Effects of Colloidal Organic Substrate on Nitrification in Biofilms
胶体态有机物对生物膜硝化过程的影响

The effects of colloidal and soluble organic substrates on nitrification in biofilms were investigated in biological aerated filters. The results showed that the hydrolysis process of colloidal organic matter took place rapidly, which could not be the limiting step of its oxidation in the biofilm. Some 70% organic matter oxidation was accomplished at the 40 cm at the bottom of the both filters, while the increase of organic matter in the influent resulted in the displacement of nitrification from the bottom to the upper part of filter bed. It was observed that the greater reduction on nitrification was caused by colloidal organic matter than by soluble organics at the same COD concentration.