The performance of different types of flower-like zinc oxide for photocatalytic desulfurization of synthetic thiophene

Zinc oxide (ZnO) nanoparticles have received great attention due to their advantages. Several improvements on the morphology of ZnO have been widely studied to solve the problem of agglomeration and surface-active sites. To date, there are limited studies involving the effect of flower-like ZnO in the application of thiophene desulfurization via photocatalysis process. Thus, this study focuses on the performance of different flower-like ZnO for synthetic thiophene desulfurization. Eight ZnO photocatalyst species were synthesised and categorized into two groups, namely flower-like ZnO and non-flower-like ZnO. The physical properties of all the ZnO morphologies were analysed. Moreover, their performances for desulfurization of synthetic thiophene were evaluated. From the findings, flower-like ZnO flakes showed the highest performance in synthetic thiophene desulfurization (30%). Higher pH (pH 11) and turbidity reduction (32%) of the permeate indicated the higher generation of hydroxyl radicals causing higher desulfurization of thiophene. From the kinetic study, all ZnO morphologies were applicable with pseudo-second-order models due to higher linear regression (R2 ) values. The highest concentration equilibrium, Ce value for flower-like ZnO flakes (909.09 mg/g) confirmed greater desulfurization of thiophene. Moreover, it was found that pH 7 in the presence of 0.05 g/L flower-like ZnO flakes for 90 minutes of irradiation were the best conditions and yield the highest desulfurization of 300 ppm synthetic thiophene (30%) due to the highest generation of hydroxyl radical. It is expected that this integrated approach could bring forward other initiative methods in overcoming the problems in petroleum industry related to desulfurization of sulphur-containing compounds

Photocatalytic degradation of dye wastewater

Dye wastewater is the major environmental issue of the textile and printing industries besides other minor issues like solid waste, health and safety. The use of synthetic chemical dyes in various manufacturing industrial process has increased considerably over the past decades, resulting in the release of dye-containing industrial effluents into aquatic ecosystem and soil [1]. Wastewater from printing and dyeing industries is frequently rich in color, containing residues of toxic chemicals, reactive dyes and requires proper treatment before all the effluent release into environment [2]. There are more than 8000 chemical products associated with all the dyeing, printing and finishing process listed in the color index, including some of the structural diverse of dyes, such as basic, acidic, reactive, disperse, azo, diazo, anthraquinone based and metal-complex dyes [1]. Therefore, these wastes must be genuine treated before it discharge to environment in order to comply with the environmental protection for the receiving water

Photocatalytic Degradation of Synthetic Sulfur Pollutants in Petroleum Fractions under Different pH and Photocatalyst

Thiophene is one of the sulfur compounds in the petroleum fraction that can be harmful to living things and lead to a critical effect on the ecosystem. Photocatalytic degradation is one of the promising methods in treating wastewater as it can mineralization of pollutants into carbon dioxide and water. Other than that, this method is non-toxic and relatively low cost. The production of hydroxyl radicals playing a vital role in the degradation of organic pollutants. It has been claimed that the usage of zinc oxide (ZnO) nanoparticles could give an excellent degradation process as this photocatalyst have high photosensitivity, low cost and chemically stable. However, the preparation method of ZnO nanoparticles will affect the agglomeration, particle size, shape and morphology of particles and lead to influence the photocatalytic activity in degrading thiophene. Therefore, this study focused on the effectiveness of ZnO nanoparticles in the presence of fibrous nanosilica (KCC-1) and polyethylene glycol (PEG) as the capping agent to degrade synthetic thiophene. ZnO/KCC-1 had been synthesized via the precipitation method and characterized by using Fourier Transform Infrared (FTIR). The chemical bond and nature of the photocatalyst from the FTIR results proved that the synthesis process to produce the ZnO/KCC-1 was succeed. The large surface area of KCC-1 increases the effectiveness of ZnO which is supported by the experimental data. Accordingly, the optimum condition for photocatalytic degradation of thiophene is under pH 7 by using ZnO/KCC-1 as photocatalyst. Hence, it is believed that this research could be implemented to remove the thiophene in petroleum fraction from the actual industrial effluents and this can preserve nature in the future

Catalytic conversion of synthetic sulfur-pollutants in petroleum fractions under different photocatalyst loadings and initial concentration

In the oil and gas industry which applied to petroleum sources, thiophene is one of the sulphur contaminants that may harm the environment. The contents of sulphur in petroleum product gives out concern regarding the negative and harmful effect of sulphur contaminants onto environment and living health. One of the promising methods to degrade thiophene is photocatalytic degradation process. The usage of ZnO nanoparticles in photocatalytic degradation process has been wider due to its broad band gap, greater excitation of energy binding, and high stability. Several studies have discovered the ability of ZnO with capping agent in photocatalytic activity. Photocatalytic activity of photo-catalyst was affected by particle size, shape and morphology that are depending on the preparation method. Hence, this study put on priori-ties on synthesizing ZnO nanoparticles using precipitation method with the addition of KCC-1 which act as capping agent and used in the degradation of synthetic thiophene solution. The characterization of ZnO-KCC-1 using FTIR has confirmed that the successfulness produc-tion of ZnO-KCC-1 via precipitation method. There are three different loading of ZnO-KCC-1 (0.05 g/L, 0.10 g/L and 0.15 g/L) and thio-phene concentration (100 ppm, 300 ppm and 600 ppm) had been carried out in photocatalytic degradation of thiophene. The pH value for all fixed condition remains constant at natural pH range which is pH 7. The optimum condition of degrading synthetic thiophene under natural pH range by using ZnO-KCC-1 is at its loading of 0.05 g/L with the initial concentration of synthetic thiophene of 300ppm.The kinetic study of this research has been confirmed to be at the first-order of kinetic reaction