Article

Wastewater recycling in laundries—From pilot to large-scale plant

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Abstract

A new, innovative wastewater recycling process for industrial laundries has been developed through cooperation between Textil-Service Klingelmeyer (a medium-size laundry in Darmstadt, Germany) and the University of Applied Sciences in Karlsruhe, Germany. The project “Laundry Innovative Wastewater Recycling Technology—LIWATEC” was sponsored by the European Community in its LIFE-Environment programme. The purpose of the LIWATEC project was to design and start up a new, innovative, integrated process using membrane technology for wastewater reuse on a large scale in the Klingelmeyer laundry. The large scale plant was designed for wastewater treatment capacity of 200 m3/day. This integrated process has been successfully tested for 5 years in the form of two pilot plants at the laundry in Darmstadt and at the University of Karlsruhe (capacities: 10 m3/day and <1 m3/day). The pilot plant data provided a scale up basis for designing the large plant. This paper gives a summary of the pilot plant data in comparison with the initial results of the large-scale unit, which went into operation in June 2006. The integrated process comprises a membrane bioreactor (MBR) with submerged plate and frame microfiltration membranes as the principal cleaning unit. The results of the pilot agree with those of the large-scale plant. The chemical oxygen demand (COD) removal efficiency was around 90%; the average flux was approximately 14 L/m2 h. The MBR permeate provides a water quality that can be used as washing water since it fully meets the requirements of the washing process. Part of the MBR permeate is subsequently treated by reverse osmosis (RO) filtration using spiral wound modules in order to remove salts. The average flux of the RO unit is 25–30 L/m2 h at around 16 bar. The salt retention rate exceeds 99%. The high quality of the reverse osmosis permeate meets the demands of the rinsing processes. In general, up to 90% of total wastewater can be reused. Moreover, it is an easy-handling and cost-efficient wastewater recycling process that could be adapted to different types of laundries due to its modular structure.

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... Since nutrient concentrations in the laundry effluent were very low (0.7 mg/l TN, < 0.03 mg/l TP), comparison of removal rates is likely not expressive. Other studies report values from 2.8 to 40 mg/l for TN and 0.2 to 51.6 mg/l for TP [13,17,18,23]. The pH of 6.9 was almost neutral. ...
... The COD concentration (318 mg/l) was in the same range of studies with lightly polluted laundry effluent (Table 6) [26,32]. However, most studies report higher COD values between 582 and 1700 mg/l (Table 6) [19,20,23,24,31,44]. The same pattern can be seen for TOC and turbidity. ...
... The average concentration for COD in the treated water was 28 mg/l. This value was always below defined limit values for laundry water from literature (50 mg/l [3], 100 mg/l [31], 150 mg/l [23]) but showed an increase over time. In addition, water losses were rather high (31%), meaning the same amount was refilled with tap rainwater, resulting in dilution of pollutant concentrations and lower values in the treated water. ...
Article
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In the scope of this study, a pilot facility for the recycling of laundry effluent was developed and tested. With the aim to enable nearly complete energy and water self-sufficiency, the system is powered by a photovoltaic plant with second-life batteries, treats the wastewater within the unit and constantly reuses the treated wastewater for washing in a closed cycle. The technology for wastewater treatment is based on a low-tech approach consisting of a physical/mechanical pre-treatment and biological treatment in trickling filter columns. The treatment process is operated in batch mode for a capacity of five washing cycles per day. During five weeks of operation water quality, energy consumption and production, water losses and washing performance were monitored. The system recovered 69% of the used water for the washing machine while treating the wastewater to the necessary water quality levels. The average COD removal rate per cycle was 92%. Energy analysis was based on modelled data of the monitored energy consumption. With the current set-up, an internal consumption rate of 80% and self-sufficiency of 30% were modelled. Future developments aim at increasing water and energy self-sufficiency and optimizing the water treatment efficiency.
... Such a huge amount of wastewater creates a need to develop methods of its reuse during the laundering process. Therefore, not only treatment of the wastewater generated in the industrial laundries but also water recycling are of a special interest (Deowan et al. 2015;Hoinkis and Panten 2008;Marcucci et al. 2002). The treatment of laundry wastewater is difficult since it contains high concentrations of contaminants such as fats, oils, suspended solids, surfactants, and a high microbial load. ...
... Taking into consideration the low efficiency of the simple treatment systems, the more advanced configurations were proposed. One approach is application of membrane bioreactors (MBRs) (Hoinkis and Panten 2008;Hoinkis et al. 2012). Hoinkis et al. (2012) pointed out that when only low or medium water quality is required, the MBR effluent can be directly reused as process water (e.g., for washing purposes). ...
... However, in the case of more stringent requirements concerning the recycled water quality, an additional posttreatment, using, e.g., nanofiltration (NF) or reverse osmosis (RO) is needed. Such a system composed of the MBR unit equipped with MF membranes and RO posttreatment was applied in a commercial laundry in Darmstadt, Germany (Hoinkis and Panten 2008;Hoinkis et al. 2012). In the system, only a part of the MBR permeate was posttreated using RO. ...
Article
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The possibilities of application of a three-step system combining hybrid biological treatment followed by advanced UV/O3 oxidation with in situ generated O3 and membrane separation (ultrafiltration (UF) and nanofiltration (NF)) to treat and reuse the wastewater from an industrial laundry are presented. By the application of a hybrid moving bed biofilm reactor (HMBBR), the total organic carbon concentration was reduced for about 90 %. However, since the HMBBR effluent still contained organic contaminants as well as high concentrations of inorganic ions and exhibited significant turbidity (8.2 NTU), its further treatment before a possible reuse in the laundry was necessary. The UV/O3 pretreatment prior to UF was found to be an efficient method of the membrane fouling alleviation. During UF, the turbidity of wastewater was reduced below 0.3 NTU. To remove the inorganic salts, the UF permeate was further treated during NF. The NF permeate exhibited very low conductivity (27–75 μS/cm) and contained only small amounts of Ca2+ and Mg2+; thus ,it could be reused at any stage of the laundry process.
... The MBR systems can replace conventional treatment and combine clarification, aeration and filtration into a single unit in a simple and cost-effective way that reduces capital and operational costs. Hoinkis and Panten (2008) reported that the result is consistent production, by MBRs, of high quality effluent suitable for any discharge or re-uses. The MBRs systems are increasingly being specified as the best available technology for virtually all wastewater treatment applications-from green field plants to retrofits to water reclamation projects. ...
... They offer several operational and economic advantages over conventional wastewater treatment plants including extremely compact footprints, simplified operation and consistently high quality effluent -all for a satisfactory life cycle cost, describe by Abegglen and Siegrist (2006). In several studies by Hoinkis, and Panten (2008), Abegglen and Siegrist (2006) and Cicek (2002) contented that MBRs system has been tested in the treatment of effluent from food and beverage, chemical, petrochemical, pharmaceutical and cosmetics, and textile industries as well as from laundries, and the treated water quality has been found to meet the required standard with respect to the chemical oxygen demand (COD), biochemical oxygen demand (BOD), suspended solids (SS), and turbidity. ...
... The COD at the ETP-exit, however, more or less follows the fluctuation in the feed values. Similar stabilization of the COD level in the MBR with fluctuation in the feed level was observed also by Hoinkis and Panten (2008) and Huang et al. (2009). ...
Article
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For the first time in Bangladesh, a bench scale membrane bioreactor (MBR) unit was tested in treating a textile wastewater in the industry premises of EOS Textile Mills LTD, Dhaka for three months. The performance of the unit was compared with that of the conventional activated sludge treatment plant, which is in operation in the same premises. The COD and BOD removal efficiency of the MBR unit reached to around 90% and 80% respectively in 20 days whereas the removal efficiency of the conventional treatment plant was as low as 40-50% and 38-40% respectively. The outlet COD and the BOD level for the MBR unit remained stable in spite of the fluctuation in the feed value, while the conventional effluent treatment plant (ETP) failed to keep any stabilized level. The performance of the MBR unit was much superior to that of the functional ETP and the water treated by the MBR system can meet disposal standard.
... One of the significant operating costs of an industrial laundry is water and wastewater management. Because of that, laundry investment plans should take into account an improvement of wastewater treatment and water reuse systems [1,2]. Therefore, research in this field is necessary for the optimal design of water and wastewater management facilities. ...
... Another attempt was based on the utilization of biological technologies such as membrane bioreactors (MBR) [1,[12][13][14], sequencing batch reactors (SBR) [4], or moving bed bioreactors (MBBR) [15][16][17]. MBR and MBBR technologies were found to be effective in the treatment of wastewater containing detergents both when applied as a stand-alone process or as the first stage before laundry water renewal processes [1,[18][19][20]. ...
... Another attempt was based on the utilization of biological technologies such as membrane bioreactors (MBR) [1,[12][13][14], sequencing batch reactors (SBR) [4], or moving bed bioreactors (MBBR) [15][16][17]. MBR and MBBR technologies were found to be effective in the treatment of wastewater containing detergents both when applied as a stand-alone process or as the first stage before laundry water renewal processes [1,[18][19][20]. It was found that the laundry wastewater treated in MBBR met the quality standards required by law for wastewater discharged to surface waters [16,17]. ...
Article
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This paper describes the investigations on the possibilities of treatment of wastewater generated in an industrial laundry with application of a combined biological-photooxidation- membrane system aimed at water recycle and reuse. The two treatment schemes were compared: 1) scheme A consisting of a treatment in a moving bed biological reactor (MBBR) followed by microfiltration (MF) and nanofiltration (NF), and 2) scheme B comprising MBBR followed by oxidation by photolysis enhanced with in situ generated O3 (UV/O3) after which MF and NF were applied. The removal efficiency in MBBR reached 95-97% for the biochemical oxygen demand; 90-93% for the chemical oxygen demand and 89-99% for an anionic and a nonionic surfactants. The application of UV/O3 system allowed to decrease the content of the total organic carbon by 68% after 36 h of operation with a mineralization rate of 0.36 mg/L·h. Due to UV/O3 pretreatment, a significant mitigation of membrane fouling in the case of both MF and NF processes was achieved. The MF permeate flux in the system B was over two times higher compared to that in the system A. Based on the obtained results it was concluded that the laundry wastewater pretreated in the MBBR-UV/O3-MF-NF system could be recycled to any stage of the laundry process.
... MBR technology is a combination of the conventional biological sludge process, combined with a microfiltration (MF) or ultrafiltration (UF) membrane system [2]. For treatment of laundry wastewater containing surfactants, both aerobic [3][4][5][6][7][8] and anaerobic [9] membrane reactors were used. Nicolaidis and Vyrides [3] achieved 99% efficiency in the removal of turbidity as well as total solids and 70%-99% efficiency in the removal of chemical oxygen demand (COD) in a full-scale submerged aerobic MBR (9 m 3 ) used for laundry wastewater treatment [3]. ...
... The average COD and total organic carbon removal efficiency in the MBR reactor with immersed Kubota membranes was higher than 90%. Part of the MBR permeate is subsequently treated using reverse osmosis filtration [4,5]. In another research study, a submerged MBR with a cross-flow MF membrane (pore nominal diameter of 0.4 μm) was used. ...
... The frequency of chemical cleaning depends on the feed pretreatment processes used, and these are mainly concerned with the removal of suspended solids. Hoinkis and Panten [4] and Hoinkis et al. [5] used sieve and screen with a mesh size of 200 μm while Nicolaidis and Vyrides [3] used parabolic fine screen mesh of size 1.0 mm [3]. Sieving followed by coagulation-flocculation and clarification were used by Lubello et al. [8]. ...
Article
This research carried out membrane bioreactor (MBR) pilot plant tests on the treatment of industrial laundry wastewater as well as making an analysis of MBR pilot plant operational conditions. The experiments were carried out in-place at the large-scale industrial laundry in Poland with usage of real wastewater. The MBR pilot plant used worked under aerobic conditions. The laundry wastewater, containing mainly surfactants and impurities originating from washed fabrics, was supplemented with a solution of urea to increase nitrogen content and a solution of acid to adjust pH. Daily flow of raw wastewater was equal to 0.25–0.5 m³/d and hourly flow was equal to 13–25 L/h. The removal efficiency of organic pollutants, determined as 5-d biochemical oxygen demand and chemical oxygen demand, amounted to 95%–98% and 89%–94%, respectively; whereas in the case of other parameters, it was 32%–84% for total N, 55%–71% for total P, 94.5%–99.5% for anionic surfactants, and 98.8%–99.4% for nonionic surfactants. The quality of the purified wastewater meets the legal requirements regarding the standards for wastewater discharged to the environment. However, due to the hydraulic instability and short failure-free periods of membrane operation, the investigated system needs further optimization to be used for industrial laundry wastewater treatment plant.
... Membrane bioreactors (MBR), moving bed bioreactors (MBBR) as well as sequencing batch reactors (SBR) have been used for aerobic laundry wastewater treatment. Pilot MBR plants with microfiltration membranes reduce the COD of raw laundry wastewater by approximately 90% ( Hoinkis and Panten, 2008). Part of the MBR permeate was subsequently treated by reverse osmosis (RO) filtration ( Hoinkis and Panten, 2008). ...
... Pilot MBR plants with microfiltration membranes reduce the COD of raw laundry wastewater by approximately 90% ( Hoinkis and Panten, 2008). Part of the MBR permeate was subsequently treated by reverse osmosis (RO) filtration ( Hoinkis and Panten, 2008). Results of MBBR tests showed that the BOD could be reduced to 12.7 mg/L and the TOC to 6.8 mg/L ( Altenbaher et al., 2010). ...
Article
Large, laboratory scale biological treatment tests of real industrial wastewater, generated in a large industrial laundry facility, was conducted from October 2014 to January 2015. This research sought to develop laundry wastewater treatment technology which included tests of a two-stage Moving Bed Bio Reactor (MBBR); this had two reactors, was filled with carriers Kaldnes K5 (specific area - 800 m2/m3) and were realized in aerobic condition. Operating on site, in the laundry, reactors were fed actual wastewater from the laundry retention tank. The laundry wastewater contained mainly surfactants and impurities originating from washed fabrics; a solution of urea to supplement nitrogen content and a solution of acid to correct pH were added. The daily flow of raw wastewater Qd varied from 0.6-1.0 m3/d. Wastewater quality indicators showed that the reduction of pollutants was obtained: BOD5by 95-98%, COD by 89-94%, the sum of anionic and nonionic surfactants by 85-96%. The quality of the purified wastewater after the start-up period met legal requirements regarding the standards for wastewater discharged into the environment.
... However, the current industrial laundries are not capable of removing MNPs on site. An estimated 90% of industrial laundry wastewater discharges to sewage without adequate treatment, contributing to MNPs load in WWTP inlet water [4]. ...
... These numbers pose new issues for the regulation of biosolid disposal in the environment. The washing processes of synthetic textiles have been assessed as the main source of MPs [6][7][8], that enter the oceans [1,[3][4][5]. Even if up to 99% of MPs are removed by wastewater treatment plants [9], some, especially the fiber-shaped ones, are released with the effluent [2,10,11] and can pose a threat to ecosystems and human health [3]. ...
Article
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This study compares the performance of a microfiltration membrane, made by silicon carbide (SiC) and an ultrafiltration membrane, made by zirconia (ZrO2), in the treatment of wastewater from a washing machine designed to clean industrial tents. The filtration of deionized water, containing model microplastics (i.e., nylon fiber), was performed. This was followed by the filtration of real wastewater from a single washing cycle of industrial tents, made from polyvinyl chloride (PVC) textile. The filtration parameters of the membranes and physical-chemical parameters of the wastewater, including the concentration of microplastics in the shape of tent fibers (PVC), were calculated before and after filtration. The microfiltration membrane manifested a greater decrease in permeability (95%) compared to the ultrafiltration membrane (37%). The resulting water quality in terms of Total Solids, turbidity, and microplastics concentration was better for the ultrafiltration. This is evident from 99.2% versus 98.55% removal efficiency of microplastics from the laundering wastewater, respectively.
... In recent years, membrane technologies have been studied and applied in various industries [1,2]. The dual membrane ultrafiltration (UF)/reverse osmosis (RO) process has been used to improve the quality of reclaimed water [3]. ...
... When SF has been applied for water or wastewater treatment, it has shown promising results for treating organic carbon and ammonia nitrogen using adjusted hydraulic and organic loadings [39]. However, SF is not very effective for the removal of colloidal (particle size = 0.001 μm to 1 μm) and dissolved solids (particle size b 0.001 μm) [2,39]. Thus, an appropriate pre-treatment design is required for the application of RO systems for further reclamation of nano-particle-containing BG wastewater. ...
Article
Reverse osmosis (RO) membrane technology cannot be applied for the direct purification of nano-scale particle-containing wastewater due to membrane fouling/clogging problems. In this study, a three-stage pre-treatment process was developed to remove nano-scale particles from wastewater prior to further water purification using RO. The proposed pre-treatment system involved chemical coagulation/flocculation followed by sand filtration (SF) and ultrafiltration (UF). Backgrinding (BG) wastewater, which contained high concentrations of inorganic nano-particles, was used to evaluate the feasibility of this three-stage process for nano-scale particle removal. The BG wastewater (collected from a semiconductor manufacturing plant) had turbidity and suspended solids concentrations of approximately 1403NTU and 77.8mg/L, respectively. Up to 98% of the turbidity and particles could be removed through chemical coagulation/flocculation when 2.2mg/L of polyaluminum chloride was used as coagulant and 0.5mg/L of polymer was used as flocculant. However, the SF system could not effectively remove the nano-scale particles from BG wastewater directly. More than 99% of the turbidity and particles could be removed with the application of a UF unit [spiral-wound (SW) or hollow-fiber (HF) membrane] after the coagulation/flocculation/SF processes. Results indicate that the three-stage system is appropriate for the pre-treatment of nano-particle-containing wastewater.
... Common procedures include recipitation/coagulation, flocculation and adsorption on active carbon and membrane filtration. (Šostar-Turk et al. 2005, Hoinkis et al. 2008 b) Impact of detergentsdetergents have to be considered in assessment of environmental impact because they may become part of waste water. Unless the released waste water is properly processed, it may contain harmful substances, such as ammonia and phosphorus (Šostar-Turk et al. 2005). ...
... Besides this measure, purified waste water containing detergents may also be reused in a bath. (Hoinkis et al. 2008) c) Flue gascarbon footprint has to be considered when opting for energy source (electrical, heat) (Gil-López et al. 2012). For example, natural gas out of all fossil fuels has the lowest carbon footprint. ...
Article
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Professional laundry service (i.e., doing laundry for hospitals, hotels, production plants, dormitories, and students cafeterias) is an industrial, energy intensive process. Electrical energy and natural gas are commonly used to heat water and drying air. However, much of the energy leaves the process in waste flows completely without any profit. Professional laundry service has also direct impact upon environment. Waste water is often contaminated with laundry detergents and natural gas flue gas is used as drying medium. Therefore, it is an energy intensive process and its energy consumption and related environmental impact are worth researching. This article presents the concept of professional laundry service and main energy efficiency measures that may be relevant for the process. Impacts of laundry process on environment along with financial aspects are assessed in this article, too. Financial parameters of any measure are crucial for laundry operators. However, every assessment of profitability of particular measure has to be substantiated by source operational data. These may significantly vary depending on local prices of energy, water, and human labor. This fact is presented using case study where the difference between real operational costs in three European countries is evaluated (Germany, France, and the Czech Republic). Successful research and development of energy efficient and environmentally friendly technologies must encompass three aspects of every technology, i.e., energy intensity, environmental impact, and financial aspects. This three-component approach and its application in laundry service are unique and since they have not subject to any academic research yet, they are discussed in the conclusion of this article. Article is basically an overview of energy efficient and environmentally friendly technologies in professional laundry service and it must be asserted that it is a first of a kind in this area.
... The membrane-based reverse osmosis (RO) process is widely applied in effluent treatment in various industrial fields, such as plating, textile, sugar and distillery industries [37,49,102], or in the removal of trace level of micro pollutants, such as pharmaceutical compounds [72,73,113] and pesticide residues [31,79]. However its application is not well controlled in face of filtration of uncharged small organic solutes (molecular weight below 180 g·mol −1 ). ...
... It is also implemented for the treatment of effluents of various industrial fields, in order to achieve water reuse. For example, in plating industry, it is used to remove mixed chromic acid to produce rinsing water of high quality [37]; in textile industry it is applied for water reclamation [49]; in beet sugar and distillery industry, it is studied for the removal of small organic solutes from distillery condensates, to be reused as dilution water into the fermentation step [102]. Its broad applicability in industrial waste-water treatment also includes the removal of trace levels of micro pollutants, such as pharmaceutical compounds [72,73,113] and pesticide residues [31,79]. ...
Thesis
Commercial reverse osmosis (RO) membranes typically consist of an active aromatic polyamide layer (APA, thickness ∼200 nm), polymerized on a porous polysulfone support, itself attached to a polyester backing fabric. RO membranes are widely used in industrial waste-water treatments and their performances are essentially dominated by the active APA layer. However, neutral organic molecules rejections and the corresponding transfer behaviors are difficult to predict. In this work, we combined experimental structural characterizations and molecular modeling investigations on APA films, in order to improve transfer understanding at molecular level.APA layer of commercial CPA2 RO membrane and a set of free-standing APA films synthesized at four organic solvent temperatures (-20°C, 0°C, 15°C and 29°C) were investigated. Their structural properties including the morphology, topology, thickness, roughness, void fraction, effective density, dense layer density and chemical structure were characterized via various techniques such as Field Emission Scanning Electron Microscopy (FE-SEM), Atomic Force Microscopy (AFM), Profilometry, Spectroscopic Ellipsometry, Dynamic water sorption (DVS), X-ray photoelectron spectra (XPS) and Atomic force microscopy-based infrared spectroscopy (AFM-IR). Both film types had a multi-level topological structure with a dense base upon which generates: a valley-ridge structure for CPA2 or a chimney-like structure for synthesized samples, for which thickness and chimneys size increased with temperature. Based on the obtained average void fraction of 35% and the apparent volumetric density of 0.81 g·cm-3, the density of the dense regions of CPA2 APA layer was calculated at 1.25 g·cm-3 when dry and 1.48 g·cm-3 when hydrated. This completes the very few experimental density values found for the dense part of commercial APA films. With the help of a new set of chemical structure descriptors, the chemical depth-heterogeneity of CPA2 APA layer was investigated. The film synthesized at -20°C performed a remarkable water uptake of 65% at 91%RH, which might be attributed to its orderly distributed and small-size chimney morphology on top-surface.All-atoms molecular models of APA polymer were constructed by forming amide bonds between trimesoyl chloride (TMC) and m-phenylenediamine (MPD) with a set of initial MPD:TMC monomers ratios, varying from 0.25 to 5. The purposes were, on one hand, to mimic APA’s possible depth-dependent heterogeneous structures with boxes of different cross-linking degrees; on the other hand, to understand the effect of different initial monomer proportions during the IP on APA film’s structure. Several steps were necessary in order to obtain equilibrated samples, including a very long (several microseconds) constant stress and temperature molecular simulation. Final MPD:TMC (connected) ratios ranging from 0.68 to 2.61 were observed, corresponding to systems with acyl/amine group connectivity degrees at 45%/100% or 99%/57%, respectively. These results were consistent with chemical structure evaluation of real APA films. A similar density around 1.26 g·cm-3 were observed for all systems, consistent with the experimental density of CPA2 APA.Water sorption isotherms were computed using Monte Carlo method in osmotic ensemble for several simulated polymer matrixes and were obtained via DVS for experimental layers. At low water activity, water sorption behaviors of simulated polymers were in agreement with experimental data, validating the overall simulation methodology. At high water activity, water absorption was underestimated by molecular simulations. This could be attributed to the existence of void space in real APA films. No significant swelling was observed in simulations, which was in agreement with our experimental results for CPA2.
... Firstly basic findings of a full scale combined MBR/RO water reuse system in a commercial laundry in Darmstadt, Germany will be reported. This project "Laundry innovative wastewater recycling technology" (LIWATEC) has been realized within an EC funded project in the LIFE programme [3, 8,9]. In addition results of pilot trials will be summarized which were conducted in a Chinese textile factory in Changzhou within another EC funded project "Technology partnership for innovative treatment of drinking and industrial water (INNOWA) in the AsiaProEco programme [10]. ...
... This integrated process has been developed through cooperation between the Karlsruhe University of Applied Sciences and Textil-Service Klingelmeyer. Within the project, extensive research was undertaken to study membrane processes at bench and pilot scale in order to produce effluent suitable for direct reuse in the laundry [8,9]. The wastewater is treated in a two-step process and is recycled in the laundry´s washing and rinsing process (see Figure 1). ...
Article
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Membrane bioreactor technology (MBR) a combination of the activated sludge process with micro- and ultrafiltration is widely regarded as an effective tool for industrial water treatment and water reuse due to its high product water quality and low footprint. Due to their robustness and flexibility submerged MBR systems are more and more preferred. This paper highlights two case studies for industrial application in a commercial laundry and in a textile factory. A large-scale integrated water reuse process based on MBR+RO technology (capacity 200 m3/d) has been designed and established in a German laundry within an EC funded project eventually resulting in a reuse ratio of around 80% of the total wastewater. The process was in full operation at the beginning of 2007 and has been operated economically since that time without any failure. Within another EC funded project a small-scale MBR (capacity up to 0.4 m3/d) has been successfully tested in a Chinese textile factory. Despite high concentration of low biodegradable chemical in the wastewater, the COD removal rate achieved around 90%. However, the MBR permeate quality was not as high as in the laundry due to remaining colored dyestuff what makes an additional treatment step such as nanofiltration or reverse osmosis necessary in order to increase the proportion of reused water. In order to improve rejection of low molecular weight organics Karlsruhe University of Applied Sciences and the Institute of Membrane Technology have started a new EC funded project within a consortium of 11 partners in total which aims at developing novel membrane materials providing a basis for the development of a NF MBR reactor.
... Membrane bioreactors (MBR), moving bed bioreactors (MBBR) as well as sequencing batch reactors (SBR) have been used for aerobic laundry wastewater treatment. Pilot MBR plant with microfiltration membrane reduce the COD of raw laundry wastewater by around 90%. [14]. Part of the MBR permeate was subsequently treated by reverse osmosis (RO) filtration [14]. ...
... Pilot MBR plant with microfiltration membrane reduce the COD of raw laundry wastewater by around 90%. [14]. Part of the MBR permeate was subsequently treated by reverse osmosis (RO) filtration [14]. Results of MBBR test showed the possibility of reducing BOD to 12.7 mg/L and TOC to 6.8 mg /L [15]. ...
Article
Full-text available
Large laboratory scale biological treatment test of industrial real wastewater, generated in industrial big laundry, has been conducted in the period of May 2016–August 2016. The research aimed at selection of laundry wastewater treatment technology included tests of two-stage Moving Bed Bio Reactor (MBBR), with two reactors filled with carriers Kaldnes K5 (specific area – 800 m2/m3), have been realized in aerobic condition. Operating on site, in the laundry, reactors have been fed real wastewater from laundry retention tank. To the laundry wastewater, contained mainly surfactants and impurities originating from washed fabrics, a solution of urea to supplement nitrogen content and a solution of acid to correct pH have been added. Daily flow of raw wastewater Qd was equal to 0.6–0.8 m3/d. The values of determined wastewater quality indicators showed that substantial decrease of pollutants content have been reached: BOD5 by 94.7–98.1%, COD by 86.9–93.5%, the sum of anionic and nonionic surfactants by 98.7–99.8%. The quality of the purified wastewater, after star-up period, meets the legal requirements regarding the standards for wastewater discharged to the environment.
... Increasingly stringent environmental legislation and generally enhanced intensity, efficiency, and diversity of treatment technologies have made the reuse of water more viable in many industrial processes. In particular, the textile and laundry industries, which are widespread in the Middle East and North African (MENA) countries as well as in Asian countries such as China, India etc. [1], can be considered as water intensive factories because they release a high amount of wastewater [1][2][3][4][5]. For 12-20 tons of textiles produced per day, an estimated 1000-3000 m 3 wastewater are produced [6,7]. ...
... Membrane technology has been applied recently in wastewater treatment together with conventional treatment and can be regarded as a very promising technology for wastewater treatment and reuse, especially in the textile and laundry industries [2,[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. MBR technology is a combination of the conventional biological sludge process, a wastewater treatment process characterised by the suspended growth of biomass, and a micro-or ultrafiltration membrane system [12]. ...
Article
Due to a worldwide growing population and the resulting rising demand for fresh water, the treatment of wastewater is becoming more and more important to meet the water demand in many countries that have limited access to freshwater sources. In several processes, as in textile industries, the produced wastewater is treated by membrane bioreactors (MBRs). However, the membrane life-time and performance are strongly influenced by the fouling issue and, for this reason innovative approaches have to be considered for producing antifouling membranes. In this work, a novel polymerisable bicontinuous microemulsion (PBM) with antimicrobial properties was coated onto a commercial polyethersulfone (PES) UF membrane by using a UV-LED polymerisation system. The energy efficient UV-LED based process allows curing within a shorter time by selecting the optimal photoinitiator, curing time, coating thickness and temperature. The improved anti-fouling propensity was verified by water permeability experiments with humic acid as model foulant. The stability of the novel PBM coating was proven by FTIR analysis subsequent to chemical cleaning at pH 1 and 13. The novel PBM surface modification technique can be considered as a great step forward in the scale-up of a process thanks to the possibility of integrating into existing membrane production plants.
... The concentrate after RO is sent to a municipal treatment plant, and the surplus sludge is collected by commercial waste management companies Membrane filtration ( Figure 5.2) is more advantageous when compared to conventional treatment methods considering their fulfilment of higher standards, reduced environmental impact and possible application as mobile treatment units (Sostar-Turk et al., 2005). Studies have indicated that membrane filtration gives such good quality permeate that laundries are enabled to re-use their wastewater for laundering purposes (Ahn & Song, 1990;Hoinkis & Panten, 2008). Pre-filtration (particle filtration) is essential to ensure that subsequent membranes used do not get blocked. ...
... An example of a modern approach to wastewater recycling at a large commercial laundry(Hoinkis & Panten, 2008). ...
Technical Report
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This NATSURV (National Survey) document forms part of a series of such documents reporting on surveys of various industries in South Africa. In many instances, previous surveys were undertaken between 1986 and 2001. The purpose of the new NATSURV documents is to provide more recent and relevant information on water, wastewater, and energy management practices to all stakeholders involved in the chosen industries.
... Membrane technology has been recently applied in wastewater treatment as an efficient alternative to conventional treatment. Hence membrane technology can be regarded as a promising technolog y for waste treatment and reuse in textile and laundr y industries [2]. ...
Conference Paper
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A pilot-scale membrane bioreactor (MBR) was developed in order to run two membrane modules in parallel for the treatment of model textile wastewater (MTDW). Two independently operated commercially available ultrafiltration membrane modules called UP150 from Microdyn-Nadir where tested in the same activated sludge tank over a period of 70 days for their removal efficiency of the MTDW. In general the results of both membrane modules are in very good agreement. The water permeability ranged between 20 – 50 L/(m 2 .h.bar). Typically, the chemical oxygen demand (COD) removal efficiency indicated good biodegradation performance above 95%. The nitrification rate depended on the food to microorganism (F/M) ratio i.e. below 0.2 kg COD/(kg MLSS.d) the system showed complete nitrification. However, the color rejection for the model dyes was only around 20% to 60% what can be attributed to the low biodegradability of these chemicals. The next step is to run the MBR with novel nanostructured membranes in parallel with the commercially available membrane to compare their performances. This study contributes to sustainable development in the textile industry by improving water quality of treated textile wastewater what helps to reduce fresh water consumption and pollutant discharge.
... Results showed that excellent effluent quality could meet the reuse water standard in China. [43] studied the design and start up a new, innovative, integrated process using membrane technology for wastewater reuse on a large scale in the Klingelmeyer laundry, Germany. The MBR permeate provides a water quality that can be used as washing water since it fully meets the requirements of the washing process. ...
Article
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This study demonstrated the importance, process, activation and applications of Membrane in bioreactor to treat the waste water. Membrane Bioreactor (MBR) process consists of a biological reactor integrated with membranes that combine clarification and filtration of an activated sludge process into a simplified, single step process. Operating as an MBR allows conventional activated sludge plants to become single step processes, which produce high quality effluent potentially suitable for reuse. Application of MBR technology for industrial wastewater treatment has also gained attention because of the robustness of the process. Theoretically, maintenance of long SRT in MBR is in favor of the retention and development of special microorganisms, which may lead to better removal of refractory organic matter and make the system more robust to load variations and toxic shocks. Literature suggested the conceptual expectation of enhanced biodegradation of hardly biodegradable compounds in MBR does not often come true. Improved biodegradation to certain extent has been reported in a few studies; however the underlying factors leading to such improvement still remains to be elucidated. This is comprehensive review of the studies dealing with recalcitrant industrial wastewater treatment by MBR, and casts light on the strategies to achieve enhanced biodegradation of hardly biodegradable industrial pollutants in MBR.
... the cost of water production by seawater reverse osmosis units or by an evaporator (2–3 D per 1 m 3 ). Membrane fouling will have a less pronounced effect on the microfiltration membrane and the subsequent use of a submerged membrane bioreactor (MBR). To date, very limited studies have used submerged MBR for laundry wastewater treatment (Table 1). Hoinkis and Panten (2008) employed a 125 m 3 submerged MBR for laundry wastewater treatment and found that the average chemical oxygen demand (COD) removal efficiency was approximately 90% in 130 days and that the average flux was approximately 14 L/m 2 h at a transmembrane pressure lower than 50 mbar (Table 1 ). Cleaning the MBR unit was not necessary after 6 m ...
... Coagulation is used to convert small particles to larger particles prior to solids removal processes such as sedimentation, rapid filtration, or membrane filtration [2,7,8,13]. Contaminants in most raw waters and wastewaters are negatively charged, resulting in electrostatic stabilization of the suspension. ...
Article
The principal objectives were to identify optimal treatment of laundry wastewater using coagulation and microfiltration (MF) so as to decrease fouling, increase critical flux, and increase contaminant removals. Experiments were designed to simulate operation of the Army’s shower water reuse system (SWRS) which operates using constant-flux MF membranes with 0.22 μm pores. The SWRS is a transportable wastewater treatment system that is used in remote locations. Critical flux was measured using quick step-flux tests and also using multi-cycle tests with the objective of identifying rapid methods for evaluating design and operation of coagulation/MF systems. Low molecular weight quaternary amine polymers were effective coagulants that resulted in low coagulant doses, low chemical volume, and good coagulation/MF using a range of doses. Charge-neutralization (CN) and under-dosing (UD) at 40% of CN improved contaminant removals, decreased fouling, and increased critical flux from 45 L m−2 h−1 (LMH) for raw wastewater to a maximum 450 LMH using CN. The increased critical flux and good results over a wide range of coagulant doses can result in up to a 10-fold increase in water production for each SWRS unit and robust operation even in remote locations and with limited technical backup and perhaps changing water quality conditions. Low coagulant doses result in decreased transportation and storage requirements. In addition to practical application to the SWRS and similar operations, the results demonstrated the utility of quick step-flux tests for design and operation testing.
... Most of these technologies are preceded by a solid-liquid separation step as pre-treatment and followed by a disinfection step as a post-treatment [2,12]. Reported methods are aerobic treatment coupled with UV, ozone or chlorine disinfection, anaerobic digestion, adsorption on active carbon, photooxidation (UV/H 2 O 2 ), microfiltration, reverse osmosis and membrane coupled photocatalytic process [13][14][15][16][17][18][19][20]. ...
... A treatment of laundry wastewater in a membrane bioreactor (MBR) technology was also proposed [11][12][13]. Nicolaidis and Vyrides [13] presented the performance of a full-scale submerged aerobic MBR (9 m 3 ) applied for the treatment and reuse of industrial laundry wastewater. The system was examined over a period of 288 days. ...
... Various methods have been practiced for treating industrial wastewater and providing reusable water. This includes membrane technologies such as: micro-filter, ultra-filter, nano-filter and reverse osmosis (Barredo-Damas et al., 2010;Borsi et al., 2012;Braeken et al., 2004;Fersi and Dhahbi, 2008;Kim et al., 2005;Nandy et al., 2007), chemicals and photo-chemicals processes (Erdogan et al., 2004;Rodrigues et al., 2008), biological treatment units (Badani et al., 2005) and integrated systems (De Nardi et al., 2011;Hoinkis and Panten, 2008;Souilah et al., 2004;Sarkar et al., 2006;Zhang et al., 2011). ...
... With a growing concern for water resources, water reuse is becoming a major challenge for a lot of industries such as textile [1], metal plating [2,3], laundry [4] or agro-industry [5][6][7][8]. ...
Article
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Reverse osmosis (RO) is an interesting process to eliminate small organic solutes (carboxylic acids and alcohols) from distillery condensates before recycling them into the fermentation step. This work investigates the influence of transmembrane pressure, pH and volume reduction factor (VRF) on the efficiency of reverse osmosis treatment of condensate from distillery stillage concentration at pilot scale using three pre-selected membranes (CPA2 and ESPA2 from Hydranautics, BW30 from DOW). Performances were assessed according to permeate flux, solutes rejection and abatement of fermentation inhibition. Transmembrane pressure increase leads to an increase of these three parameters with a plateau for rejections and abatement at 20bar; however, in order to comply with membranes manufacturer's recommendations and to limit or delay polarization and fouling, it was decided to keep the permeate flux below a value of 30Lh−1m−2. This corresponded to a maximum pressure of 10bar for CPA2 and ESPA2 membranes and 25bar for BW30 membrane. pH increase leads to a diminution of permeate flux and an increase of carboxylic acids rejection whatever the membrane; nevertheless, no abatement of fermentation inhibition is observed. Increasing VRF provokes a decrease of the permeate flux. Although local rejections are stable, the mean rejection assessed with the raw condensate (feed) and the mean permeate decreases. However, the fermentation inhibition remains under 10% up to a VRF of 8. BW30 membrane exhibits the highest rejections and inhibition abatement. On the basis of the pilot scale results with the BW30 membrane, a preliminary estimation of the membrane area is proposed for an industrial plant with 100m3h−1 of condensate flow rate and the optimized parameters (pressure 25bar, no pH modification, VRF 4 and 8).
... The implementation of membrane (micro-/ultra-filtration) for solids retention into biological treatment system leads to several substantial improvements compared to conventional biological processes [1]. However, application of state-of-the art MBR technology for textile wastewater treatment as a single-step process is rather limited and typically requires downstream post-treatment such as nanofiltration or reverse osmosis systems [2], combined anaerobic-aerobic MBR processes [3,4] or modified MBR membranes. ...
... In this study, HRTs from 4 d to 0.4 d were tested whereas the SRT remained infinite. The membrane fluxes (up to 6.9 L m À2 h À1 ) were comparable to those of both pilot-scale as large-scale MBRs working with the same microfiltration plate membranes (14 L m À2 h À1 ) ( Hoinkis and Panten, 2008). The maximum EE2 removal efficiency (97.7%) in case of an influent concentration of 100 mg EE2 L À1 was noticed in period B4, when 0.8 mg NH 4 þ-N L À1 was dosed in the influent. ...
Article
Increasing concern about the fate of 17alpha-ethinylestradiol (EE2) in the environment stimulates the search for alternative methods for wastewater treatment plant (WWTP) effluent polishing. The aim of this study was to establish an innovative and effective biological removal technique for EE2 by means of a nitrifier enrichment culture (NEC) applied in a membrane bioreactor (MBR). In batch incubation tests, the microbial consortium was able to remove EE2 from both a synthetic minimal medium and WWTP effluent. A maximum EE2 removal rate of 9.0 microg EE2 g(-1)biomass-VSS h(-1) was achieved (>94% removal efficiency). Incubation of the heterotrophic bacteria isolated from the NEC did not result in a significant EE2 removal, indicating the importance of nitrification as driving force in the mechanism. Application of the NEC in a MBR to treat a synthetic influent with an EE2 concentration of 83 ng EE2 L(-1) resulted in a removal efficiency of 99% (loading rates up to 208 ng EE2 L(-1)d(-1); membrane flux rate: 6.9 L m(-2) h(-1)). Simultaneously, complete nitrification was achieved at an optimal ammonium influent concentration of 1.0 mg NH(4)(+)-N L(-1). This minimal NH(4)(+)-N input is very advantageous for effluent polishing since the concomitant effluent nitrate concentrations will be low as well and it offers opportunities for the nitrifying MBR as a promising add-on technology for WWTP effluent polishing.
... Additional membrane separation can also improve the separation efficiency of a wastewater treatment system with MBR unit. By adding RO separation after MBR treatment, Hoinkis and Panten (2008) demonstrated a process that recycled laundry wastewater for the same reuse purpose, at about 10% loss. Similarly, by applying NF to wastewater stream post-MBR treatment, greywater high in anionic and non-ionic surfactants could be regenerated with pollutant readings low enough (COD <50 mg/L, anionic surfactant <0.5 mg/L) for reuse as feed to cooling towers (Linclau et al., 2016). ...
Article
Rapid urbanization and the rising global population have led to the generation of substantial volumes of laundry wastewater. Accordingly, treatment of laundry wastewater has been advocated to curb water pollution and achieve water sustainability. However, technological limitations in treating (specifically) laundry wastewater and the lack of regulations governing the levels of contaminants for such discharges have been perennial problems. This review bridges the knowledge gap by delineating the feasibility of current technologies in laundry wastewater treatment and the experiences of various countries in adopting different approaches. Besides, the feasible methods for collecting laundry wastewater are elaborated. The development of the treatment technologies is highlighted, in which the integrated-treatment processes (physicochemical, biological, and combination of both) are critically discussed based on their functions and methods. A judicious selection of the technologies not only improves the energy efficiency and quality of the treated wastewater, but also mitigates capitals and operational costs. This is projected to enhance public acceptance towards the reuse of laundry wastewater. Thus, the comprehensive assessment herein is envisioned to insightfully guide national policymakers in exploring the viability of the technologies and water-recycling projects. Future research should focus on the techno-economic aspects of the treatment processes, especially their industrial scale-up.
... Another MBR has been successfully tested for 5 years in the form of two pilot plants at the laundry in Darmstadt, Germany. The COD removal efficiency was around 90% [4,9]. ...
Article
The application of membrane bioreactor (MBR) for industrial laundry wastewater treatment is presented. An MBR pilot plant installation was used to test the efficiency of surfactants removal and the influence of treatment time on permeate flux. The installation consisted of (1) biological reactor (three tanks with a total capacity of 600 dm³), (2) membrane reactor (ZeeWeed 10 membrane module, GE Water & Process Technologies), and (3) dosing station. The hourly flow rate of the wastewater to the biological reactor amounted to Qh = 25 dm³ h–1. The effluent from the bioreactor was periodically recycled back to the membrane reactor at Qh = 125 dm³ h–1. Despite periodical relaxation and back-flush with permeate, after about 11 d of operation the membrane was fouled and chemical cleaning was necessary. The membrane permeability was fully recovered after the applied cleaning procedure. The total efficiency of removal of anionic and non-ionic surfactants was in the range of 87%–95% and 94%–95%, respectively. The COD removal reached 91%–93% and the BOD was almost completely eliminated (99%) indicating high MBR treatment efficiency of the applied industrial laundry wastewater.
... Membrane technology has been recently applied in wastewater treatment as an efficient alternative to conventional treatment. Hence membrane technology can be regarded as a promising technology for waste treatment and reuse in textile and laundry industries [2]. ...
... Therefore, the sMBR was operated under sub-critical flux conditions during the study. Many industrial MBR systems were operated at low membrane flux (Wang et al., 2005;Hoinkis and Panten 2008). Membrane fouling rate determination was conducted at constant membrane flux (9.5 LMH) when the sMBR reached the steady-state condition. ...
Article
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In this study, an aerobic submerged membrane bioreactor (sMBR) was used for the treatment of dairy wastewater at 15 h of hydraulic retention time (HRT) and 40 d of sludge retention time (SRT) with constant permeate flux (9.5 L.m⁻³.d⁻¹(LMH)). The COD, ammonia-nitrogen (NH3-N) and orthophosphate (PO4-P) removal efficiencies were 98.2%, 95.4% and 88.9%, respectively. The results demonstrated that sMBR was a suitable and effective treatment for removal of organic matter and nutrients for treating dairy wastewater. The properties of the activated sludge, such as extracellular polymeric substances (EPS) and soluble microbial products (SMP) concentration, protein and carbohydrate, relative hydrophobicity, zeta potential and floc size distribution were also investigated. According to the results obtained, the total EPS content was lower than that of domestic wastewater treatment by MBR technology.
... CAS) [55]. However, application of state-of-the art MBR technology for wastewater treatment as a single-step process is rather limited and typically requires further treatment stages [56][57][58]. On the other hand, there is increasing concern that severe fouling is being the main hurdle for wider applications of MBR technology especially in high-strength wastewater streams that needs to be alleviated for real field application [59]. ...
Thesis
With its many advantages, membrane bioreactor (MBR) appears to hold potential for the treatment of wastewater from different effluents. Porous hydrophobic polyethersulfones (PES) membranes have been extensively used in commercialized MBR operations. However, these PES membranes are vulnerable to membrane fouling and pore-blockage in wastewater feeds, restricting its application for water recovery from challenging wastewaters. Different approaches have been proposed and studied extensively to overcome such a problem. Blending PES polymer with hydrophilic and amphiphilic additives is considered an effective way in solving PES fouling problem. To address these challenges, this work aims at developing novel PES based membranes that can be applied in MBR operations for wastewater treatment. Fundamental understanding of the effects of both kind and weight % of the additive and a PES membrane is traced extensively. The results reveal that additive concentration and hydrophilicity had an influence on membrane performance, fouling and structural changes behaviors of these modified membranes. Notably, all additives used could make the PES membrane surface less hydrophobic and cause less severe fouling by decreasing the attachment of foulant on the membrane surface. These findings suggest that membrane surface modification is required to achieve fouling-resistant properties for robust long-term applications. Inspired by cleaning protocols in real wastewater plants, we challenged the fabricated polymeric membranes with harsh cleaning condition (NaOCl, 400 ppm, 10 days). It has been found that the fabricated membranes possessed a withstanding behavior against NaOCl treatment as proved from FTIR results. In this thesis, twenty eight flat sheet membranes were fabricated, all by one blending process via NIPS technique. The fabricated membranes characters verified using different characterization techniques. These membranes exhibited better wettability than neat PES membrane preventing pollutants adhesion while insuring that water transport. The performance of the fabricated membranes was investigated via bench-scale dead end filtration experiments by feeding deionized water and a series of model pollutants solutions. In comparison to the pristine PES membrane, the modified polymeric membranes demonstrated better pure water permeability and lower BSA rejection. In order to improve the rejection ability of such polymeric membranes, graphene oxide (GO) has been added with different loadings. The main findings that have been elaborated from adding GO are both water flux and solutes rejection have been improved. Moreover, these MMMs showed better antifouling properties as verified from BSA adsorption and fouling-profiles data. This was ascribed to the formation of an interfacial hydration layer and deposition of functional groups within the membranes‟ hierarchical structures. This study demonstrates the potential of the modified membranes for extended MBR applications such as wastewater treatment. Finally, the performance of PES modified membrane with 5 wt% PLu was investigated in large scale prototype SMBR unit. The results showed that the primary treated domestic wastewater can be reused for agricultural irrigation without any disinfection process after passing through the SMBR unit. The bacterial removal, COD removal was 100%, and 88% respectively, with flux of 0.2 LMH in the presence of 2 g/L MLSS.
... Because, MBR has some major advantages than that of the CAS, including small footprint, superior quality effluents (no chemicals and chemical by-products), and sludge reduction (Drews, 2010;Jeison and Van Lier, 2007;Judd, 2010;Tewari et al., 2010). For example, the MBR processed water from an integrated process in Germany provided a water quality that fully meets the requirements of a washing process (Hoinkis and Panten, 2008). However, the MBR has the drawback of membrane fouling, leading to an increased energy demand due to increased trans-membrane pressure and influenced the removal efficiencies and nitrous oxide emission (Van den Broeck et al., 2012;Mannina et al., 2017). ...
Article
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The performance of a membrane bioreactor (MBR) was compared to a conventional activated sludge (CAS) process and it was aimed to identify the best technological option for a municipal sewage treatment plant (STP). The MBR system was fed by the diluted sewage coming from the main municipal sewer network, which contained an averagely lower concentration of organics, inorganics and biological pollutants. While the CAS system was fed by a concentrated sewage coming from household septic tanks, contained averagely high concentration of organics, inorganics and biological pollutants. CAS showed a higher removal efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), volatile suspended solids (VSS), Fat-Oil-Grease (FOG), nitrogen, phosphorous, helminths ova (HO), and pathogenic bacteria compared to the MBR. Nevertheless, the removal efficiencies of nitrogen, HO and pathogenic bacteria in the case of CAS were lower than MBR due to the high concentration of those parameters in the influent fed to CAS. However, both the efficiency and the amount of removal for phosphorous in the case of CAS was quite higher than that of MBR due to extended aeration in CAS. The pathogenic bacteria and HO were removed almost 99.97% by the MBR, whereas the CAS removed 91±5% of the pathogenic bacteria and HO. Therefore, the effluent of the CAS system required additional disinfection for the reduction of pathogens and HO. In terms of biological efficiency and influent flexibility, both the systems can satisfy the national standards. Overall, the data suggested that CAS possessed a higher capacity of treating concentrated sewage for removing all pollutants to satisfactory limits except complete removal of pathogenic bacteria and HO. It was obvious that MBR possessed a membrane barrier to retain the pathogens and HO; therefore, they could be removed up to very low levels. However, further investigation is necessary to verify the MBR performance using the same concentrated sewage as CAS.
Article
In this laboratory pilot-scale study, a hybrid treatment system has been developed to remove chlorinated solvent trichloroethylene and fine particles from chlorinated solvent trichloroethylene-contaminated groundwater before it is applied for further recovery. The two-stage system contained fiber-ball filtration followed by nanofiltration membrane processes. The measured chlorinated solvent trichloroethylene and suspended solids of the tested groundwater were 850 μg/L and 1,052 mg/L, respectively. Up to 97.3 % of chlorinated solvent trichloroethylene and 99.9 % of SS could be removed by the hybrid system with an operational pressure of 4.1 kg/cm2. The chlorinated solvent trichloroethylene removal mechanism in the fiber-ball filtration process could be due to adsorption. Approximately 98.2 and 78.6 % of chlorinated solvent trichloroethylene rejection was observed when nanofiltration membrane was used for chlorinated solvent trichloroethylene removal with the recover rate of 80 % and initial chlorinated solvent trichloroethylene concentration of 1 and 10 mg/L. Higher chlorinated solvent trichloroethylene rejection can be obtained when lower chlorinated solvent trichloroethylene concentration (1 mg/L) was applied. High chlorinated solvent trichloroethylene concentration (10 mg/L) would increase the pore size of nanofiltration, which causes the decrease in chlorinated solvent trichloroethylene rejection rate. Approximately 46.6 % of flux drop was observed when nanofiltration membrane was used along compared to the system using FF as the first treatment stage. This indicates that the application of fiber-ball filtration could maintain a higher flux of groundwater treatment. The developed fiber-ball filtration and nanofiltration hybrid membrane system is able to reduce the chlorinated solvent trichloroethylene and solid concentrations to meet the water reuse and groundwater remediation standards.
Article
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The present study deals with the feasibility to implement, on board ship, a direct nanofiltration process in order to treat laundry grey waters and recycle 80% to the inlets of the washing machines. At first, a specific methodology for real laundry grey water production was set up at the laboratory for the purpose. Characteristics of the lab-produced grey water are close to those observed on board (pH 7, 1300 mgCOD/L, 80 mgTSS/L). Then, a membrane screening in view of a selection was realised at the lab scale. A direct nanofiltration process (without pre-treatment) on tubular PCI-AFC80 membrane (35 bar, 25 °C, volumic-reduction-factor 5) allowed us to produce a permeate free of micro-organisms and suspended solids and with only 48 mgCOD/L and 7 mgTOC/L. Based on these satisfactory preliminary results, a techno-economic study was conducted (up-scaling) with the aim of producing daily 52 m3 of recyclable permeate from 65 m3 of polluted grey water. Finally, orders of magnitude, both for energetic consumption and processing costs, are proposed.
Article
Membrane bioreactor (MBR) technology has been extensively employed for various industrial wastewater treatments due to its distinct advantages over conventional technologies. To provide present state and development trends of MBR technology used for industrial wastewater treatments, the authors reviewed and analyzed more than 300 scientific publications. They present an overview of the most recent development of MBR technology for treatment of industrial wastewaters (e.g., food processing, pulp and paper, textile, tannery, landfill leachate, pharmaceutical, oily and petrochemical wastewaters). Moreover, they discuss the operational characteristics, fouling characteristics, fouling control strategies, and costs of MBRs in industrial wastewater treatments. Based on the present information on MBR technology, the authors discuss further research aspects of MBRs in industrial wastewater treatments.
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Marine pollution caused by the substandard discharge of domestic sewage from ships has received considerable attention in recent years. Thus, the research and application of efficient treatment and supervision system of domestic ship sewage are matters of considerable interest in marine pollution prevention. The environmental impacts of black and grey water on marine and river environments were reviewed to emphasize the urgency and importance of sewage treatment. Development and changes of emission indexes revealed the emphasis on marine environmental protection and domestic sewage discharge. Based on summarizing the difficulties of high salinity, high organic load and poor stability in ship sewage treatment, the technologies of physical-, chemical- and biochemical-based processing were reviewed. Case study of online monitoring system was displayed to provide research trends. The challenges and future perspectives were also provided to promote supervision and disposal of domestic sewage from ships.
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We use molecular dynamics simulations at the atomistic level to build a model of aromatic polyamide polymer used in reverse osmosis membranes, from a mixture of m-phenylene diamine (MPD) and trimesoyl chloride monomers (TMC). Our purpose is to use different MPD to TMC ratios to reproduce the compositional depth-dependence observed experimentally during interfacial polymerization. MPD to TMC ratios in the range 1:4 to 5:1 have been employed. Reproducibility of the polymerization algorithm is thoroughly studied through the building of several samples under identical conditions. We notice that simulation time of a few microseconds are necessary in order to reach equilibration. We show that the initial monomer ratio has a strong influence onto the final polymer composition and different chemical structures have been created. Large differences are seen concerning cross-linking degree and remaining un-reacted groups. Comparison with available experimental data show that samples built using intermediate values of the MDP to TMC ratio closely resemble aromatic polyamide membranes. We conclude that the simulated samples created under different local concentrations can describe properly the chemical heterogeneities observed experimentally in reverse osmosis membranes.
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Wastewater discharged from semiconductor industry contains high turbidity and conductivity. When membrane systems are used for semiconductor wastewater reclamation without pretreatment, membranes will soon be clogged by the nano-size particles. In this pilot-scale study, a three-stage system has been developed for semiconductor wastewater reclamation. This system (flow=5m3d−1) contained fiber ball (material: polypropylene, diameter=25mm) filtration (FF) followed by ultrafiltration (UF) and reverse osmoses (RO) units. The FF was installed as a pretreatment unit (first stage) for particle removal. Spiral wound (SW) UF (material: polyethersulfone) and RO membrane (material: polyamide) were applied in the second and third treatment stages, respectively. Up to 95.8% of suspended solid (SS) could be removed after the pretreatment by FF system with an 88mhr−1 filtration velocity. More than 95% of the remaining turbidity can be further removed after the following UF treatment (turbidity dropped from 30 to below 0.6NTU). After the treatment by RO unit, the effluent conductivity, turbidity, and total dissolved solid dropped to below 69.2μScm−1, 0.06 NTU, and 53.5mgL−1, respectively. Knowledge obtained from this study will be useful in designing the three-stage FF and UF/RO system for practical application.
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Accommodation providers produce large amounts of wastewater in laundering processes (12-25 L/kg of textile). The composition of this wastewater depends on the washing procedure. Between 2 and 100 mg/L methylene blue active substances (MBAS), between 1 and 30 mg/L total phosphorous, and up to 20,000 mg/L chemical oxygen demand (COD) have been reported. Many regions have regulated the concentration of surfactants and phosphorous that can be discharged into water bodies to a few milligrams per liter, due to the negative effects that these compounds can cause in the environment. Several techniques can be employed in laundry wastewater treatment, including coagulation, filtration, biological reactors, adsorption, or advanced oxidation processes. Frequently, a combination of the mentioned processes is needed to meet the desired water quality standards. Only a few studies have reported an economic assessment of the options employed for laundry wastewater reclamation. Lower costs have been reported for coagulation, biological reactors, and adsorption processes than for other treatments such as filtration techniques. Total treatment costs vary between €0.09/m3 (treatment with granular activated carbon) and €5/m3 (nanofiltration). Life cycle assessment (LCA) is important for decision-making when different alternatives can be applied. Few references include a LCA for laundry wastewater treatment. Electricity consumption has been reported as one of the main environmental hazards for laundry wastewater treatment: an equilibrium must be reached between energy consumption and the standards of treated water. Future works must lead with the full-scale application and long-term monitoring of general, cost-effective, simple, and environmentally friendly techniques for the treatment of industrial laundry wastewater.
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The complex structure of the active aromatic polyamide (APA) layer of reverse osmosis membranes needs to be precisely described for understanding and predicting solutes rejection. A commercial reverse osmosis membrane (CPA2-Hydranautics) was chosen as a case-study, and home-made APA films prepared by free-standing interfacial polymerization of trimesoyl chloride (TMC) and m-phenylenediamine (MPD), at different temperatures in order to obtain different film structures. Their morphology, thickness, void fraction, density and chemical composition were characterized with scanning electron microscopy (SEM), atomic force microscopy (AFM), profilometry, ellipsometry, dynamic vapor sorption (DVS) and X-ray Photoelectron Spectroscopy (XPS). All samples have a multi-level topological structure as a dense base upon which generates: a valley-ridge structure for CPA2 and a chimney-like structure for synthesized samples, whose thicknesses increase with temperature. An average void fraction of 35% was deduced for the APA from CPA2, allowing the calculation of a dry density of its dense phase of 1.24 g∙cm-3, rarely investigated for commercial membranes. New chemical descriptors considering chain heads, tails and branches were introduced to improve the interpretation of chemical composition results. More realistic than the cross-linking degree, they suggested for CPA2 active layer a back-surface chemically less cross-linked than the top-surface.
Conference Paper
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The treated wastewater provides environmental benefits by providing additional nonconventional source of water which helps to overcome water scarcity challenge. Moreover, it decreases discharged pollution and reduces adverse impacts on human health. The objective of this study is to evaluate wastewater treatment technologies which are Conventional Activated Sludge (CAS) and Membrane Bioreactor (MBR). The project emphasises on characterizing the strength of raw sewage, compare the quality of treated effluent to Standards and evaluate the removal performance. The results showed that raw sewage of CAS can be categorized as high strength concentrate but as medium strength concentrate by MBR. Both technologies produce very good quality of treated effluent since most parameters showed compliance with standard. The removal efficiency achieved at CAS for TSS, TN and BOD are 97%, 57% and 98% respectively, while that accomplished at MBR are 98%, 82% and 98% respectively. However, the removed amounts of the TSS, TN and BOD in CAS were 437, 40 and 442 kg/ 1000 m3 respectively compared to 147, 37 and 206 kg/ 1000 m3 respectively, for MBR. The CAS system presented superior performance to the MBR in almost all of the investigated criteria, except for nitrogen removal. Further investigation is needed to ensure that the MBR process is flexible enough to achieve similar volumetric removal as the CAS system under similar operating conditions, so that both technologies can be considered as solutions contributing towards sustainable water management.
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Recycled water provides a viable opportunity to supplement water supplies as well as alleviate environmental loads. The authors examine the sources of recycled water and discusses various end uses. They focus on reviewing the historical development and current status of recycled water on a global scale with containing the evolvement of wastewater treatment technologies, water quality guidelines, and public attitudes. The authors also illustrate typical case studies of recycled water in a number of countries and regions, including Australia, Asia, the United States, Latin America, Europe, the Middle East, and Africa. These pilot studies can be good examples for the future projects. They identify the good prospects of further expansion and exploration of current and new end uses while emphasizing the integrated water planning and management as well as challenging and tasks in the future.
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The aim of this study was to investigate the treatment and reuse of laundry wastewater with couple of nanofiltration (NF) and reverse osmosis (RO). In the NF process, optimal values of pH, temperature, transmembrane pressure (TMP) and cross-flow rate were determined using the Taguchi L16 (44) experimental design method. The smaller-the-better signal-to-noise (S/N) ratio was used to analyze the results of experiments. Flux decline caused by fouling was selected as response parameter. A pH of 8.5, temperature of 30 °C, TMP of 12 bar and cross-flow rate of 2 L/min were determined as optimum operating conditions in the NF process. According to analysis of variance (ANOVA), pH was the most effective factor while TMP and cross-flow rate had low effects on the fouling. Membrane fouling was also evaluated with scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), zeta potential and optical profilometer measurements. In the RO process, the quality of NF permeate obtained from optimum operating conditions was improved by an RO membrane. Although a NF membrane was not effective in reducing chemical oxygen demand (COD), Orto-P and NH4+-N, these parameters were almost removed in the NF + RO system. These results showed that, the Taguchi method was successfully applied to determine the optimum operating conditions for the treatment of laundry wastewater with an NF process. Water treated with integrated membrane processes (NF + RO) is sufficient for use as laundry washing water.
Article
Different molecular weight cut-offs (MWCO = 2–30 kDa) flat sheet membranes and hollow fibre modules were applied for filtration of surfactant aqueous solutions (Triton QS-44, CTAB and Triton X-100). The experiments were performed in a stirred cell (dead-end regime) and in a semi-pilot membrane installation (cross-flow regime). The effect of the process conditions (transmembrane pressure and cross-flow velocity) and the interaction between the membranes’ polymer and surfactants under a wide range of concentrations on ultrafiltration effectiveness was evaluated. The results demonstrated that the highest retention coefficient of anionic and cationic surfactants was obtained with the hydrophobic membranes; however, hydrophilic membranes were characterised by distinctly higher retention of the non-ionic surfactant. It was proved that with a good adjustment it is possible to determine, with the help of a linear dependence, the concentration of a surfactant in the permeate depending on the concentration in the feed solution.
Article
In this work, domestic laundry wastewater was treated through a membrane process using a mixed cellulose ester (MCE) microfiltration membrane with 0.22 μm pore size. A cross flow filtration was used and the effect of operating parameters such as trans-membrane pressure (TMP) and feed flow rate on permeate flux and rejection characteristics have been studied. A detailed analysis of the membrane fouling and the formed resistances against permeation which caused flux decline including membrane, cake layer, reversible and irreversible resistances have been offered and the effect of trans-membrane pressure and flow rate on each of the mentioned resistances was examined. Finally, the removal efficiencies for BOD, COD, TSS and turbidity at different trans-membrane pressures and feed flow rates are determined. It was observed that an increase of TMP and feed flow rate has positive effects on the permeate flux and membrane rejection performance. Moreover, the overall resistance increases with an increase in TMP and decreases with an increase in feed flow rate. The highest removal efficiency for BOD, COD, TSS and turbidity was obtained as 93.9, 90.8 and 98.7 percent, respectively which was obtained at a TMP of 1 bar and feed flow rate of 44 L/h. Modeling of the microfiltration system by the Hermia models revealed that the cake formation model (CFM) has the best agreement with the experimental results and it could be concluded that the cake layer formation on the membrane surface is the main mechanism for membrane fouling and flux decline. The results of this study showed that the microfiltration is a reliable and simple operation for recycling and reuse of domestic laundry wastewater in mixture with fresh water for use in washing machines, toilets and irrigation.
Article
The pollution of laundry wastewater is dependent on the origin of the linen, soil degree of the linen and the laundering process. It is caused by dissolved organic and inorganic substances, as well as sedimented and toxic substances. Washing detergents contain various chemicals used in great quantities whose influence on the environment is very important as they are transferred into wastewater treatment plants after use and are, therefore, also present in effluent, where they add their contribution to the total toxicity of the effluent. This review paper summarizes the findings of various literature and presents the biodegradation of most often used surfactants. In order to assess their environmental risks, we need to understand the distribution, behaviour and degradation of surfactants in the different parts of a wastewater treatment plant.
Article
An aerobic membrane bioreactor (MBR) system has been equipped with low cost water filter units available in local market and tested as a bench-scale unit in a medium size laundry. The purpose of the study is to verify their potentiality for application in MBR systems as an alternative to polymer membrane modules. The performance of the system is evaluated in terms of flux recovery and COD level of the treated water. Cleaning operation is performed by mechanical rubbing/brushing and backflushing. In each operational cycle, the flux is found to deteriorate gradually due to fouling. Mechanical rubbing/brushing results in partial elimination of the fouling and thus partial recovery of the flux, while backflushing to remove the fouling causes internal damage to the filters. Fouling leads to an improvement in the COD removal. It is concluded that the filter units, if modified, could be used in MBR systems, and success of low cost filter-based MBR system would inspire countries with cheap labor to build wastewater treatment plants with their own capacities.
Article
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Elektrokoagulasi adalah teknologi pengolahan air dengan menggunakan proses elektrokimia dimana anoda akan melepaskan koagulan aktif berupa ion Al atau Fe ke dalam larutan. Tujuan penelitian ini adalah mengetahui laju penurunan konsentrasi deterjen, COD dari air limbah yang diolah pada reaktor elektrokoagulasi dan mengetahui parameter desain elektrokoagulasi yang sesuai untuk pengolahan air bekas cucian dalam skala rumah tangga. Reaktor elektrokoagulasi dioperasikan secara batch dengan menggunakan limbah dari jasa laundry. Elektroda yang digunakan adalah aluminium dengan kemurnian 99.7%. Variasi kerapatan arus yang digunakan adalah 50, 75 dan 100 A/m2. Parameter yang diukur adalah surfaktan, COD, kekeruhan, konduktivitas, pH dan suhu. Hasil percobaan menunjukkan bahwa untuk konfigurasi monopolar dan bipolar dengan waktu detensi 30 menit tingkat penyisihan surfaktan mencapai 70%, sedangkan COD mencapai 80%. Berdasarkan tingkat penyisihan, reaktor elektrokoagulasi dengan konfigurasi monopolar dan bipolar tidak menunjukkan perbedaan yang signifikan pada pengolahan air limbah laundry.
Article
One of the most promising strategies for maintaining stable water sources for on-site wastewater reuse is greywater reclamation, particularly laundry wastewater reclamation. This study proposes an efficient strategy for the pre-treatment of laundry wastewater, which reduces membrane fouling and improves flux recovery after membrane cleaning. The fouling behavior, organic retention, and flux recovery rates of ceramic ultrafiltration (UF) membranes were comprehensively investigated using synthetic laundry wastewater. Under identical applied pressure and temperature conditions, a fouling resistance that corresponded to the water permeate flux and normalized flux was explored. Total organic carbon (TOC) retention was also tested to investigate the feasibility of using ceramic UF membranes as an effective pre-treatment for laundry wastewater reclamation. Furthermore, four different cleaning strategies for the fouled ceramic membranes were systematically compared, including deionized (DI) water, alkaline, acidic, and combined alkaline and acidic chemical agents to provide an in-depth understanding of the potential recovery rates of the membranes relative to the initial state. The filtration and treatment performance of real laundry wastewater samples collected from a university student dormitory was compared with synthetic laundry wastewater. This work provided valuable information on fouling behavior and cleaning strategies that could advance ceramic UF membrane pre-treatment technology for sustainable laundry wastewater reuse. Despite the challenges associated with the organic fouling and the potential of incomplete flux recovery in engineered systems, our findings provide insights into fouling mechanisms and cleaning strategies that could enable the optimization of engineered wastewater reuse systems.
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.
Article
A critical review of literature on the separation of surfactants from aqueous streams by membrane processes is given. These processes are ultrafiltration (UF), miceller enhanced ultrafiltration (MEUF), and reverse osmosis (RO). The factors which affect the permeate flux and rejection of the surfactant and/or electrolyte are considered in detail. With the exception of MEUF studies, most of the published work on surfactant separation lacks input from surfactant and interface science. These studies indicate that the fouling (gel) layer on the membrane and within the pores essentially controls the permeate flux and rejection characteristics of the separation system. It is therefore essential to understand the physical-chemical nature of the gel layer which is probably a direct result of surfactant and electrolyte concentrations and temperature on the surfactant phase behaviour. The present review also indicates that the mechanism of water and/or surfactant transport through the membrane and gel layer has not been considered.
Article
Recycling of process streams and reduction of waste disposal using membrane technology in a continuous textile washing process after dyeing with reactive dyes have been investigated theoretically. A mathematical process model of a conventional open-width washing range has been extended by membrane processes to determine the benefits and limitations of the modified washing processes. The concentrations of hydrolysed reactive dyes, sodium chloride, urea and caustic soda have been calculated with this process model. Reverse osmosis for desalination and decolourising and nanofiltration for decolourising have been implemented as membrane technology. Reusing filtered wash water in a previous wash step results in more water saving than recycling to the same wash step according to the process calculations. The total fresh water demand can be reduced by 70% and the total waste water volume by 90% compared with the conventional process. Greater reduction of fresh water use is limited by the osmotic pressure difference between the retentate an permeate streams.
Article
This paper presents the results obtained from laundry wastewater treatment using conventional methods namely precipitation/coagulation and the flocculation process with adsorption on granular-activated carbon (GAC) and an alternative method, membrane filtrations, namely ultrafiltration (UF) and reverse osmosis (RO). Chemical analyses showed that parameter values of untreated wastewater like temperature, pH, sediment substances, total nitrogen and phosphorous, COD, BOD5, and the amount of anion surfactants had been exceeded in regard to Slovenian regulation. These regulations can be used as requirements for wastewater reuse and make treated wastewater an available source for the existing water supply.The study of conventional treatment was based on a flocculation with Al2(SO4)3·18H2O and adsorption on GAC. Membrane filtrations were studied on a pilot wastewater treatment plant: ultrafiltration (UF) and reverse osmosis (RO) units. The membranes used in this experiment were ceramic UF membrane and spiral wounded – polyethersulfone – RO membranes. The quality of the wastewater was improved by both methods and the specifications of a concentration limit for emission into water were confirmed. The disadvantage of GAC is that there is no possibility of any kind of selection, which is essential for recycling and re-use, while permeate coming from RO met the required regulation as well as requirements for reusing in washing process. However, the economical analyses showed that the membrane filtrations are more expensive compared to the GAC treatment process.
Article
Different membrane processes were experimented on at pilot scale to verify the possibility of reusing textile wastewater. The pilot plant used sand filtration and ultrafiltration (UF) as pre-treatments for a membrane process of nanofiltration (NF) or reverse osmosis (RO). UF was obtained by the installation of an innovative module designed on flat membranes operating under vacuum; the configuration of the NF and RO membranes was spiral wound. The efficiency of the various treatments in removing pollutants from textile wastewater from an activated sludge plant was tested on the reduced scale to optimize the industrial plant design. The UF module tested works at low operating pressure (that involves low energy costs) and guarantees a constant permeate (feed of the next membrane process of NF or RO). The RO permeate can be reused in the dyeing processes as demonstrated by many yarn dyeing tests on the industrial scale. NF does not reach the retention behaviour of RO (total hardness removal of 75% and > 90% for NF and RO, respectively). Nevertheless, a change in the freshwater treatment (at present an ion-exchange resin softening) downstream from the use of process water in the factory would decrease the secondary effluent salinity, so the design of the advanced purification industrial plant could reasonably foresee a NF treatment instead of RO, allowing a reduction of the costs.
Recycling Technology reaches Laundries, Laundry Clean
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Extensive analysis for the project Wastewater recycling for an Industrial Laundry-Use of new washing agent components, Thesis
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Extensive analysis on the development of a laundry wastewater recycling system, Thesis
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Waste Water Recycling Technology for Laundries
  • Scheibner
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Recycling Technology reaches Laundries
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