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Novel Process for Treatment of Nitrate in Wastewater. Xiaoguang Meng, Ph.D., P.E. Center for Environmental Systems Stevens Institute of Technology Hoboken, NJ 07030, USA. Project Description.
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Novel Process for Treatment of Nitrate in Wastewater Xiaoguang Meng, Ph.D., P.E. Center for Environmental Systems Stevens Institute of Technology Hoboken, NJ 07030, USA
Project Description • Objective: Develop a novel process for rapid and complete treatment of nitrate in water. The process involves rapid removal of nitrate from water by nitrate-selective resin filters and complete conversion of nitrate to nitrogen gas with bio-regeneration of spent resin. • Problems of Existing Techniques: a) Regeneration of nitrate-laden anion exchange resins generated in water treatment with sodium chloride solution releases nitrate to the spent brine solution. Environmental agencies, such as California EPA, start to regulate discharge high saline solutions into environment; and b) Biological denitrification systems require large foot-print area and addition of nutrients and organic matter, and can not treat water containing biological toxins. • Advantages of the Proposed Process: a) small foot-print area and low capital and operation costs; b) no discharge of ammonium, nitrate, and nitrite; c) no use of salt or brine solution in regeneration of spent resins; and d) no addition of chemicals and organic matter in water treatment.
Preliminary Results Filtration removal of nitrate from refinery wastewater by new and bio-regenerated resins, empty bed contact time=10 min. Wastewater properties: nitrate=14-16 mg/L of NO3-N, salt content~1%. Recovery of nitrate removal capacity by an anion exchange resin during 20 cycles of batch exchange and bio-regeneration, compared to the capacity of new resin. The regeneration conditions were optimized after 13 cycles.