Wastewater of dairy industries contains various high levels of organic contaminants due to wide range of products. In this assay, a combination of electro-oxidation and SBR reactor as a biological method were utilized to treat synthetic wastewater of dairy industries. First, electro-Fenton and electro-coagulation by Aluminum electrodes were established for pretreatment and after settling process, products were loaded to SBR reactor. Electrical current, time, pH, mixer speed, distance of electrodes and amount of hydrogen peroxide (for electro-Fenton) considered as effective parameters. After modification of electro-oxidation procedures, obtained effluent were sent to SBR section, aeration time were also optimized as an effective factor. Design of the experiments were accomplished by Design-Expert software which COD and turbidity were considered as responses. In pretreatment processes, electro-Fenton showed much more COD removal efficiency in comparison with electro-coagulation (90.5% vs 49.5%). However, effluent obtained from electro-coagulation were treated well in SBR and COD removal raised to 98.6% (30 mg/l) eventually. Furthermore, efficiency of turbidity removal were increased to more than 99% (from 870 to 7 NTU). Key Words: Electro-Fenton, Eelectro-Coagulation, SBR, RSM, COD, Turbidity.
