ALUMINUM HYDROXIDE COAGULANT RECOVERY FROM WATER/WASTEWATER TREATMENT SLUDGE

    公开(公告)号:US20190185335A1

    公开(公告)日:2019-06-20

    申请号:US15841533

    申请日:2017-12-14

    IPC分类号: C01F7/46 C02F11/14

    摘要: A method for recovery of aluminum hydroxide Al(OH)3 from an aluminum enriched water/wastewater treatment sludge is disclosed. The method includes the steps of: adding a hydrated lime slurry to the aluminum enriched water/wastewater treatment sludge to form an alkaline sludge; adding sodium carbonate Na2CO3 to the alkaline sludge to form a Na2CO3 treated sludge; forming a first supernatant from the Na2CO3 treated sludge of step b) containing NaAl(OH)4; introducing CO2 to the first supernatant to form a precipitate of Al(OH)3 and a second supernatant containing NaHCO3; and recycling at least a portion of the NaHCO3 from the second supernatant back to the alkaline sludge of step a).