- Email: [email protected]
Effectiveness of MBR in pre-disinfection and AOX removal for hospital wastewater treatment
Abstracts / Journal of Biotechnology 136S (2008) S647–S677
S659
References
VII4-P-026
Hamoda, M.F., Al-Attar, I.M.S., 1995. Effects of high sodium chloride concentrations on activated sludge treatment. Water Science and Technology 31, 61–72. Lefebvre, Olivier, Moletta, René, 2006. Treatment of organic pollution in industrial saline wastewater: a literature review. Water Research 40, 3671–3682. Panswad, Thongchai, Anan, Chadarut, 1999. Impact of high chloride wastewater on an anaerobic/anoxic/aerobic process with and without inoculation of chloride acclimated seeds. Water Research 33, 1165–1172.
Effectiveness of MBR in pre-disinfection and AOX removal for hospital wastewater treatment
doi:10.1016/j.jbiotec.2008.07.1526 VII4-P-025 Identification and reduction of toxic products of chlorobenzene treatment by a combined UV-biofilter process Can Wang ∗ , Hong-Ying Hu, Jin-ying Xi Environmental Simulation and Pollution Control State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing, China E-mail address: [email protected] (C. Wang). In order to evaluate the ecological security and feasibility of an integrated UV-biofilter process to treat gaseous chlorobenzene, the chemical composition and the toxicity of photodegradation products had been investigated in this study. The experimental results showed the UV photodegradation process would give birth to products having significant acute toxicity and genotoxicity. The acute toxicity and genotoxicity could reach as high as 0.042 mg Zn2+ /mg TOC and 0.76 g 4-NQO/mg TOC, respectively. Further analysis of the products using three-dimensional fluorescence spectrum and GC/MS techniques indicated that the main products of chlorobenzene photodegradation included hydrochloride, acetic acid, formate acid, phenol and chlorophenol. And phenol was the most significant product since about 64% of removed chlorobenzene was transferred to phenol. In the integrated process, the toxic products after UV photodegradation stage could be removed by the following biofilter. The acute toxicity reduced to 0.005 mg Zn2+ /mg TOC. And the genotoxicity reduced to 0.16 g 4NQO/mg TOC. Finally, the integrated UV-biofilter process has been proven to be more ecological safe and less infective compared with standalone UV process or biofiltration process. References Cantavenera, M.J., Cantazaro, I., Loddo, V., Palmisano, L., Sciandrello, G., 2007. Photocatalytic degradation of paraquat and genotoxicity of its intermediate products. Journal of Photochemistry and Photobiology A: Chemistry 185, 277–282. Chen, W., Westerhoff, P., Leenheer, J.A., Booksh, K., 2003. Fluorescence excitation—Emission matrix regional integration to quantify spectra for dissolved organic matter. Environmental Science and Technology 37 (24), 5701–5710. Moussavi, G., Mohseni, Madjid, 2007. Using UV pretreatment to enhance biofiltration of mixtures of aromatic VOCs. Journal of Hazardous Materials 144 (1–2), 59–66. Wang, L.S., Hu, H.Y., Wang, C., 2007. Effect of ammonia nitrogen and dissolved organic matter fractions on the genotoxicity of wastewater effluent during chlorine disinfection. Environmental Science and Technology 41 (1), 160–165. Wang, C., Xi, J.Y., Hu, H.Y. A novel integrated UV-biofilter system to treat high concentration of gaseous chlorobenzene. Chinese Science Bulletin, in press.
doi:10.1016/j.jbiotec.2008.07.1527
Yingxue Sun 1,2,∗ , Ping Gu 1 , Keli Wang 1 , Feng Zhang 1 1
School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China 2 Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China E-mail address: [email protected] (Y. Sun).
Hospital wastewater with its high content of pathogens poses a grave problem for the community. Also, it is considered as an important source of Adsorbable organic halogens (AOX) in municipal wastewater (Kummerer et al., 1998), some of which are toxic for aquatic organisms and are persistent environmental contaminants (Emmanuel et al., 2004). The aim of this study was to investigate the pre-disinfection characteristics of membrane bioreactor (MBR) and its biodegradation for AOX in hospital wastewater treatment process, and then the contribution of MBR for decreasing the bio-toxicity of hospital wastewater was evaluated. The hospital wastewater samples were obtained from a general hospital occupying a separated effluent treatment plant using MBR process. Polyvinylidene fluoride (nominal pore size was 0.2 m) membrane was used in this MBR. The principal conventional qualities of these water samples were analyzed in accordance with standard methods (APHA, 1998). The concentration of AOX was measured by IDCAnalysystem AOX-3 (Germany). The results show that the removal rates of total bacteria and fecal coliform by this MBR are 2.0–3.1 log and 2.8–4.0 log, respectively, which serves as a remarkable predisinfection unit. The removal of AOX in the hospital wastewater is 63.6% after treatment by the MBR, and the contribution of membrane rejection accounts for 14.5%. To meet the requirement for indicative microorganism (fecal coliform) in the Discharge Standard of Water Pollutants for Medical Organization (GB18466-2005), sodium hypochlorite was used as disinfectant to inactivate the residual indicator bacteria in the effluent from MBR. When controlling the concentration of available chlorine is 0.8 mg/L, the fecal coliform can be completely inactivated with contact time of 1.0 h. Meanwhile, the generation of AOX 102.5 g/L, and the corresponding bio-toxicity by acute toxicity test with Daphnia magna is 8.96 g/L (K2 Cr2 O7 ), which is much lower than that generated in the chlorinated hospital raw wastewater. References APHA, AWWA, WEF, 1998. Standard Methods for the Examination of Water and Wastewater. 20th ed., APHA/AWWA/WEF. Washington, DC. Emmanuel, E., Keck, G., Blanchard, J.M., Vermande, P., Perrodin, Y., 2004. Toxicological effects of disinfections using sodium hypochlorite on aquatic organisms and its contribution to AOX formation in hospital wastewater. Environ. Int. 30, 891–900. Kummerer, K., Erbe, T., Gartiser, S., Brinker, L., 1998. AOX—Emissions from hospitals into municipal waste water. Chemosphere 36, 2437–2445.
doi:10.1016/j.jbiotec.2008.07.1528
S659
References
VII4-P-026
Hamoda, M.F., Al-Attar, I.M.S., 1995. Effects of high sodium chloride concentrations on activated sludge treatment. Water Science and Technology 31, 61–72. Lefebvre, Olivier, Moletta, René, 2006. Treatment of organic pollution in industrial saline wastewater: a literature review. Water Research 40, 3671–3682. Panswad, Thongchai, Anan, Chadarut, 1999. Impact of high chloride wastewater on an anaerobic/anoxic/aerobic process with and without inoculation of chloride acclimated seeds. Water Research 33, 1165–1172.
Effectiveness of MBR in pre-disinfection and AOX removal for hospital wastewater treatment
doi:10.1016/j.jbiotec.2008.07.1526 VII4-P-025 Identification and reduction of toxic products of chlorobenzene treatment by a combined UV-biofilter process Can Wang ∗ , Hong-Ying Hu, Jin-ying Xi Environmental Simulation and Pollution Control State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing, China E-mail address: [email protected] (C. Wang). In order to evaluate the ecological security and feasibility of an integrated UV-biofilter process to treat gaseous chlorobenzene, the chemical composition and the toxicity of photodegradation products had been investigated in this study. The experimental results showed the UV photodegradation process would give birth to products having significant acute toxicity and genotoxicity. The acute toxicity and genotoxicity could reach as high as 0.042 mg Zn2+ /mg TOC and 0.76 g 4-NQO/mg TOC, respectively. Further analysis of the products using three-dimensional fluorescence spectrum and GC/MS techniques indicated that the main products of chlorobenzene photodegradation included hydrochloride, acetic acid, formate acid, phenol and chlorophenol. And phenol was the most significant product since about 64% of removed chlorobenzene was transferred to phenol. In the integrated process, the toxic products after UV photodegradation stage could be removed by the following biofilter. The acute toxicity reduced to 0.005 mg Zn2+ /mg TOC. And the genotoxicity reduced to 0.16 g 4NQO/mg TOC. Finally, the integrated UV-biofilter process has been proven to be more ecological safe and less infective compared with standalone UV process or biofiltration process. References Cantavenera, M.J., Cantazaro, I., Loddo, V., Palmisano, L., Sciandrello, G., 2007. Photocatalytic degradation of paraquat and genotoxicity of its intermediate products. Journal of Photochemistry and Photobiology A: Chemistry 185, 277–282. Chen, W., Westerhoff, P., Leenheer, J.A., Booksh, K., 2003. Fluorescence excitation—Emission matrix regional integration to quantify spectra for dissolved organic matter. Environmental Science and Technology 37 (24), 5701–5710. Moussavi, G., Mohseni, Madjid, 2007. Using UV pretreatment to enhance biofiltration of mixtures of aromatic VOCs. Journal of Hazardous Materials 144 (1–2), 59–66. Wang, L.S., Hu, H.Y., Wang, C., 2007. Effect of ammonia nitrogen and dissolved organic matter fractions on the genotoxicity of wastewater effluent during chlorine disinfection. Environmental Science and Technology 41 (1), 160–165. Wang, C., Xi, J.Y., Hu, H.Y. A novel integrated UV-biofilter system to treat high concentration of gaseous chlorobenzene. Chinese Science Bulletin, in press.
doi:10.1016/j.jbiotec.2008.07.1527
Yingxue Sun 1,2,∗ , Ping Gu 1 , Keli Wang 1 , Feng Zhang 1 1
School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China 2 Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China E-mail address: [email protected] (Y. Sun).
Hospital wastewater with its high content of pathogens poses a grave problem for the community. Also, it is considered as an important source of Adsorbable organic halogens (AOX) in municipal wastewater (Kummerer et al., 1998), some of which are toxic for aquatic organisms and are persistent environmental contaminants (Emmanuel et al., 2004). The aim of this study was to investigate the pre-disinfection characteristics of membrane bioreactor (MBR) and its biodegradation for AOX in hospital wastewater treatment process, and then the contribution of MBR for decreasing the bio-toxicity of hospital wastewater was evaluated. The hospital wastewater samples were obtained from a general hospital occupying a separated effluent treatment plant using MBR process. Polyvinylidene fluoride (nominal pore size was 0.2 m) membrane was used in this MBR. The principal conventional qualities of these water samples were analyzed in accordance with standard methods (APHA, 1998). The concentration of AOX was measured by IDCAnalysystem AOX-3 (Germany). The results show that the removal rates of total bacteria and fecal coliform by this MBR are 2.0–3.1 log and 2.8–4.0 log, respectively, which serves as a remarkable predisinfection unit. The removal of AOX in the hospital wastewater is 63.6% after treatment by the MBR, and the contribution of membrane rejection accounts for 14.5%. To meet the requirement for indicative microorganism (fecal coliform) in the Discharge Standard of Water Pollutants for Medical Organization (GB18466-2005), sodium hypochlorite was used as disinfectant to inactivate the residual indicator bacteria in the effluent from MBR. When controlling the concentration of available chlorine is 0.8 mg/L, the fecal coliform can be completely inactivated with contact time of 1.0 h. Meanwhile, the generation of AOX 102.5 g/L, and the corresponding bio-toxicity by acute toxicity test with Daphnia magna is 8.96 g/L (K2 Cr2 O7 ), which is much lower than that generated in the chlorinated hospital raw wastewater. References APHA, AWWA, WEF, 1998. Standard Methods for the Examination of Water and Wastewater. 20th ed., APHA/AWWA/WEF. Washington, DC. Emmanuel, E., Keck, G., Blanchard, J.M., Vermande, P., Perrodin, Y., 2004. Toxicological effects of disinfections using sodium hypochlorite on aquatic organisms and its contribution to AOX formation in hospital wastewater. Environ. Int. 30, 891–900. Kummerer, K., Erbe, T., Gartiser, S., Brinker, L., 1998. AOX—Emissions from hospitals into municipal waste water. Chemosphere 36, 2437–2445.
doi:10.1016/j.jbiotec.2008.07.1528