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Ultrafiltration treatment of detergent solutions
Desalination 200 (2006) 274–276
Ultrafiltration treatment of detergent solutions Izabela Kowalska*, Katarzyna Majewska-Nowak, Małgorzata Kabsch-Korbutowicz Institute of Environmental Protection Engineering, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland email: [email protected] Received 26 October 2005; accepted 2 March 2006
1. Introduction Increasing water consumption for both industrial and domestic purposes has resulted in rapid deterioration in water quality. It is leading to a shortage of surface- and groundwater resources and to rise in costs of water and wastewater treatment. A rational water management should secure the purest water sources for direct human consumption and force to reuse process water for industrial application [1]. The environmental risk of detergent effluents associated with manufacture, use and disposal of these chemicals is of a great interest. The high and varied pollution loads of these effluents are mainly due to the residual products in the reactor, which have to be washed away in order to use the same facility for the manufacture of other products. The majority of detergent products reach the environment with domestic and industrial wastewater. Detergent effluents can cause significant environmental problems because detergent product and its ingredients can be relatively toxic to aquatic life. Membrane-based separation processes may be an attractive alternative to wastewater treatment *Corresponding author.
methods, which are based on physical–chemical processes, i.e., coagulation [2], foaming [3], advanced oxidation processes [4,5] and adsorption onto different types of activated carbons [6] and polyelectrolytes [7]. The processes — because of the selectivity of the membrane — create the possibility of recovering resources and process water as well as of reducing high organic load of the wastewater. 2. Experimental The ultrafiltration experiments of detergent model solutions and wastewater arising from detergent production were conducted. The anionic surfactant concentration in model solutions amounted to 600 g/m3, whereas detergent wastewater was characterized by much higher concentrations — about 1600 g/m3 and 50,000 g O2/m3 for anionic surfactants and chemical oxygen demand (COD-Cr), respectively. The preliminary tests for model solutions were performed with the use of flat-sheet polyethersulfone and polysulfone Intersep membranes (the cut-off of 5, 10 and 30 kDa) and flat Pellicon module with polyethersulfone membranes of the cut-off of 5 kDa. Effluents from detergent production were
Presented at EUROMEMBRANE 2006, 24–28 September 2006, Giardini Naxos, Italy. 0011-9164/06/$– See front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.desal.2006.03.343
I. Kowalska et al. / Desalination 200 (2006) 274–276
treated using capillary Koch/Romicon modules with polysulfone membranes of the cut-off of 2 and 5 kDa. Ultrafiltration experiments were run at the pressure range of 0.05–0.20 MPa. 3. Results and discussion The aim of the study was to evaluate the suitability of ultrafiltration for purification and concentration of model solutions as well as industrial wastewater containing detergents. The results obtained for model solutions during concentration processes indicate that polyethersulfone and polysulfone flat-sheet membranes (5 and 10 kDa) were characterized by good operation stability. The decrease in the permeate volume flux do not exceed 14% (in comparison to the permeate volume flux at the beginning of the process) for the 14-fold concentration factor. The 30 kDa membranes were more susceptible to fouling and therefore the drop in membrane permeability was more pronounced — 27% and 31% for PES and PS, respectively. Retention coefficient of anionic surfactants for all membranes tested was stable during concentration process and ranged from 75 (PS30) to 90% (PES5 and PS5). As well as concentration tests on Pellicon ultrafiltration module enabled efficient removal of anionic surfactants (about 90%) from model solutions. The next part of investigation was focused on evaluation of suitability of hollow fibre cartridge modules (PM2 and PM5) for the concentration process of industrial wastewater containing detergents. During effluent tests, the essential drop in membrane permeability for both modules was observed. The effluent volume flux exhibited only 50% and 20% of water volume flux for PM2 and PM5 module, respectively. Taking into account the results obtained, it can be concluded that treated wastewater showed strong affinity toward membrane material. The 5-fold and 2-fold decrease in membrane permeability (in comparison to water flux) observed for PM5 and PM2 module, respectively, was probably
275
caused by sorption of contaminates in the membrane pores. The applied modules during concentration processes were characterized by stable properties during long-term concentration process. The membrane permeability remained almost at constant level approaching 0.20–0.30 m3/m2·d (PM2 module) and 0.25–0.40 m3/m2·d (PM5 module) during concentration process. The permeate quality was also satisfactory in the course of wastewater concentration. The separation efficiency for both modules tested was similar: the modules yielded 65–85% reduction in COD-Cr value and over 95% retention of anionic surfactants. 4. Conclusions Taking into account the presented results, it can be stated that ultrafiltration — low pressure membrane process — is suitable for concentration of highly polluted effluents containing detergents. The high separation efficiency of anionic surfactant from model solutions as well as from detergent wastewater was observed. The applied modules were characterized by stable transport and separation properties. In the course of longterm effluent concentration, an essential drop in permeability was not observed and the permeate quality remained almost constant, although of systematic increase in pollution load of the concentrate. Acnowledgement The work was partly supported by the State Polish Committee for Scientific Research. Grant # T09 025 26. References [1]
A. Rozzi, F. Malpei, L. Bonomo and R. Bianchi, Textille wastewater reuse in northern Italy (COMO), Water Sci. Technol., 39 (1999) 121–128.
276 [2]
[3]
[4]
I. Kowalska et al. / Desalination 200 (2006) 274–276 A.H. Mahvi and B. Maleki, Removal of anionic surfactants in detergent wastewater by chemical coagulation, Pakistan J. Biol. Sci., 7 (2004) 2222– 2226. S. Boonyasuwat, S. Chavadej, P. Malakul and J.F. Scamehorn, Anionic and cationic surfactant recovery from water using a multistage foam fractionator, Chem. Eng. J., 93 (2003) 241–252. C.D. Adams and J.J. Kuzhikannil, Effect of UV/ H2O2 preoxidation on the aerobic biodegradation of quaternary amine surfactants, Water Res., 34 (2000) 668–672.
[5]
[6]
[7]
M. Kitis, C.D. Adams and G.T. Daigger, The effects of Fenton’s reagent pretreatment on the biodegradability of nonionic surfactans, Water Res., 33 (1999) 2561–2568. A.S. Sirotkin, L.Y. Koshkina and K.G. Ippolitov, The BAC process for treatment of waste water containing non-ionogenic synthetic surfactants, Water Res., 35 (2001) 3265–3271. E. Zielinska, J. Maslisska-Solich and E. Lekawska, Interaction of polyelectrolyte gels and surface active agents, Polish J. Environ. Studies, 8 (1999) 327–330.
Ultrafiltration treatment of detergent solutions Izabela Kowalska*, Katarzyna Majewska-Nowak, Małgorzata Kabsch-Korbutowicz Institute of Environmental Protection Engineering, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland email: [email protected] Received 26 October 2005; accepted 2 March 2006
1. Introduction Increasing water consumption for both industrial and domestic purposes has resulted in rapid deterioration in water quality. It is leading to a shortage of surface- and groundwater resources and to rise in costs of water and wastewater treatment. A rational water management should secure the purest water sources for direct human consumption and force to reuse process water for industrial application [1]. The environmental risk of detergent effluents associated with manufacture, use and disposal of these chemicals is of a great interest. The high and varied pollution loads of these effluents are mainly due to the residual products in the reactor, which have to be washed away in order to use the same facility for the manufacture of other products. The majority of detergent products reach the environment with domestic and industrial wastewater. Detergent effluents can cause significant environmental problems because detergent product and its ingredients can be relatively toxic to aquatic life. Membrane-based separation processes may be an attractive alternative to wastewater treatment *Corresponding author.
methods, which are based on physical–chemical processes, i.e., coagulation [2], foaming [3], advanced oxidation processes [4,5] and adsorption onto different types of activated carbons [6] and polyelectrolytes [7]. The processes — because of the selectivity of the membrane — create the possibility of recovering resources and process water as well as of reducing high organic load of the wastewater. 2. Experimental The ultrafiltration experiments of detergent model solutions and wastewater arising from detergent production were conducted. The anionic surfactant concentration in model solutions amounted to 600 g/m3, whereas detergent wastewater was characterized by much higher concentrations — about 1600 g/m3 and 50,000 g O2/m3 for anionic surfactants and chemical oxygen demand (COD-Cr), respectively. The preliminary tests for model solutions were performed with the use of flat-sheet polyethersulfone and polysulfone Intersep membranes (the cut-off of 5, 10 and 30 kDa) and flat Pellicon module with polyethersulfone membranes of the cut-off of 5 kDa. Effluents from detergent production were
Presented at EUROMEMBRANE 2006, 24–28 September 2006, Giardini Naxos, Italy. 0011-9164/06/$– See front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.desal.2006.03.343
I. Kowalska et al. / Desalination 200 (2006) 274–276
treated using capillary Koch/Romicon modules with polysulfone membranes of the cut-off of 2 and 5 kDa. Ultrafiltration experiments were run at the pressure range of 0.05–0.20 MPa. 3. Results and discussion The aim of the study was to evaluate the suitability of ultrafiltration for purification and concentration of model solutions as well as industrial wastewater containing detergents. The results obtained for model solutions during concentration processes indicate that polyethersulfone and polysulfone flat-sheet membranes (5 and 10 kDa) were characterized by good operation stability. The decrease in the permeate volume flux do not exceed 14% (in comparison to the permeate volume flux at the beginning of the process) for the 14-fold concentration factor. The 30 kDa membranes were more susceptible to fouling and therefore the drop in membrane permeability was more pronounced — 27% and 31% for PES and PS, respectively. Retention coefficient of anionic surfactants for all membranes tested was stable during concentration process and ranged from 75 (PS30) to 90% (PES5 and PS5). As well as concentration tests on Pellicon ultrafiltration module enabled efficient removal of anionic surfactants (about 90%) from model solutions. The next part of investigation was focused on evaluation of suitability of hollow fibre cartridge modules (PM2 and PM5) for the concentration process of industrial wastewater containing detergents. During effluent tests, the essential drop in membrane permeability for both modules was observed. The effluent volume flux exhibited only 50% and 20% of water volume flux for PM2 and PM5 module, respectively. Taking into account the results obtained, it can be concluded that treated wastewater showed strong affinity toward membrane material. The 5-fold and 2-fold decrease in membrane permeability (in comparison to water flux) observed for PM5 and PM2 module, respectively, was probably
275
caused by sorption of contaminates in the membrane pores. The applied modules during concentration processes were characterized by stable properties during long-term concentration process. The membrane permeability remained almost at constant level approaching 0.20–0.30 m3/m2·d (PM2 module) and 0.25–0.40 m3/m2·d (PM5 module) during concentration process. The permeate quality was also satisfactory in the course of wastewater concentration. The separation efficiency for both modules tested was similar: the modules yielded 65–85% reduction in COD-Cr value and over 95% retention of anionic surfactants. 4. Conclusions Taking into account the presented results, it can be stated that ultrafiltration — low pressure membrane process — is suitable for concentration of highly polluted effluents containing detergents. The high separation efficiency of anionic surfactant from model solutions as well as from detergent wastewater was observed. The applied modules were characterized by stable transport and separation properties. In the course of longterm effluent concentration, an essential drop in permeability was not observed and the permeate quality remained almost constant, although of systematic increase in pollution load of the concentrate. Acnowledgement The work was partly supported by the State Polish Committee for Scientific Research. Grant # T09 025 26. References [1]
A. Rozzi, F. Malpei, L. Bonomo and R. Bianchi, Textille wastewater reuse in northern Italy (COMO), Water Sci. Technol., 39 (1999) 121–128.
276 [2]
[3]
[4]
I. Kowalska et al. / Desalination 200 (2006) 274–276 A.H. Mahvi and B. Maleki, Removal of anionic surfactants in detergent wastewater by chemical coagulation, Pakistan J. Biol. Sci., 7 (2004) 2222– 2226. S. Boonyasuwat, S. Chavadej, P. Malakul and J.F. Scamehorn, Anionic and cationic surfactant recovery from water using a multistage foam fractionator, Chem. Eng. J., 93 (2003) 241–252. C.D. Adams and J.J. Kuzhikannil, Effect of UV/ H2O2 preoxidation on the aerobic biodegradation of quaternary amine surfactants, Water Res., 34 (2000) 668–672.
[5]
[6]
[7]
M. Kitis, C.D. Adams and G.T. Daigger, The effects of Fenton’s reagent pretreatment on the biodegradability of nonionic surfactans, Water Res., 33 (1999) 2561–2568. A.S. Sirotkin, L.Y. Koshkina and K.G. Ippolitov, The BAC process for treatment of waste water containing non-ionogenic synthetic surfactants, Water Res., 35 (2001) 3265–3271. E. Zielinska, J. Maslisska-Solich and E. Lekawska, Interaction of polyelectrolyte gels and surface active agents, Polish J. Environ. Studies, 8 (1999) 327–330.