Patent ID: 7867398

Claim:
A method for reducing the footprint of chemical/mechanical/biological wastewater treatment facilities employing sulfur dioxide for disinfection and chemical dewatering of solids in conjunction with an environmental biological treatment system comprising: a. injecting sufficient sulfur dioxide into the wastewater inflow streams to acidify and supersaturate the wastewater inflow streams with sufficient free SO 2 for disinfection, b. transferring the acidified supersaturated wastewater inflow streams into at least one enclosed reaction vessel or reaction zone to contain any surplus SO 2 , c. holding the acidified, supersaturated wastewater under positive pressure for a dwell period until the solids sufficiently agglomerate and separate from the liquid fraction, and disinfection of the wastewater solids and liquid fractions occurs forming a disinfected wastewater, d. applying negative pressure to remove after disinfection surplus SO 2 from the enclosed reaction vessel or reaction zone and supersaturated disinfected wastewater before draining for re-injection into incoming wastewater inflow streams to offset and reduce the amount of additional SO 2 required to maintain superstaturation conditions, e. filtering the solids from the sulfur dioxide-treated wastewater for solids disposal or capture to hold the separated solids until the desired chemical dewatering has occurred, and f. neutralizing the sulfur dioxide-treated wastewater land to pH adjust and inactivate any remaining SO 2 before land application, raising photo biomass, or groundwater recharge.