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The present study is focused on the synthesis of zero-valent iron/cellulose acetate (Fe0-x/CA) membranes by phase inversion route for the activation of peroxymonosulfate (PMS). The generated •OH and SO4•− effectively degraded methylene blue (MB) dye in water to give comparatively non-toxic byproducts. The SEM investigations revealed that Fe0 nanoparticles are evenly dispersed into the CA membrane resulting in decline of agglomeration and enhancing the roughness of the composite surface. Moreover, the catalytic degradation of MB demonstrated that M5-alone showed 85% and was further boosted to 97% when coupled with PMS (M5/HSO5−). The catalytic degradation of degradation of MB by M5/HSO5− membrane system in acidic, neutral, and basic media indicated that the degradation was 99.5%, 98.0%, 97.0%, 86.0% and 70.0% when the pH of the medium was 3, 5, 7, and 11, respectively. Furthermore, the degradation performance of M5/HSO5− membrane system was evaluated in de-ionized water (DIW), tape water (TPW) and industrial wastewater (IWW) and the results indicated that MB catalytic degradation was in the order of DIW (97%) > TPW (84%) > IWW (68%). Besides, various parameters like water flux permeability, contact angle, porosity, and fouling performance were also investigated. In addition, the degradation products were evaluated, and the degradation pathways were proposed accordingly. [ABSTRACT FROM AUTHOR]

This study is focused on synthesis of highly efficient Titania/reduced Graphene Oxide (TiO2/rGO) nanocomposites by means of simple hydrothermal technique. The TiO2/rGO were synthesized in different ratios of 0.5, 1.0, 2.0, and 3% by varying the concentration of rGO while the concentration of TiO2 was kept constant and the obtained samples were designated as TrG0.5, TrG1, TrG2, and TrG3 respectively. Different characterization techniques (SEM, TEM, HRTEM, XRD, EDX, TGA, UV-DRS, PL, EIS, and BET) showed high crystallinity, small crystallite size (18.4 nm), high thermal stability, high purity, low band gap energy (Eg = 3.12 eV), and high surface area (65.989 m2/g) for the as-synthesized TiO2/rGO nanocomposite. The efficiencies of TiO2/rGO were determined in terms of brilliant green (BG) dye degradation in aqueous media under UV light. The results revealed that 2% TiO2/rGO (TrG2) showed high efficiency for BG degradation with the kapp of 0.023 min−1 compared to TiO2 alone (kapp of 0.006 min−1). The rate of BG degradation was further synergised by the addition of peroxymonosulfate (PMS) to the system. The degradation of BG was improved to 99.4% by the incorporation of PMS in aqueous media compared to TrG2 alone. Furthermore, the degradation of BG was also examined in various media (neutral, acidic, and basic). The results revealed that by increasing pH of the medium from 3.85 to 8.2 the degradation of BG was enhanced from 99.4 to 99.9% with the corresponding kapp of 0.0602 min−1. Moreover, the photocatalytic degradation of BG followed the pseudo-first-order kinetics. Radical scavenging experiments showed that ●OH and SO4●– were the main species responsible for the degradation of BG under UV light. Besides, for determining the efficiency of as-synthesized TrG2/PMS system, the degradation of BG was also performed in various water types (distilled water, tape water, synthetic wastewater, and industrial wastewater). The degradation products (DPs) of BG and their corresponding pathways were proposed, accordingly. [ABSTRACT FROM AUTHOR]

The removal of brilliant green (BG), a toxic organic and cationic dye, has been examined by UV/S 2 O 8 2− (PS), UV/HSO 5 − (PMS) and UV/H 2 O 2 processes. BG showed insignificant direct photolysis at 254 nm (i.e., 8.6% after 30 min). However, enhanced BG degradation was observed in UV/PS, UV/PMS and UV/H 2 O 2 systems as revealed from 63.1, 47.0 and 34.8% BG degradation, respectively, at 30 min of reaction time, using 0.05 mM BG and 1.0 mM oxidant initial concentration. The bimolecular rate constants of OH and SO 4 − with BG were determined to be 2.35 × 10 9 and 2.21 × 10 9 M −1 s −1 , respectively. Electrical energy per order (EE/O) values for UV/PS, UV/PMS and UV/H 2 O 2 processes were calculated to be 5.4, 6.8, and 7.8 KWh/m 3 /order, respectively. The addition of humic acid (HA) and inorganic anions inhibited the degradation of BG by UV/PS in the order of NO 2 −  > HA > HCO 3 −  > Cl −   > NO 3 −  ≈ SO 4 2− . The results of frontier electron densities (FEDs) showed that C-atom holding the three rings (C7), and C-atoms at para positions to N-alkyl groups of the two rings (C4 and C14) are the predominant sites for radical addition. Furthermore, nine degradation products (DPs) of BG were detected experimentally using LC/MS/MS. [ABSTRACT FROM AUTHOR]