Biological Aerated Filter Applied to Advanced Treatment of Ammonia Nitrogen in Wastewater from Hair Products

Abstract

Wastewater from hair products was the industrial wastewater typically hard to treat with high concentration ammonia nitrogen (NH4+-N) and the low Carbon to Nitrogen (C/N) ratio. In this study ,a pilot-scale study was conducted on Biological Aerated Filter ( BAF) to deeply remove NH4+-N in wastewater from hair products, which aimed to provide technology support for hair products enterprises.The experiments showed that the optimal conditions of BAF was as following: the ratio of air to water was 19:1, the ammonia nitrogen volumetric load was 0.22 kgm3d-1, in this situation the removal efficiency of Chemical Oxygen Demand (CODcr) and NH4+-N were respectively from 25.0% to 32.5% and from 90.6% to 92.5%, the NH4+-N concentrations and CODcr in effluent were always under 12 mg/L and 100 mg/L respectively, which meet fully first class discharge standard requirement of Integrated wastewater discharge standard in china (GB8978-1996)(IWDSC). Moreover the experiment demonstrated that BAF returned to normal at the moment of 2.5 hours after the end of backwashing.