Two-stage anaerobic/aerobic wastewater treatment process

摘要

A two-stage process for purifying wastewater includes the steps of biophysical anaerobic treatment (12) to remove the majority of the COD, followed by biophysical aerobic treatment (28) to further purify the wastewater. A powdered adsorbent, preferably powdered activated carbon, is used with biological solids in each treatment step. Excess biophysical solids from the aerobic step (28) are transferred to the anaerobic step (12) for digestion. Fresh powdered adsorbent is added to the aerobic treatment step (28) to compensate for that transferred to the anaerobic treatment step. Solids concentration in the anaerobic step (12) is controlled by wasting solids to disposal.