A Pilot Study of a Hybrid Process Involving In Situ Regenerated Activated Carbon, Membrane Separation and Advanced Oxidation for Water Pollution Abatement

The assessment of a pilot-scale hybrid system coupling powdered activated carbon (PAC) adsorption with membrane ultrafiltration (UF), in respect of activated carbon regeneration and organic micropollutant removal, was investigated in this study. Field tests with two adsorbents (i.e. a commercial PAC and a PAC-Fe(II) composite), conducted in the premises of Thessaloniki Water Treatment Plant, demonstrated the high efficiency of the combined PAC/UF process. Regeneration efficiencies varying between approximately 95% and 110%, complete diclofenac (DCF) degradation and rather moderate mineralization (TOC removal) rates of up to 47%, can be achieved by UVC/H2O2 or photo-Fenton oxidation after 4 hours of treatment; this performance is attributed to the in situ generation of reactive oxidant species by photolysis of H2O2, which seems to enhance the process effectiveness. Among the two adsorbent materials tested, composite PAC-Fe(II) exhibited a higher DCF adsorption capacity than the original PAC, probably due to the improved chemisorption and/or the electrostatic attractive interactions between the negatively charged DCF molecules and the positively charged iron species, at neutral pH. Furthermore, a rather insignificant effect of PAC-Fe(II) loading on the regeneration efficiency was observed. The advantages of totally controlled H2O2 dosages and short operating times render the hybrid PAC/UF system a promising alternative to conventional and advanced drinking water purification methods

Antifouling behavior and separation performance of immobilized TiO2 in dual layer hollow fiber membranes

A set of titanium dioxide/polyvinylidene fluoride (TiO 2 /PVDF) dual layer hollow fiber (DLHF) membranes with various weight ratios (i.e., 0, 0.2. 0.5, 0.7, and 1) were prepared. This work investigated the effect of TiO 2 loading and ultraviolet (UV) irradiation intensity toward the separation performance using nonylphenol (NP) solution as the model sample. The study showed that TiO 2 nanoparticles were well distributed at the outer layer of DLHF membranes at lower concentration, but the particles were aggregated at higher concentration. The membrane with 0.2 TiO 2 /PVDF ratios showed uniform dispersion of TiO 2 and consequently recorded excellent NP solution flux. In the presence of UV light, the activation of super hydrophilicity properties of TiO 2 nanoparticles was improved and it was highly activated at higher energy, which results in the significant increase of NP solution flux. The results provide vital insights into the development of immobilized TiO 2 in DLHF membranes and applications in water treatment. POLYM. ENG. SCI., 58:1636–1643, 2018. © 2017 Society of Plastics Engineers

Degradation of Recalcitrant Textile Dyes by Coupling Fungal and Photocatalytic Membrane Reactors

WOS: 000387805500010White rot fungi have powerful and broad specific extracellular enzymatic systems and can degrade multiple types of recalcitrant compounds including azo dyes, therefore, they are used in the field of bioremediation. In the present study, decolorization and organic matter removal of Acid Red 88 (AR88) and Reactive Red 180 (RR180) dye solutions were performed using the white rot fungus Phanerochaete chrysosporium in a bioreactor. Degradation of the dyes was assessed using a hybrid process consisting of a fungal membrane bioreactor coupled with a photocatalytic membrane reactor. The photocatalytic oxidation step was conducted using the semiconductor ZnO as the catalyst with UVA irradiation. Experimental data with the fungal membrane bioreactor showed that the optimum pH was 4.5 for P. chrysosporium. Integrating photocatalytic step after the fungal membrane process improved the chemical oxygen demand (COD) removal efficiency up to 98 and 96% for RR180 and AR88 dye solutions, respectively. Color removal efficiencies after the photocatalytic degradation were 99.9% for both dye solutions.Scientific and Technological Research Council of Turkey (TUBITAK) [113Y334]The authors thank The Scientific and Technological Research Council of Turkey (TUBITAK) for their financial support (Project number: 113Y334)