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This study is focused on the synthesis of a solar light driven novel poly(vinyl alcohol) (PVA)-assisted TiO2/Ti film via a facile one pot hydrothermal technique and then its photocatalytic applications by adding with peroxymonosulfate (PMS) for efficient degradation of ciprofloxacin (CIP). The key hydrothermal synthesis parameters like PVA-content, hydrothermal time (HT), and pH were optimized. The best photocatalytic performance of the synthesized material was observed when prepared with the conditions of PVA = 8 mg, HT= 3 h, and pH = 2.62. Results showed that 98.3% of CIP was degraded within 60 min by PVA-assisted TiO2/Ti film with 0.5 mM PMS added, compared to 89.38% and 88.86% degradation with 0.5 mM persulfate (PS) and 0.5 mM hydrogen peroxide (H2O2), respectively. The photocatalytic degradation of CIP by PVA-assisted TiO2/Ti film with PMS added was dependent on the [PMS]0and increased with increase in [PMS]0. The kappvalues at [PMS]0of 0.2, 0.5, 0.8, and 1.0 mM were 0.029, 0.0582, 0.068, and 0.128 min–1, respectively. The photocatalytic degradation of CIP by PVA-assisted TiO2/Ti film with PMS added under solar light irradiation was highly dependent on the [pH]0as well as on the presence of coexisting anions like HCO3–, CO32–, NO2–, Cl–, and SO42–. Natural organic matter (NOM) retarded the photocatalytic degradation of CIP by PVA-assisted TiO2/Ti film with PMS added under solar light irradiation due to its strong scavenging ability toward •OH and SO4•–. The photocatalytic degradation of CIP by as-prepared photocatalyst under solar light irradiation was higher in Milli-Q water (kapp= 0.0582 min–1) than tap water (kapp= 0.0342 min–1) followed by river water (kapp= 0.0259 min–1) and then synthetic wastewater (kapp= 0.0212 min–1). The degradation products of CIP were investigated by UPLC-MS/MS, and accordingly degradation pathways were proposed. Moreover, the mineralization, ecotoxicity, and cyclic photocatalytic stability of the as-prepared photocatalyst were also investigated. These findings suggest that as-prepared PVA-assisted TiO2/Ti film with PMS added is a promising alternative for the treatment of wastewater containing antibiotics.

Nitrogen-doped titanium dioxide (N-TiO2) nanoparticles were prepared using a modified sol-gel method. The as-prepared nanoparticles were characterized by state-of-the-art techniques for their optical, structural and morphological properties. The crystallite size, surface area and bandgap energy of reference TiO2and N-TiO2nanoparticles were found to be 16.1 and 10.9 nm, 83.6 and 131.8 m2g−1and 3.23 and 2.89 eV, respectively. The photocatalytic activities, in terms of 2,4-dichlorophenol (2,4-DCP) degradation, of reference TiO2and N-TiO2were found to be 46.9% and 65.4% at 120 min of treatments under UV light irradiation and 21.5% and 77.6% at 240 min of treatment under visible light irradiation, employing 153.4 µM 2,4-DCP, 1 g/L photocatalyst dosage, and pH 5.6. Interestingly, considerable H2production rate (i.e., 386 μmol h−1g−1) was observed for visible/N-TiO2system in presence of 0.2 wt% Pt. The study revealed that visible/N-TiO2photocatalytic system can be used as an economically viable technology for environmental sustainability.

The oxidative degradation of CV dye in aqueous media has been evaluated using Fenton (Fe2+/H2O2) and photo-Fenton (Fe2+/H2O2/UV) processes. Various operational parameters like H2O2dosages, Fe2+dosages and [CV]0were optimized of both Fenton and photo-Fenton processes for the removal of CV dye from aqueous media. Kinetic results indicated that photo-Fenton process (kobs=0.0097 min−1, t1/2=71.45 min) is more effective than Fenton process (kobs=0.0074 min−1, t1/2=93.66 min). Second order rate constant of ˙OH radical with CV dye was calculated to be 3.96×109M−1s−1. De-methylated organic intermediates of CV dye detected by LC-MS and some other intermediates like CH3COO−, HCOO−, NH4+and Cl−were identified by ion-chromatography.

Extensive research has been conducted on controlling carbon dioxide (CO2), sulfur oxides (SOx), and nitrogen oxides (NOx) emissions in recent years with increasing environmental awareness. The primary contributor to climate change is the exponentially growing anthropogenic CO2, NOx,and SOxin the air from various energy and industrial sectors. Hence, several pre-combustion and post-combustion processes to mitigate these gases have been introduced and implemented. Despite the benefits of CO2, SOx, and NOxabatement technologies, researchers still have major challenges to deal with. While the removal efficiencies, operational costs, and resulting byproducts of conventional removal technologies are being improved, new technologies are also emerging. As it is evident from the current abundant reserves of coal that it will continue to be in a significant position among the principal sources of energy for more than a decade, the research for the reduction of CO2, NOx,and SOxis inevitable to save future generations from the harmful impacts of these pollutants. This review paper summarizes the progress of different emission control technologies at the plant level and introduces emerging technologies that are environment friendly.