Effluent organic matter （EfOM） is the major cause of fouling in the low pressure membranes process for wastewater reuse. Coagulation and oxidation of biological wastewater treatment effluent have been applied for th...Effluent organic matter （EfOM） is the major cause of fouling in the low pressure membranes process for wastewater reuse. Coagulation and oxidation of biological wastewater treatment effluent have been applied for the fouling control of microfiltration membranes. However, the change in EfOM structure by pre-treatments has not been clearly identified. The changes of EfOM characteristics induced by coagulation and ozonation were investigated through size exclusion chromatography, UV/Vis spectrophotometry, fluorescence spectrophotometry and titrimetric analysis to identify the mechanisms in the reduction of ultrafiltration （UF） membrane fouling. The results indicated that reduction of flux decline by coagulation was due to modified characteristics of dissolved organic carbon （DOC） content. Total concentration of DOC was not reduced by ozonation. However, the mass fraction of the molecules with molecular weight larger than 5 kDa, fluorescence intensity, aromaticity, highly condensed chromophores, average molecular weight and soluble microbial byproducts decreased greatly after ozonation. These results indicated that EfOM was partially oxidized by ozonation to low molecular weight, highly charged compounds with abundant electron- withdrawing functional groups, which are favourable for alleviating UF membrane flux decline.展开更多
Herein,the innovative hybrid photocatalyst PET-based Zn-MOF on orange peel biochar(BC)(PZM/BC)was designed and synthesized via the hydrothermal method.Electrochemical methods have been used to demonstrate the action o...Herein,the innovative hybrid photocatalyst PET-based Zn-MOF on orange peel biochar(BC)(PZM/BC)was designed and synthesized via the hydrothermal method.Electrochemical methods have been used to demonstrate the action of the PET-MOF in the PZM/BC photocatalyst as a medium for electron transfer.The latter involved the synthesis of a zinc-containing metal-organic framework(MOF)in which the linkers were derived from the depolymerization of polyethylene terephthalate(PET)originating from plastic wastes.According to research,the catalytic reactions are sped up when porous BC and linker PET are assimilated into PZM/BC photocatalyst hetero-junction.Furthermore,BC stored electrons under light and released these electrons under dark conditions.When BC was combined with PET-MOF,the electrons on the biochar activated the catalytic redox activity of acetaminophen.Additionally,it lowers the reassimilation rate due to the combined meshed nanostructures and functionality of PET-MOF and PZM/BC.UV-Vis DRS,Mott-Schottky,Photoluminescence(PL),and Electrochemical Impedance spectra(EIS)results showed that the PZM/BC exhibited efficient spatial separation and transportation of photogenerated charge carriers and exhibited superior photocatalytic ability.Electron spin resonance(ESR)analysis confirmed that⋅OH and h+were the predominant radical species responsible for the degradation of acetaminophen(ACT).The optimum conditions for ACT removal were observed at pH 6.07,with a PZM/BC dosage of 0.1 g L^(−1),and an initial ACT concentration of 50 mg L^(−1),highlighting the pivotal role of the PZM/BC system in ACT degradation.Furthermore,potential photocatalytic degradation pathways of ACT were inferred renders on the identified intermediates which are responsible for the degradation of refractory intermediates.Regeneration trials were carried out to assess the stability of the photocatalyst.Additionally,the degraded intermediates generated during the degradation processes were examined,providing a comprehensive elucidation of the degradation mechanism.展开更多
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MEST) (No. 2012R1A1B3002152, 2013R1A2A2A03016095)
文摘Effluent organic matter （EfOM） is the major cause of fouling in the low pressure membranes process for wastewater reuse. Coagulation and oxidation of biological wastewater treatment effluent have been applied for the fouling control of microfiltration membranes. However, the change in EfOM structure by pre-treatments has not been clearly identified. The changes of EfOM characteristics induced by coagulation and ozonation were investigated through size exclusion chromatography, UV/Vis spectrophotometry, fluorescence spectrophotometry and titrimetric analysis to identify the mechanisms in the reduction of ultrafiltration （UF） membrane fouling. The results indicated that reduction of flux decline by coagulation was due to modified characteristics of dissolved organic carbon （DOC） content. Total concentration of DOC was not reduced by ozonation. However, the mass fraction of the molecules with molecular weight larger than 5 kDa, fluorescence intensity, aromaticity, highly condensed chromophores, average molecular weight and soluble microbial byproducts decreased greatly after ozonation. These results indicated that EfOM was partially oxidized by ozonation to low molecular weight, highly charged compounds with abundant electron- withdrawing functional groups, which are favourable for alleviating UF membrane flux decline.
基金support for this study was provided by the Korean government through the National Research Foundation of Korea(NRF),under Grant No.2022R1A2B5B02001584.
文摘Herein,the innovative hybrid photocatalyst PET-based Zn-MOF on orange peel biochar(BC)(PZM/BC)was designed and synthesized via the hydrothermal method.Electrochemical methods have been used to demonstrate the action of the PET-MOF in the PZM/BC photocatalyst as a medium for electron transfer.The latter involved the synthesis of a zinc-containing metal-organic framework(MOF)in which the linkers were derived from the depolymerization of polyethylene terephthalate(PET)originating from plastic wastes.According to research,the catalytic reactions are sped up when porous BC and linker PET are assimilated into PZM/BC photocatalyst hetero-junction.Furthermore,BC stored electrons under light and released these electrons under dark conditions.When BC was combined with PET-MOF,the electrons on the biochar activated the catalytic redox activity of acetaminophen.Additionally,it lowers the reassimilation rate due to the combined meshed nanostructures and functionality of PET-MOF and PZM/BC.UV-Vis DRS,Mott-Schottky,Photoluminescence(PL),and Electrochemical Impedance spectra(EIS)results showed that the PZM/BC exhibited efficient spatial separation and transportation of photogenerated charge carriers and exhibited superior photocatalytic ability.Electron spin resonance(ESR)analysis confirmed that⋅OH and h+were the predominant radical species responsible for the degradation of acetaminophen(ACT).The optimum conditions for ACT removal were observed at pH 6.07,with a PZM/BC dosage of 0.1 g L^(−1),and an initial ACT concentration of 50 mg L^(−1),highlighting the pivotal role of the PZM/BC system in ACT degradation.Furthermore,potential photocatalytic degradation pathways of ACT were inferred renders on the identified intermediates which are responsible for the degradation of refractory intermediates.Regeneration trials were carried out to assess the stability of the photocatalyst.Additionally,the degraded intermediates generated during the degradation processes were examined,providing a comprehensive elucidation of the degradation mechanism.
