Membrane process treatment for greywater recycling: investigations on direct tubular nanofiltration

摘要

On-site greywater recycling and reuse is one of the main ways to reduce potable waternrequirement in urban areas. Direct membrane filtration is a promising technology to recyclengreywater on-site. This study aimed at selecting a tubular nanofiltration (NF) membrane andnits operating conditions in order to treat and reuse greywater in buildings. To do so, a syntheticngreywater (SGW) was reconstituted in order to conduct experiments on a reproducible effluent.nThen, three PCI NF membranes (AFC30, AFC40 and AFC80) having distinct molecular weightncut-offs were tested to recycle this SGW with a constant concentration at 258C at twondifferent transmembrane pressures (20 and 35 bar). The best results were obtained withnAFC80 at 35 bar: the flux was close to 50 Lm22 h21, retentions of 95% for chemical oxygenndemand and anionic surfactants were observed, and no Enterococcus were detected in thenpermeate. The performances of AFC80 were also evaluated on a real greywater: fluxes andnretentions were similar to those observed on SGW. These results demonstrate theneffectiveness of direct nanofiltration to recycle and reuse greywater.