title: Effect of the mixing ratio during co-treatment of landfill leachate and sewage with a combined stripping and reversed A²/O process.
abstract: In this study, pilot-scale tests were conducted to evaluate the effect of volumetric mixing ratio of landfill leachate to sewage on the performance of the combined ammonia stripping and reversed anaerobic/anoxic/oxic (A(2)/O) process for co-treatment of landfill leachate and municipal sewage. Stripping, as pre-treatment, could significantly remove ammonia nitrogen (NH3-N) and total nitrogen (TN) by 55% and 52%, respectively. Moreover, chemical oxygen demand (COD) was slightly reduced by 6.8%, and little total phosphorus (TP) was removed. The subsequent reversed A(2)/O process appeared to be highly influenced by the volumetric mixing ratio of leachate to sewage. Typically, the effluent COD, NH3-N, TN and TP increased with the increasing ratio from 1:30 to 1:15, namely, the increasing fraction of leachate. Over the all tested mixing ratio range, the effluent COD and NH3-N were satisfied with the primary B standards of Chinese Discharge Standard of Pollutants for municipal waste water treatment plant (GB18918-2002). The standards different from the primary A standards for water reuse are used for discharge into the most surface water bodies in China. However, TN and TP would exceed the primary B standard levels at a mixing ratio of 1:15 or greater. These findings suggest that an appropriate volumetric mixing ratio should be carefully selected to ensure the performance of the reversed A(2)/O process.
authors.affiliation: a Key Eco-Environment of Laboratory of Three Gorges Reservoir Region Ministry of Education , Chongqing University , Chongqing 400045 , People's Republic of China.
authors.forename: Xiao-lan
authors.initials: XL
authors.lastname: Zeng
authors.forename: Wen-chuan
authors.initials: WC
authors.lastname: Ding
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhang
authors.forename: Peng
authors.initials: P
authors.lastname: Wan
authors.forename: Yang
authors.initials: Y
authors.lastname: Deng
authors.forename: Shuangshuang
authors.initials: S
authors.lastname: Wang
mesh_terms: D000332:Aerobiosis; D000641:Ammonia / Q000737:chemistry / Q000302:isolation & purification; D000693:Anaerobiosis; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D012722:Sewage; D014874:Water Pollutants, Chemical; D000641:Ammonia
keywords: ammonia stripping; landfill leachate; reversed A2/O; sewage; volumetric mixing ratio