Evaluation of upgrading a full-scale activated sludge process integrated with floating biofilm carriers

• Published in: Water science and technology Vol. 70; no. 10; pp. 1594 - 1601
• Main Authors: Ge, Shijian, Zhu, Yunpeng, Qiu, Shuang, Yang, Xiong, Ma, Bin, Huang, Donghui, Peng, Yongzhen
• Format: Journal Article
• Language: English
• Published: London International Water Association 01.01.2014; IWA Publishing
• Subjects: Activated sludge; Activated sludge process; Aeration; Analysis methods; Applied sciences; Biofilms; Biological Oxygen Demand Analysis; Bioreactors - standards; Chemical oxygen demand; China; Control systems; Effluent standards; Evaluation; Exact sciences and technology; Feeding habits; Feeding rates; Floating; General purification processes; Impellers; Mineral nutrients; Natural water pollution; Nutrient removal; Phosphorus; Phosphorus - analysis; Pollution; Removal; Sewage - analysis; Sewerage works: sewers, sewage treatment plants, outfalls; Sludge; Submersibles; Waste Disposal, Fluid - economics; Waste Disposal, Fluid - instrumentation; Waste Disposal, Fluid - methods; Wastewater; Wastewater treatment; Wastewater treatment plants; Wastewaters; Water Pollutants, Chemical - chemistry; Water quality standards; Water treatment and pollution; China; China, People's Rep., Shandong Prov., Qingdao; Activated sludge; Water treatment; wastewater; Sewage treatment plant; Waste water; Biological purification; WWTP; Upgrading; Biofilm; Nutrient; ICEAS; Waste water purification; biological nutrient removal
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2014.370

This study evaluated the performance of a full-scale upgrade of an existing wastewater treatment plant (WWTP) with the intermittent cyclic extended aeration system (ICEAS), located in Qingdao, China. The ICEAS system was not able to meet effluent standards; therefore, a series of modifications and control strategies were applied as follows: (1) floating plastic carriers were added to the tank to aid biofilm formation; (2) operation parameters such as mixing and aeration time, feeding rate, and settling time were adjusted and controlled with a real-time control system; (3) a sludge return system and submersible water impellers were added; (4) the aeration system was also improved to circulate carriers and prevent clogging. The modified ICEAS system exhibited efficient organic and nutrient removal, with high removal efficiencies of chemical oxygen demand (89.57 ± 4.10%), NH4(+)-N (95.46 ± 3.80%), and total phosphorus (91.90 ± 4.36%). Moreover, an annual power reduction of 1.04 × 10(7) kW·h was realized as a result of these modifications.