MBR/RO PRODUCES REUSE WATER FOR A FOOD PROCESSING FACILITY AND TO COOL THE FACILITY LOWERING OVERALL ELECTRICAL USAGE

摘要

A vegetable processing facility in Kobe, Japan, washes, peels and packages vegetables fordistribution. Its operation produces an average of 53,000 gpd of wastewater. The vegetablewashing produces a relatively low BOD (200 mg/l) waste but the peelings are pressed to dewaterand produce a very high BOD (2,300 mg/l) waste. As a result, the blended wastewater wasfound to be high in BOD (1,250 mg/l), COD (650 mg/l) and TSS (300 mg/l) resulting in achallenging high viscosity, high organic wastewater. Due to the cost of discharge to the localmunicipality, the company explored installing its own wastewater treatment facility and reusingthe wastewater.In 2007, a Membrane Bioreactor (MBR) system was installed at the facility. The MBR wasselected due to its small footprint, consistent high quality effluent, and low requirement foroperator attention. The MBR system provided an economical way for the facility to personallydeal with their wastewater. The system has produced consistent high quality effluent sincestartup with no process or membrane issues to report.After the successful implementation of the MBR system, ways to reuse the MBR effluent werethen explored. Reuse required an RO system to further treat the MBR effluent to reduce its TDS,and was installed in 2009. RO was selected because of its consistent quality and lowrequirement for operator attention. The RO permeate is utilized back in the processing facility.In addition to direct reuse, a novel approach was selected to recycle some of the wastewater. Inthe warmer months when air conditioning is required in their processing facility, they also usesome RO permeate to cool the facility. During this time, the wastewater is sprayed on the metalroof of their processing facility to reduce the temperature in the building. This facility showshow membranes can effectively be used to not only protect the environment but also make thecompany more profitable.