Singh Nitin Kumar, Kazmi Absar Ahmad, Starkl Markus
Environmental Engineering Group, Department of Civil Engineering, Indian Institute of Technology, Roorkee, 247667, India E-mail:
Competence Centre for Decision-Aid in Environmental Management, University of Natural Resources and Life Sciences/ DIB, Gregor Mendel Strasse 33, A-1180 Vienna, Austria.
Water Sci Technol. 2015;72(10):1840-50. doi: 10.2166/wst.2015.390.
The present study summarizes the start-up performance and lessons learned during the start-up and optimization of a pilot-scale plant employing integrated fixed film activated sludge (IFAS) process treating actual municipal wastewater. A comprehensive start-up was tailored and implemented to cater for all the challenges and problems associated with start-up. After attaining desired suspended biomass (2,000-3,000 mg/L) and sludge age (∼7 days), the average biological oxygen demand (BOD) and chemical oxygen demand (COD) removals were observed as 77.3 and 70.9%, respectively, at optimized conditions, i.e. hydraulic retention time (HRT), 6.9 h; return sludge rate, 160%. The influent concentrations of COD, BOD, total suspended solids, NH3-N, total nitrogen and total phosphorus were found to be in the range of 157-476 mg/L, 115-283 mg/L, 152-428 mg/L, 23.2-49.3 mg/L, 30.1-52 mg/L and 3.6-7.8 mg/L, respectively, and the minimum effluent concentrations were achieved as ∼49 mg/L, 23 mg/L, 35 mg/L, 2.2 mg/L, 3.4 mg/L and 2.8 mg/L, respectively, at optimum state. The present system was found effective in the removal of pathogenic bacteria (Escherichia coli, 79%; Salmonella spp., 97.5%; Shigella spp., 92.9%) as well as coliforms (total coliforms, 97.65%; faecal coliforms, 80.35%) without any disinfection unit. Moreover it was observed that the time required for the stabilization of the plant was approximately 3 weeks if other parameters (sludge age, HRT and dissolved oxygen) are set to optimized values.
本研究总结了采用一体化固定膜活性污泥（IFAS）工艺处理实际城市污水的中试规模工厂在启动和优化过程中的启动性能及经验教训。为应对与启动相关的所有挑战和问题，量身定制并实施了全面的启动方案。在达到所需的悬浮生物质浓度（2000 - 3000 mg/L）和污泥龄（约7天）后，在优化条件下，即水力停留时间（HRT）为6.9小时、污泥回流比为160%时，观察到平均生物需氧量（BOD）和化学需氧量（COD）去除率分别为77.3%和70.9%。发现进水的COD、BOD、总悬浮固体、NH₃-N、总氮和总磷浓度分别在157 - 476 mg/L、115 - 283 mg/L、152 - 428 mg/L、23.2 - 49.3 mg/L、30.1 - 52 mg/L和3.6 - 7.8 mg/L范围内，在最佳状态下，出水的最低浓度分别达到约49 mg/L、23 mg/L、35 mg/L、2.2 mg/L、3.4 mg/L和2.8 mg/L。本系统在没有任何消毒单元的情况下，对病原菌（大肠杆菌，去除率79%；沙门氏菌属，97.5%；志贺氏菌属，92.9%）以及大肠菌群（总大肠菌群，97.65%；粪大肠菌群，80.35%）的去除效果显著。此外，观察到如果将其他参数（污泥龄、HRT和溶解氧）设置为优化值，工厂达到稳定所需的时间约为3周。
