Аннотация:A combined biological and chemical treatment of high strength (total COD up to 20 g/l), strong nitrogenous (total N up to 1 g/l) and phosphoric (total P up to 0.4 g/l) starch industry wastewater was investigated at lab scale level. As a principal step for COD elimination, a UASB reactor performance was investigated at 30 oC. Under hydraulic retention times (HRT) of around 1 day, when the organic loading rates (OLR) were higher than 15 g COD/l/d, the total COD removal varied between 77-93% giving the effluents with COD/N ratio of 4-5 approaching to the requirements of subsequent denitrification. The activated sludge reactor operating in aerobic-anoxic regime (HRT of around 4 days, duration of aerobic and anoxic phases 30 min each) was able to remove up to 90% of total nitrogen and up to 64% of total COD from the anaerobic effluents under 17-20 oC. The coagulation experiments with Fe(III) showed that 1.4 mg of resting hardly biodegradable COD and 0.5 mg phosphate (as P) could be removed from the aerobic effluents by each mg of iron added.