Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2007.1652.1655FarrokhiM. MesdaghiniaA.R. 122007712Monochlorophenols, particularly 3-monochlorophenol are resistant to biodegradation than many poly- chlorinated compound. The presence of chlorophenols in water has become a significant pollution problem. The biodegradation of 3-monochlorophenol was investigated by Anaerobic Baffled Reactor (ABR). A mixture of 3-MCP and glucose as synthetic wastewater was treated in a laboratory scale. The ABR reactor volume was 9 L and wastewater with different concentration of 3-MCP and hydraulic retention time of 2 days, was treated. The parameters that determined include COD, volatile suspended solids (VSS) and 3-MCP concentration. The initial sludge for reactor feeding was isolated from full scale ABR that was operated in an industrial complex. When the concentration of 3-MCP was 10 mg L1 and less, 3-MCP was able to be metabolized to mineral end products and the COD removal was about 90% and more. With increasing of 3-MCP concentration from 10 to 30 mg L1, the degradation of 3-MCP and COD removal were decreased significantly (p< 0.001). The variations of VSS in different concentration of 3-MCP was significant (p< 0.001). Increasing of COD to 2000 mg L1, improved the reactor performance and reduced the toxicity of 3-MCP. In the toxicity evaluation of 3-MCP on ABR biomass, the ratio of glucose/3-MCP is more important parameter than 3-MCP concentration.]]>APHA, AWWA, WPCF and WEF,199519th Edn.,AWWA,19904th Edn.,Bae, H.S., T. Yamagishi and Y. Suwa,2002148221227Barbara, R., S. Genthner, W.A. Price and P.H. Pritchard,19895614661471Baried, R.B.,19742165178Batstone, D.J., C. Picioreanu and M.C.M Van Loosdrecht,20064030993108Droste, R.L., K.J. Kennedy, J. Lu and M. Lentz,199838359367Farrokhi, M., A.R. Mesdaghinia, S. Naseri and A.R. Yazdanbakhsh,200332610Farrokhi, M., A.R. Mesdaghinia, S. Naseri and A.R. Yazdanbakhsh,200411219Geofeng, W., X. Hong and J. Mei,200466767Hendriksen, H.V. and B.K. Ahring,199124431436Milliken, C.E., G.P. Meire, J.E. Watts and K.R. Sowers,200470385392Mohn, W.W. and K.J. Kennedy,19925821312136Pringer, G. and S.K. Bhattacharya,19993326742682Weiland, P. and A. Rozzi,199124257277WHO,1987pp: 1-19pp: 1-19William, B.P. and. C.S. David,19993315591578Yao, R.S., M. Sun, C.L. Wang and S.S. Deng,20064030913098