WASTEWATER TREATMENT SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a wastewater treatment system capable of highly efficiently decomposing a hardly biologically decomposable substance, enhanced in the methane gas ratio of excessive sludge in such a case that a methane fermentation tank is provided and capable of reducing a sludge treatment cost. SOLUTION: In a wastewater treatment system equipped with a biological treatment tank applying biological treatment to organic wastewater and a solubilizing treatment means for excess sludge discharged from the biological treatment tank, the solubilizing treatment means is constituted of a combination of a thermostatic biological treatment apparatus for converting excessive sludge to a low molecular substance in a temperature region of about 60-80 deg.C by lytic enzyme producing microorganisms or the like and an ozone treatment apparatus performing ozone treatment under an alkali condition.