In this study, nanofiltration (NF) and reverse osmosis (RO) were used in laboratory scale to concentrate As containing wastewater. Cross flow membrane filtration apparatus was applied in batch mode with recycling the retentate. Then the retentate of membrane filtration was treated with lime (Ca(OH)(2)) and sulfur hydrogen (H2S) to help the precipitation for producing clean water and a low volume, highly concentrated As waste.