Study on backwash wastewater from rapid sand-filter by monolith ceramic membrane

To verify the feasibility of membrane micro-filtration process to treat the sand-filter backwash wastewater and the sediment sludge withdrawn from the coagulation–flocculation–settling tank, a multi-lumen monolith ceramic membrane module was applied in a test pilot plant. The ceramic membrane filtration was operated very stably at the filtration flux of 4 m/day when the sand-filter backwash wastewater was fed. The membrane filtration was also operated very stably at the flux of 2 m/day when the mixture of the sand-filter backwash wastewater and the sediment sludge was fed. The level of these substances in the membrane filtrate was very low and met drinking water standards.