The performance of a dynamic vibratory membrane system for the recovery of usable water from soluble coffee processing wastewater has been investigated. Coffee wastewater is a complex food and beverage wastewater consisting of a variety of inorganic and organic constituents and dissolved and suspended solids. Manufacturing processes require high volumes of water, which leads to significant generation of wastewater. Effective design and scale-up of a recovery process are necessary to improve the sustainability of water draw for production. Rejections of COD, turbidity, and conductivity were observed to determine the purity of water recovered. A variety of membranes were initially screened for effective performance; a thin-film composite nanofiltration and a thin-film composite reverse osmosis membrane were selected for further studies. Process parameter studies for these membranes evaluated the effect of time, pressure, and vibration (shear). Steady-state flux was enhanced when vibration was introduced by factors of 4.5 and 1.6 when processing with the nanofiltration and reverse osmosis membranes, respectively. COD and turbidity rejection were above 97% for both the nanofiltration and reverse osmosis membranes in vibratory filtration. Conductivity rejection was 75 and 99% for the nanofiltration and reverse osmosis membranes, respectively, in vibratory filtration. The nanofiltration membrane was tested in a high-recovery simulation run and produced high flux at 85% total permeate recovery, indicating commercial-scale design is feasible.
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Environmental Chemistry
- Management, Monitoring, Policy and Law