Degradation of Diclofenac under Irradiation of UV Lamp and Solar Light Using ZnO Photo Catalyst

Diclofenac sodium (DCF) is a non-steroidal anti-inflammatory drug mainly used as an analgesic, arthritic and anti-rheumatic. This study deals with the degradation of diclofenac by photo catalytic-based advanced oxidation processes. Artificial UV lamp and solar rays have been applied to activate the ZnO catalyst, thereby generating highly oxidizing species. These species initiate the degradation process of the drug, which results in intermediates that finally dissociate into carbon dioxide and water. The solar reactor system is comprised of quartz and borosilicate tubes alternatively for the absorption and transmission of the solar rays to the pollutant sample. The degradation rate has been analyzed by composition analysis using high performance liquid chromatography. TOC and COD tests have also been conducted for degraded samples. ZnO catalyst loading was tested from 0.1 gm/L to 1 gm/L and the degradation rate showed a rising trend up to 0.250 gm/L, but further increase in loading resulted in a drop in degradation. Similarly, degradation is higher in acidic condition as compared to neutral or basic pH. The results showed a higher degradation rate for UV lamp irradiation as compared to the solar system. Moreover, TOC and COD reduction is also found to be higher for UV lamp photo catalysis.

Multifunctional Membranes—A Versatile Approach for Emerging Pollutants Removal

This paper presents a comprehensive literature review surveying the most important polymer materials used for electrospinning processes and applied as membranes for the removal of emerging pollutants. Two types of processes integrate these membrane types: separation processes, where electrospun polymers act as a support for thin film composites (TFC), and adsorption as single or coupled processes (photo-catalysis, advanced oxidation, electrochemical), where a functionalization step is essential for the electrospun polymer to improve its properties. Emerging pollutants (EPs) released in the environment can be efficiently removed from water systems using electrospun membranes. The relevant results regarding removal efficiency, adsorption capacity, and the size and porosity of the membranes and fibers used for different EPs are described in detail.

Dye Sensitization for Ultraviolet Upconversion Enhancement

Upconversion nanocrystals that converted near-infrared radiation into emission in the ultraviolet spectral region offer many exciting opportunities for drug release, photocatalysis, photodynamic therapy, and solid-state lasing. However, a key challenge is the development of lanthanide-doped nanocrystals with efficient ultraviolet emission, due to low conversion efficiency. Here, we develop a dye-sensitized, heterogeneous core–multishelled lanthanide nanoparticle for ultraviolet upconversion enhancement. We systematically study the main influencing factors on ultraviolet upconversion emission, including dye concentration, excitation wavelength, and dye-sensitizer distance. Interestingly, our experimental results demonstrate a largely promoted multiphoton upconversion. The underlying mechanism and detailed energy transfer pathway are illustrated. These findings offer insights into future developments of highly ultraviolet-emissive nanohybrids and provide more opportunities for applications in photo-catalysis, biomedicine, and environmental science.

Organic Pollutants Photo-Degradation by Steady g-C3N4 Nanorods for Wastewater Treatment Applications

The photo-catalysis is a promising method for the degradation of harmful organic pollutants existing in the wastewater. In this research work, degradation of organic pollutants (dyes) have been done proficiently for the wastewater treatment applications. The synthesized steady graphitic carbon nitride (g-C3N4) nanorods have been examined by various sophisticated characterization techniques such as XRD, SEM, EDS, TEM, UV-Vis and PL. The hexagonal phase of g-C3N4 has been showed in XRD analysis. SEM shows that the morphology of g-C3N4 consists of aggregated nanorods. The EDS depicting only two peaks which are carbon and nitrogen and nitrogen without impurities. According to the study of UV-Visible and PL, 2.77 eV band gap has been observed showing consistency. The steady g-C3N4 nanorods have been used for the degradation of prominent organic dyes such as: methylene orange (MO), methylene blue (MB) and rhodamine-B (Rh-B) for treatment of wastewater which is a dire need. The effect of catalyst mass loading and time have been studied for this purpose. This research depicted that the anion (•O2−) and holes (h+) are attributed to the degradation of organic pollutants. whose Rh-B, MB and MO dyes. Research based a tentative photocatalytic mechanism has also been proposed for waste treatment purpose.