Raw sewage from a municipal treatment plant was polluted with 2,4-dichlorophenoxyacetic acid (2,4-D) (dose 100 mg/L) and purified in a lab. stand (chamber vol. 50 L) in presence of activated sludge at 15 degrees C, pH 6.5 under aeration (0 content 4 to 5 mg/L) and stirring (2 rpm). Three com. coagulating agents (0.1 to 1.0 mg/L) were addnl. used. The treated sewage was analyzed for BOD5, and COD, as well as for ammonia, nitrate(III) and nitrate(V) N, phosphate and 2,4-D contents. Fe sulfate was the most efficient coagulant in the 2,4-D removal. The addn. of coagulants resulted in decreasing the phosphate content but did not affect the nitrate N content in the treated sewage.