title: Applying real-time control to enhance the performance of nitrogen removal in CAST system.
abstract: A bench-scale reactor(72 L) red with domestic sewage, was operated more than 3 months with three operation modes: traditional mode, modified mode and real-time control mode, so as to evaluate effects of the operation mode on the system performance and to develop a feasible control strategy. Results obtained from fixed-time control study indicate that the variations of the pH and oxidation-reduction potential(ORP) profiles can represent dynamic characteristics of system and the cycle sequences can be controlled and optimized by the control points on the pH and ORP profiles. A control strategy was, therefore, developed and applied to real-time control mode. Compared with traditional mode, the total nitrogen(TN) removal can be increased by approximately 16% in modified mode and a mean TN removal of 92% was achieved in real-time control mode. Moreover, approximately 12.5% aeration energy was saved in real-time control mode. The result of this study shows that the performance of nitrogen removal was enhanced in modified operation mode. Moreover, the real-time control made it possible to optimize process operation and save aeration energy.
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100022, China. wspfrd@hotmail.com
authors.forename: Shao-po
authors.initials: SP
authors.lastname: Wang
authors.forename: Yong-zhen
authors.initials: YZ
authors.lastname: Peng
authors.forename: Shu-ying
authors.initials: SY
authors.lastname: Wang
authors.forename: Shou-you
authors.initials: SY
authors.lastname: Gao
mesh_terms: D019149:Bioreactors; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000378:metabolism*; D010084:Oxidation-Reduction; D012722:Sewage / Q000032:analysis*; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D012722:Sewage; D009584:Nitrogen