Abstract
Anaerobic reaction in addition to aerobic reaction were introduced into a biological treatment process for wastewater containing toxic chemicals such as phenol, thiocyanate and ammonium sulfate to study the performance of anaerobic reaction. Four experimental systems, i. e. continuous flow activated sludge prosess, continuous flow submerged filter (honeycomb tube) prosess, sequencing batch reactor activated sludge prosess and sequencing batch submerged filter prosess were compared.
TOC, phenol and thiocyanate were efficiently removed by all the systems, and particularly in the anaerobic process. Although denitrifying bacteria were noted in the sludge, little ammonium nitrogen could be removed by the washout of the nitrifying bacteria. Thiocyanate concentration up until 300 mg·l-1 showed no inhibition on the biodegradation of phenol.
Both the continuous flow reactors and the sequencing batch reactors discharged effluents with low TOC, the activated sludge process showed better performance for TOC removal than the submerged filter process.
