Wastewater treatment from a Molasses based Distillery was a great challenge due to very high organic load.
As conventional practice, the spent wash was being treated through anaerobic process and followed by a two-stage aerobic process. The treated effluent quality was far below the standards and this conventional process required a lot of energy for operation. It also generated high amounts of sludge.
AEES along with WOG developed an advance treatment process to achieve reduction in power consumption and increase recovery of energy through treatment.
WOG installed and carried out an innovative solution for the distillery in Pakistan of a capacity 1500 m3/day. The effluent is treated through a two-stage anaerobic process followed by advance aerobic process.
The effluent is first treated across a slow rate anaerobic reactor to reduce COD from 100000 mg/l to 40000 mg/l. The anaerobically treated effluent is further treated across advance high rate anaerobic process called AHR (Anaerobic Hybrid Reactor). With this second stage anaerobic process, COD will be further removed by another 70% to reach 12000mg/l; and 19500Nm3 biogas generation which is equivalent to 10,300 liters per day fuel oil. In addition to the above the power consumption in aerobic treatment is also significantly reduced. The Sequential Batch reactor process is adopted for aerobic treatment. This has many advantages over conventional activated sludge process.