Gravity-driven ceramic membrane (GDCM) filtration treating manganese-contaminated surface water: Effects of ozone(O3)-aided pre-coating and membrane pore size. (September 2021)

• Record Type: Journal Article
• Authors: Du, Xing; Liu, Yao; Ma, Rong; Xiao, Mengyao; Yang, Wupeng; Han, Xinyi; Luo, Yunlong; Wang, Zhihong; Liang, Heng
• Is Part Of: Chemosphere. Volume 279(2021)
• Publication Date: 2021-09
• Subjects: Gravity-driven ceramic membrane (GDCM) -- Water treatment -- Birnessite -- Cake layer -- Ceramic membrane -- Manganese removal; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.130603
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Achieving adequate manganese removal during water treatment is a challenging process. This study aimed to assess the effectiveness of gravity driven ceramic membrane (GDCM) filtration in the elimination of manganese from surface water. The impact of membrane pre-modification with birnessite and molecular weight cut-off on long-term water treatment efficiency was investigated by assessing filtration units with 300 kDa virgin membrane (300 kDa-blank), 300 kDa membrane pre-coated with manganese oxides (300 kDa-MnOx), and 15 kDa virgin membrane (15 kDa-blank). The results of 300 kDa-blank and 300 kDa-MnOx indicated that depositing manganese oxides (produced via ozone (O3 ) oxidation) prior to water treatment was conducive to ripening of cake layer which played a major role in Mn removal. Reducing membrane molecular cut-off from 300 to 15 kDa also significantly reduced permeate Mn concentration, achieving a removal efficiency of 75% at the end of the trial (highest of all the units). Relative to 300 kDa-blank, the greater manganese removals in the other two systems can be attributed to 1) the long hydraulic retention times resulting from the higher membrane resistance, and 2) the higher abundance of biologically produced Birnessite materials in the cake layers for manganese oxidation. Raman analysis and X-ray diffraction analysis showed that 15 kDa-blank achieved the highest level of Birnessite production and most cake materials featured a flower-like structure and relatively small size (as shown under a scanning electron microscope and Energy Dispersive X-Ray Spectroscopy element mapping analysis), suggesting a higher surface area for Mn oxidation. Graphical abstract: Image 1 Highlights: A ceramic membrane pre-coated with ozone (O3 )-aided MnOx was conducive to GDCM system start-up. GDMBR with a lower molecular weight cut-off membrane was benefited for Mn removal due to a longer HRT. Biodegradation was not a major pathway for Mn removal, but involved the production of birnessite. The flower-like birnessite surface enable to achieve the greater Mn removal.