engleski

Designing a hybrid ozonation-filtration process using modified ceramic membranes for increasing the hydroxyl radical yield in wastewater treatment

Water ozonation is a standard process applied to reduce the concentration of the organic micropollutants’ (OMPs) in effluent. Since the ozonation is slow for many OMPs, it is desirable to increase the conversion of ozone to hydroxyl radicals, thus reducing its required dose. Likewise, membrane processes of different pore sizes and compositions can be used to reduce the concentration of OMPs in water. Recently, ceramic membranes (CMs) have gained increasing attention because they can provide long-term durability and filtration integrity. The aim of this study is to develop and implement a hybrid ozonation-filtration wastewater treatment process where their synergy will come into play in improving OMPs removal efficiency. In preliminary experiments, different metal oxides (α-Al2O3, γ- Al2O3, Mn2O3, CeO2, and TiO2) were used in batch experiments to test their catalytic activity towards heterogeneous ozonation, in the order to choose the most efficient one. Four commercial CMs with different compositions and pore sizes were used: three ultrafiltration (UF) ceramic membranes of TiO2/ZrO2 composition with 50 kDa, 150 kDa and 300 kDa molecular weight cut-off (MWCO) respectively, and a microfiltration (MF) ceramic membrane of TiO2/ZrO2+TiO2 composition with a pore size of 200 nm. The surface of the ceramic membranes was coated by with the most promising oxide using sol-gel method ; the modified membranes were analyzed by various techniques (XRD, SEM-EDS, AFM, BET). The characterizations were used to explain the behavior of the membranes in the presence of ozone. Such membranes will be used as a tool to increase the yield of hydroxyl radicals and thus, ensure increased removal or degradation of selected OMPs (mixture of amoxicillin, carbamazepine, ibuprofen and diclofenac) in the wastewater while reducing membrane fouling.

Wastewater Reuse ; Organic Micropollutants ; Membrane Separation ; Ceramic Membrane

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