Patent ID: 7455773

Claim:
A chemical/biological wastewater treatment method for wastewater with dissolved and undissolved solids and nutrients comprising: a determining effluent discharge and disinfection limits for land application, open water discharge, and solids disposal requirements for a wastewater treatment plant's treated wastewater, b. flow-separating suspended solids in wastewater inflows for disposal to reduce particle size of suspended solids in separated wastewater inflows, c. deodorizing and conditioning the separated wastewater inflows by injecting into the wastewater inflows sulfur dioxide at a pH that generates sufficient sulfurous acid with free SO 2 to condition solids for disinfection, separation and to deodorize the separated wastewater inflows, d. holding the sulfur dioxide treated separated wastewater inflows in the same vessel into which the sulfur dioxide was injected, or a separate detention vessel, which captures any excess SO 2 emitted by the wastewater for reinjection, at a pH between approximately 1.5 and 4.5, depending upon dwell time, until a conditioned wastewater is produced where suspended solids agglomerate and dewater by shedding water upon separation and drying, dissolved solids and ammonia are sulfurous acid treated resulting in odor reduction and color changes of the conditioned solids and liquids, and required effluent disinfection occurs to meet disinfection limits, e. pH adjusting the conditioned wastewater to reduce the biocidal properties of any free SO 2 in the conditioned wastewater and provide the pH required for subsequent environmental biological treatment for reduction of the dissolved and suspended solids and ammonia to meet applicable land and open water discharge limits by either: i. land applying the conditioned wastewater for plant consumption in accordance with applicable land discharge limits, and/or ii. passing it through 1. aqueous vegetation for consumption, or 2. microbial reduction of the dissolved and suspended solids and ammonia for BOD compliance to produce water of sufficient quality to meet applicable open water discharge limits.