DEGRADATION OF AROMATIC COMPOUNDS USING MOVING BED BIOFILM REACTORS

For biological treatment of water, there are many di fferent biofilm systems in use, examples of them aretrickling filters, rotating biological contactors, fixed media submerged biofilt ers, granular media biofilt ersand fluidiz ed bed reactors. they all have their advantages and disadvantages. hence, the moving bedbiofilm reactor process was developed in norway in the late 1980s and early 1990s to adopt the bestfeatures of the activated sludge process as well as those of the biofilt er processes, without includin g theworst. two cylindrical moving bed biofilm reactors were used in this study working in upflow streamconditions. experiments have been done in aero bic batch flow regime, laboratory experiments wereconducted at room tempe ratur e (23-28°c) and synthetic wastewater comprising a composition of phenoland hydroquin onc in each reactor as the main organic constituents, plu s balanced nutrients and alkalinitywere used to feed the reactor. the ratio of influent to effluent cod was determin ed at different retentiontimes. the result s indicated that the removal effic iency of each selected compound is affected by thedetent ion time, at low phenol and hydroquinone concentration (from 700 to 1000 mg/l) maximumremoval efficiency (over 80%) was obtained. by further increasing in cod loading rate up to 3000 mg/l,a decrease in cod removal rate was occurred, in the reacto r containing pyrogallol in cod of 1500 mg/l,the removal rate decre ased to lo percent because of its toxicity for microorganisms,