Processing urban and/or industrial wastewater, by performing biological hydrolysis in absence of oxygen by hydrolytic bacteria and acidogenes, and performing separation treatment of wastewater by coagulation/flocculation/floatation

摘要

The method comprises performing biological hydrolysis in absence of oxygen by hydrolytic bacteria and acidogenes. The biological hydrolysis is directly applied to wastewater without preliminary physicochemical treatment. A separation treatment of the wastewater is carried out at an exit of the biological hydrolysis by coagulation/flocculation/floatation. Fats and/or oils of concentrated residual muds obtained after treatment of separation are subjected to enzymatic hydrolysis. The mixture of hydrolyzed muds is recycled towards the biological hydrolysis after the enzymatic hydrolysis. The method comprises performing biological hydrolysis in absence of oxygen by hydrolytic bacteria and acidogenes. The biological hydrolysis is directly applied to wastewater to be treated without preliminary physicochemical treatment. A separation treatment of the wastewater is carried out at an exit of the biological hydrolysis by coagulation/flocculation/floatation. Fats and/or oils of concentrated residual muds obtained after treatment of separation are subjected to enzymatic hydrolysis. The mixture of hydrolyzed muds is recycled towards the biological hydrolysis after the enzymatic hydrolysis. The biological hydrolysis is carried out in a first agitated reactor (A), and ensures the solubilization of part of the fats and the oils and production of volatile fatty-acids. A pH of the reactor is maintained to be 4.5-7.5 by neutralization with alkalinity. A residence time for the biological hydrolysis is 8-36 hours. The concentrated muds at an exit of the separation treatment are contacting with an adapted enzyme or enzymes in a second agitated reactor. The residence time in the second reactor is 4-24 hours, and a pH in the second reactor is maintained to be 5.5-9. The effluent removed from concentrated muds is subjected to a step of mechanization in a mechanization reactor (B) supplemented by a step of biological dephosphatation in a dephosphatation reactor (C), optionally followed by a step of biological denitrification in a denitrification reactor (D), and optionally followed by an aerobic activated sludge step in an aerobic reactor (E). One of the reactors is supplemented by a final separator, and the concentrated muds outgoing the final separator are recycled at an entrance of the biological hydrolysis and/or the enzymatic hydrolysis. An independent claim is included for an installation for processing urban and/or industrial wastewater containing fats and/or oils.