Development of pilot scale nanofiltration system for yeast industry wastewater treatment

The treatment of the yeast industry wastewater was investigated by nanofiltration (nf) membrane process on apilot scale. two wastewaters were used as feed: (i) dilute wastewater with cod 2000 mg/l and (ii) concentratewastewater with cod 8000 mg/l. the permeate flux, cod retention, color and electrical conductivity (ec) removalwere evaluated in relation to trans-membrane pressure and long-term filtration. a linear growth in permeate fluxwas found with increasing in trans-membrane pressure for wastewaters. in addition, the cod retention, color andec removal increased with trans-membrane pressure enhancement. the results obtained from the long-termnanofiltration of dilute wastewater indicated that the permeate flux decreased from 2300 l/day to 1250 l/day andcod retention increased from 86% to 92%. the quality of the permeate in term of cod is lower than the dischargestandard in river (200 mg/l). thus, this process is useful for treatment of wastewaters produced by yeast industry.