Synergistic effects of prokaryotes and oxidants in rapid sand filters treatment of groundwater versus surface water: Purification efficacy, stability and associated mechanisms. (May 2022)

• Record Type: Journal Article
• Authors: Yang, Haiyang; Tang, Xiaobin; Bai, Langming; Yang, Liu; Ding, Junwen; Chen, Rui; Du, Xing; Li, Guibai; Liang, Heng
• Is Part Of: Chemosphere. Volume 295(2022)
• Publication Date: 2022-05
• Subjects: KMnO4 amendment sand filtration -- Manganese removal -- Ammonium removal -- Water geochemistry -- Active manganese oxides -- Prokaryotic bacteria; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.133804
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Effective elimination of manganese (Mn) and ammonium (NH4 + -N) from drinking water is still challenging. Utilizing oxidants to improve the simultaneous removals of Mn and NH4 + -N from rapid sand filter (RSF) systems has been extensively studied. However, the prokaryotes containing in the water geochemical properties greatly affected the RSF performance. In this study, groundwater and micro-polluted surface water were used to compare with/without potassium permanganate (KMnO4 ) assistant on the contaminants removals and system stability. Results showed that KMnO4 reduced the start-up period of RSF for treating groundwater and surface water to 20 and 41 days, respectively, with excellent Mn removal rates (>97%). The relative abundance of efficient ammonia-oxidizing bacteria ( Nitrospira ) in RSF treated groundwater without KMnO4 was higher than that in RSFs treated micro-polluted surface water or with KMnO4, resulting in a higher NH4 + -N removal rate of the former (∼57%). Notably, KMnO4 and prokaryotes synergistically contributed to the amorphous structure, mixed phases (buserite, MnO2 and birnessite) and mixed-valence Mn system of active manganese oxides (MnOx), whose abundant oxygen vacancies and highly reactive Mn(III) favored the autocatalytic oxidation of Mn, while NH4 + -N removal relied more on bacteria actions. Additionally, prokaryotes enriched the bacterial community diversity, leading to a more stable RSF system when facing hydraulic loading shock. This paper provided new insight into the synergistic effect of KMnO4 and prokaryotes on Mn and NH4 + -N eliminations in RSFs and was helpful for practical applications. Graphical abstract: Image 1 Highlights: KMnO4 amended the RSF and reduced the start-up period by 43%–72%. Water geological properties significantly affected the RSF purification efficacy. Mn and NH4 + -N removals were dominated by MnOx and Nitrospira, respectively. KMnO4 and prokaryotes synergistically affected the characteristics of MnOx. A complex prokaryotic community conferred strong stability to the RSF.