Molecular transformations of dissolved organic matter during UV/O3-assisted membrane filtration of UASB-treated real textile wastewater

TY - JOUR

T1 - Molecular transformations of dissolved organic matter during UV/O3-assisted membrane filtration of UASB-treated real textile wastewater

AU - Mehmood, Ch Tahir

AU - Lu, Chuyue

AU - Maqbool, Tahir

AU - Xiao, Yeyuan

AU - Zhong, Ziyi

PY - 2022/11/1

Y1 - 2022/11/1

N2 - A ceramic membrane reactor (CMR) integrated with in-situ UV/O3 was assessed for post-treatment of the effluent out of an up-flow anaerobic sludge blanket (UASB) reactor treating real textile wastewater, focusing on the transformation of dissolved organic matter (DOM). Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) revealed the transformation of heteroatomic DOM containing S, N or both to simpler DOM containing mainly C, H, and O atoms. The decreased N contents in products (N/C = 0.0249) compared to precursors (N/C = 0.0311) and the higher O/C ratios in the N-containing products suggest the removal of R–NH2 groups accompanying DOM oxidation. While, S-containing compounds in the products had lower O/C and H/C ratios, suggesting a reduced state and the transformation of R–SO3 to R–S–R. H-abstraction and OH addition were identified as the primary oxidation mechanisms, thus enhancing the dominance of highly unsaturated and phenolic DOM in the effluent (70.3%) compared to the feed (56.6%). The double bond equivalent (DBE) was also increased by 26% in the effluent compared to the feed and by 33% in products compared to precursors. These findings help understand the DOM transformation in UV/O3-assisted ceramic membrane reactors and call for comprehensive toxicity analyses of effluents from the advanced oxidation processes.

AB - A ceramic membrane reactor (CMR) integrated with in-situ UV/O3 was assessed for post-treatment of the effluent out of an up-flow anaerobic sludge blanket (UASB) reactor treating real textile wastewater, focusing on the transformation of dissolved organic matter (DOM). Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) revealed the transformation of heteroatomic DOM containing S, N or both to simpler DOM containing mainly C, H, and O atoms. The decreased N contents in products (N/C = 0.0249) compared to precursors (N/C = 0.0311) and the higher O/C ratios in the N-containing products suggest the removal of R–NH2 groups accompanying DOM oxidation. While, S-containing compounds in the products had lower O/C and H/C ratios, suggesting a reduced state and the transformation of R–SO3 to R–S–R. H-abstraction and OH addition were identified as the primary oxidation mechanisms, thus enhancing the dominance of highly unsaturated and phenolic DOM in the effluent (70.3%) compared to the feed (56.6%). The double bond equivalent (DBE) was also increased by 26% in the effluent compared to the feed and by 33% in products compared to precursors. These findings help understand the DOM transformation in UV/O3-assisted ceramic membrane reactors and call for comprehensive toxicity analyses of effluents from the advanced oxidation processes.

KW - Ceramic membrane

KW - Dissolved organic matter

KW - Fouling control

KW - Textile wastewater

KW - Ozonation

U2 - 10.1016/j.chemosphere.2022.136101

DO - 10.1016/j.chemosphere.2022.136101

M3 - 文章

C2 - 35998728

SN - 0045-6535

VL - 307

JO - Chemosphere

JF - Chemosphere

ER -