentration in the final wastewater from a tannery. For that, firstly a study about the main sulfate sources in a tannery was carried out and the total sulfates load in the tannery wastewater was evaluated. Two measures for sulfates reduction were studied: the recycling of unhairing wastewater to the soaking drums and the reuse of the chromium sulfate from the tanning washing wastewater after its separation by nanofiltration (NF). The first measure proposed was studied experimentally in laboratory drums of 5 L of volume. Two series of experiments with different volumes of unhairing wastewater in the soaking bath were carried out. The quality of the final leather was evaluated by means of mechanical tests. NF experiments were carried out in a laboratory pilot plant with a spiral wounded membrane element. Concerning the results, the combination of 50% unhairing wastewater and 50% of fresh water was appropriate in order to obtain leather with an acceptable quality. Besides, it drove to a diminution of approximately 10% in the addition of sulfide in the unhairing. Related to the NF experiments, 97% of the sulfates were rejected by the membrane. The separated ions could be recycled to the tanning drums. The application of the two measures (firstly the recycling of the unhairing wastewater and secondly the NF of the tanning washing wastewater) drove to a reduction of 14.82 kg SO 4 -2 t -1 of raw hide. © 2010 Elsevier Ltd. All rights reserved.

cited By 6; International audience; Phosphorus (P) removal in constructed wetlands (CWs) has received particular attention during the last decades by using specific materials which promote P adsorption/precipitation phenomena. Recent studies have shown an interest in using apatite materials to promote P precipitation onto their surface. About ten years of experiments at different scales (laboratory, pilot, full scale) have passed. The process is now open in France. This paper presents the first design recommendations according to the apatite mineral quality and treatment outlet requirements. Kinetics and their evolution with the material saturation degree are presented based on the k-C* model. The process can achieve 1 mgP.l-1 for long term while using surface P removal filter area of 0.5 m2.p.e.-1. With a low land footprint and high P removal efficiency, the interest of the process also result in the orthophosphates accumulation on a phosphate mineral which makes easier to reuse phosphorus from wastewater once saturated. © IWA Publishing 2011.

In this study, two of our recently developed laboratory scale wastewater treatment systems, fluidized-bed reactor (FBR) using formulated clay mixture absorbents (clay-FBR adsorption) and an annular slurry photoreactor (ASP) using TiO(2) impregnated kaolin catalysts (TiO(2)-K-ASP) were integrated as an adsorption-photocatalysis hybrid process to treat municipal wastewater as alternative secondary and tertiary treatment for wastewater reclamation. Primary effluent from sewage and secondary effluent from a membrane bioreactor treatment process were used to assess chemical removal capabilities of the FBR and ASP systems, and the hybrid process. The formulated clays-FBR system demonstrated the prevailing removal efficiency toward PO(4)(3-), NO(3)(-) and suspended solids. The TiO(2)-K-ASP showed superior degradation of dissolved organic content; while the presence of inorganic ions caused a detrimental effect on its performance. The integration of the adsorption and degradation system as a hybrid treatment process resulted in a synergetic enhancement for the chemical removal efficiency. Complete elimination of PO(4)(3-) content was obtained in the adsorption stage; while 30% and 65% NO(3)(-) removal were obtained from the hybrid treatment of the primary and secondary effluents, respectively. The corresponding COD reduction during the photodegradation was further investigated by the high-performance size exclusion chromatography technique, where it revealed the shift of apparent molecular weight of the dissolved organic contaminants toward the smaller region. This present study demonstrated that this adsorption-photocatalysis hybrid technology can be used as a feasible alternative treatment process for wastewater reclamation.

Adsorption processes have long been used in water and wastewater treatment and a deterministic approach has been often adopted for the analysis of fundamental mechanisms. In this research, a new approach based on statistical treatment of modelling data is adopted for the analysis of trichloroethylene (TCE) adsorption on granular activated carbon (GAC) from synthetic groundwater. The work starts from an experimental analysis aimed at the assessment of the influence of thermodynamic parameters (concentration, pH, salinity, temperature and the presence of an organic non-ionic compound, i.e. ethyl acetate) on TCE adsorption capacity. A wide range of process parameters have been considered to simulate highly polluted groundwater, as when leachate infiltrations occur at solid waste landfill. Experimental results show that adsorption capacity decreases by increasing the temperature and the ethyl acetate concentration, while neither pH nor salinity have any influence. A thorough understanding of adsorption mechanism and the individuation of the model with highest physical and mathematical significance is carried out by a thermodynamic analysis and a statistical methodology based on Analysis of Variance (ANOVA). The latter indicates that in dilute solutions the Freundlich model is the best data fitting model for TCE adsorption, among those which are commonly adopted.

In this study, nine metals (Al, Cd, Cr. Cu, Fe, Mn, Ni, Pb, and Zn) found in urban wastewater treatment plants (WTPs) in Bursa (Turkey) were monitored for 23 months in 2002 and 2007. Metal influent and effluent concentrations of wastewater stabilization ponds (WSPs) and the activated sludge process (ASP) measured via 24-h composite samples were used to determine removal efficiencies. Average influent concentrations ranged between 2 mu g/L (Cd) and 1975 mu g/L (Fe). In the stabilization ponds, the removal efficiency was 58% for Cr, while for Cd. Mn, and Pb, it was less than 20%. The activated sludge process yielded high removal efficiencies, ranging from 47% for Ni to 95% for Cr. The use of treated wastewaters for agricultural purposes was investigated, and it was determined that all metal concentrations met application limits, with the exception of Cr in wastewater stabilization pond effluent. Results showed that wastewater stabilization pond effluent reduced the receiving water quality with respect to Cr, Cu, Ni. and Pb. In addition, it was shown that effluent from the activated sludge process temporarily improved the receiving water quality with regard to the Cd, Cu, Mn, and Zn parameters. However, considering the periodic variations of the metals in both processes, water quality, and agricultural practices, it was determined that they should be monitored continuously. (C) 2009 Elsevier B.V. All rights reserved. BUSKİ

Sustainability in tourism branch requires a conscious management of environment and natural resources, as tourist resorts cause seasonal peaks of anthropogenic load on their environment.Popular regions for summer holidays are usually arid or semi-arid regions (e.g. Mediterranean zone), feeling the pressure of both irrigation and tourism in the same period. In most cases large tourist resorts experience the problems simultaneously; hence a combined solution should be sought.

Reuse of treated effluent is a highly valued water source in Palestine, however with limited success due to public health concerns. This paper assesses the potential pathogens in raw, treated and reclaimed wastewater at Albireh urban wastewater treatment facility, and provides scientific knowledge to update the Palestinian reuse guidelines. Laboratory analyses of collected samples over a period of 4 months have indicated that the raw wastewater from Albireh city contained high numbers of fecal coliforms and worm eggs while 31% of the samples were Salmonella positive. Treated effluent suitable for restricted irrigation demonstrated that the plant was efficient in removing indicator bacteria, where fecal coliforms and fecal streptococci removal averaged 99.64% and 93.44%, respectively. Although not disinfected, treated effluent was free of Salmonella and parasites, hence safe for restricted agricultural purposes. All samples of the reclaimed effluent and three samples of irrigated grass were devoid of microbial pathogens indicating a safe use in unrestricted agricultural utilization. Adequate operation of wastewater treatment facilities, scientific updating of reuse guidelines and launching public awareness campaigns are core factors for successful and sustainable large-scale wastewater reuse schemes in Palestine.

Subsurface water reclamation systems (SWRS) in mountain watersheds commonly experience issues of water sustainability, and are generally designed through judgment and experience rather than through rigorous quantitative methods. I have made a detailed vadose-zone characterization of several saturated and unsaturated flow parameters in an excavated trench representative of the size of a typical domestic drainage field at a wastewater reclamation test site (WRTS) at Mines Park, Golden, CO with the objective to improve the pre-design techniques associated with SWRS. Most wastewater infiltration is an unsaturated water flow process; therefore, measurement of soil-hydraulic parameters, especially saturated and unsaturated hydraulic conductivity (Ksat and Kunsat), is required. Toward this end, I compared the consistency of estimating or measuring Ksat and Kunsat through field, laboratory, and empirical methods. Field data collection included Guelph Permeameter and Tension-disc Infiltrometer measurements in the excavated trench, and Slug Test measurements at nearby monitoring wells. Representative soil samples were collected for in-lab experimentation at the UT Bureau of Economic Geology, including the van Genuchten-Mualem transformations of capillary-pressure curves determined from hanging-column measurements. Additional estimates of Ksat and Kunsat were determined through nine empirical functions and the Rosetta neural network found within Hydrus-1D software. Spatial variations in Ksat and Kunsat determined from the various methods are illustrated by curves that plot Ksat or Kunsat according to location. Statistical analyses demonstrate such a large degree of spatial variability that no single measurement adequately represents the values of these parameters, whether along the excavated trench or between the upper and lower tiers of the trench. The following main conclusions are offered: (1) spatial variations in Ksat and Kunsat occur along a trench and with depth, in which Kunsat exhibits much larger variability with depth than does Ksat; (2) of the empirical functions, results of the Hazen (1893), Harleman et al. (1963), and Beyer (1964) methods compare most favorably to both field methods (Guelph Permeameter, Tension-disc Infiltrometer), providing data that agree with the field-measured values within a factor of two; (3) the Guelph Permeameter field method is the least time consuming and less complicated, but the most arduous to conduct of all field methods; (4) Rosetta estimates with either sand/silt/clay input or soil classification input data provide Kunsat values most similar to the Hanging Column values using the van Genuchten-Mualem relationship; and (5) a single measurement did not appear to represent the hydraulic properties of an entire area occupied by a typical wastewater infiltration trench. I found variation both horizontally along the length of each tier and vertically between Tier 1 (2 feet below ground surface) and Tier 2 (4 feet bgs). This research advances the use of rigorous quantitative measurements and methods in understanding the design of SWRS

Wastewater reuse presents a promising solution to the growing pressure on water resources. However, wastewater reuse implementation faces obstacles that include insufficient public acceptance, technical, economic and hygienic risks and further uncertainties caused by a lack of awareness, accepted standards, uniform guidelines and legislation. So far, there are no supra-national regulations on water reuse in Europe and further development is slowed by lack of widely accepted standards, e.g. in terms of required water quality, treatment technology and distribution system design and operation. Treatment technology encompasses a vast number of options and membrane processes are regarded as key elements of advanced wastewater reclamation and reuse schemes and are included in a number of prominent schemes world-wide, e.g. for artificial groundwater recharge, indirect potable reuse as well as for industrial process water production. For dual reticulation purposes in urban areas two types of systems have been built, a centralised type of treatment with dual membrane processes, including e.g. microfiltration (MF) and reverse osmosis (RO), and small scale systems using membrane bioreactors. This paper will provide an overview of the status of membranes processes in wastewater reclamation and reuse world-wide and will depict their potential role in promoting more sustainable water use patterns.