Optimization of a compact on-site stormwater runoff treatment system: Process performance and reactor design. (February 2023)

• Record Type: Journal Article
• Authors: Qin, Yangjie; Zhou, Chuanting; Yu, Siqi; Pang, Hongjian; Guo, Jiaming; Wei, Jun; Wang, Libing; Xing, Yunxin; An, Ying; Zhou, Zhen
• Is Part Of: Chemosphere. Volume 315(2023)
• Publication Date: 2023-02
• Subjects: Breakthrough curve -- Coagulation -- Column model -- Ion exchange -- Stormwater runoff; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2023.137767
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Stormwater runoff has become a major anthropogenic urban pollution source that threatens water quality. In this study, coagulation-sedimentation, and ammonium ion exchange and regeneration (AIR) modules were coupled as a CAIR system to efficiently treat stormwater runoff. In the coagulation module, 99.3%, 91.7%, and 97.0% of turbidity, total phosphorus, and chemical oxygen demand could be removed at an optimized poly-aluminum ferric chloride dosage of 30 mg/L, and the continuous experiment confirmed that the full load mode was more suitable for its rapid start-up. In the AIR module, dynamic ammonium removal indicated that the breakthrough time decreased with the rising initial concentration and superficial velocity. The Modified Dose Response (MDR) model described the ammonium exchange behavior better than the Thomas and the Bohart-Adams models. Then, a design flow of the ion exchange reactor was constructed by correlating constants in the MDR model with engineering parameters, and the ion exchange reactor was designed for continuous operation of the CAIR system. The average concentrations of chemical oxygen demand, total phosphorus, ammonium nitrogen, and total nitrogen in the effluent of the CAIR system were 7.22 ± 2.26, 0.17 ± 0.05, 1.49 ± 0.01, and 1.62 ± 0.02 mg/L, respectively. The almost unchanged exchange capacity and physicochemical properties after the multicycle operation confirmed the durability of zeolite for ion exchange. Techno-economic analysis suggested that the CAIR system is practically promising for stormwater management with efficient pollutants removal, small footprint, and acceptable operating cost. Graphical abstract: Image 1 Highlights: A CAIR system was constructed by coagulation and NH4 + exchange-regeneration (AIR). The CAIR efficiently removed particles, COD and nutrients from stormwater runoff. A design flow for AIR was proposed based on a dynamic model of packed column. The durability of zeolite for ion exchange was confirmed by multicycle operation. CAIR proposed by the design flow is inspirable for space-saving stormwater management.