Deep Purification Technology for High Hydrogen Sulfide, Ammonium and Phosphorus Content Sewage
For deep purification of sewage with high content of organic contaminants, hydrogen sulfide and hydrosulfides a technological scheme, including CW-1 and CW-2, using hydrogen peroxide has been developed. When higher values of ammonia nitrogen and phosphorus in the initial sewage this technological scheme may be supported by denitrifiers, bioreactors and sorption filters. It is possible to supply aluminum containing coagulant modified by activated carbon for phosphates removal.
1-fine mechanical purification grid, 2-vertical sand catcher, 3,6-mixing chamber, 4-circulation pump; 5-CW-1, 7-CW-2, 8-hydrogen peroxide preparation site; 9-coagulant preparation site; 10-mixer; 11-denitrifier; 12-bioreactor; 13-absorption filter, 14-sludge dewatering installation, 15-used air processing installation.
Introduction of peroxide in a mixing chamber of CW-1 and CW-2 is reasonable at reduced sulfur species concentrations more than 20 mg/liter. Repeated irrigation and waste water contact with biocoenosis biofilter and activated sludge in CW-1 aeropack reaction zone lead to deaeration of hydrogen sulfide, reagent and biochemical oxidation of sulfur compounds, biodegradation of organic impurities within BOD by 50-70% and partial denitrification process (10-15%). At CW-2 further adsorption and oxidation of the rest of the organic impurities as well as deep nitrification and denitrification processes of nitrogen-containing compounds occur. Foreseen in the technological scheme wastewater and sludge flows pumping from CW-1 into CW-2 provides a stable process of mineralization of sludge being displayed. Pumping from the CW-2 into CW-1 reduces the overload of biomass in CW-1.
The construction of the first stage of sewage treatment facilities in town Volsk, Saratov region is coming to its end. It’s capacity is 25 thousand m3/day with bioreactors and denitrifiers for deep wastewater advanced treatment.
