|Technology||:||Membrane bioreactor (MBR) + reverse osmosis (RO)|
A leading Indian dairy required a wastewater treatment solution for their dairy production facility. The combined effluent for treatment consists of milk condensate COW water, process flush, clean-in-place (CIP) rinse, and water treatment plant backwash. The effluent had high total dissolved solids (TDS) and biochemical oxygen demand (BOD).
Based on the unique technical requirements, and general business objectives, SUEZ proposed MBR technology for the wastewater treatment plant using SUEZ’s ZeeWeed* 500D membranes. Process wastewater from the unit proceeds through a bar screen and collects in an equalization tank. The cooled wastewater from the heat exchanger is then fed into the bioreactor. The process aeration blowers provide air for the biological tank and ensure sufficient oxygen is available to maintain the biological processes in the tank. A permeate pump draws treated effluent through the pores of the membrane fibers and into the backpulse tank.
Part of MBR permeate is treated through a chlorine dioxide system before reuse. The remaining portion of MBR permeate is treated with activated carbon filters (ACFs) followed by RO. The filtered water from the RO feed pump is admitted to the membrane through a cartridge filter and is pressurized to the required pressure in a high pressure pump for RO membranes. The ACFs are provided upstream of the RO block and are the final barrier to controlling the organic matter entering the RO section. The RO permeate is then collected in an RO permeate tank and the reject is sent to the wastewater treatment plant where it undergoes disinfection via UV and chloride dioxide.
With the commissioning of this plant, the MBR permeate has BOD and total suspended solids (TSS) values of less than 5, and the RO permeate has TDS <50. The treated wastewater could be recycled for utilities 50.
*Trademark of SUEZ; may be registered in one or more countries.