ANAEROBIC TREATMENT OF INDUSTRIAL WASTEWATER

摘要

Feed water is processed in an anaerobic digester. A solid-liquid separation device, for example a sludge screw thickener, treats a stream drawn from the digester in a recirculation loop. The solids portion is returned to the digester to increase the solids retention time and the TSS concentration in the digester. A liquid portion with less than 5% of the solids in the stream is removed and optionally treated further. The flow rate to the solid-liquid separation device is preferably greater than the influent flow rate. The solid-liquid separation device may receive digestate at a TSS concentration of 4% or more and return a solids portion having a TSS concentration of over 10%. The feed water is preferably one or more industrial waste streams having a COD concentration of 20,000 to 50,000 mg/L and a TSS concentration from 1-5%. The organic loading rate may be 10-12 kg/COD/m3/day.

主权项

1. A method for treating wastewater comprising steps of,
a) feeding an influent at a flow rate Q to an anaerobic digester; b) feeding a mixture from the anaerobic digester a flow rate of Q or more to a solid liquid separation device; c) separating the mixture into a liquid portion and a solids portion; and, d) returning at least most of the solids portion to the anaerobic digester.