TREATMENT USING FIXED FILM PROCESSES AND BALLASTED SETTLING
A system and method is provided for water and wastewater treatment. The system comprises a fixed film biological process and a ballasted flocculation process.
1 . A system for treating wastewater comprising:
a fixed film reactor fluidly connected to a source of wastewater and configured to provide a fixed film effluent;
a source of ballast fluidly connected to the fixed film effluent and configured to provide a ballasted effluent; and
a clarifier fluidly connected to the ballasted effluent, the clarifier comprising a treated effluent outlet and a ballasted solids outlet and configured to separate a treated effluent from a ballasted solids.
2 . The system of claim 1 , further comprising a source of flocculant fluidly connected to the ballasted effluent.
3 . The system of claim 1 , further comprising a source of coagulant fluidly connected to the fixed film effluent and configured to provide a coagulated effluent.
4 . The system of claim 1 , wherein the fixed film reactor comprises at least one of a moving bed bioreactor, a trickling filter, and a rotating biological contactor.
5 . The system of claim 1 , wherein the fixed film effluent comprises about 50 mg/l to about 300 mg/l of biological solids.
6 . The system of claim 1 , wherein the ballast comprises magnetite.
7 . The system of claim 1 , wherein the system is configured to treat between about 200 gallons per day per square foot of a surface area of the clarifier to about 6,000 gallons per day per square foot of the surface area of the clarifier.
8 . The system of claim 3 , wherein the ballasted solids outlet of the clarifier is fluidly connected to at least one of the coagulated effluent and the fixed film reactor.
9 . The system of claim 8 , further comprising a ballast recovery system positioned downstream of the ballasted solids outlet of the clarifier and upstream of at least one of the source of ballast and the fixed film reactor.
10 .- 20 . (canceled)