Photocatalytic Porous Silica-Based Granular Media for Organic Pollutant Degradation in Industrial Waste-Streams

Abstract

Photocatalytic treatment of organic contaminants in industrial wastewaters has gained interest due to their potential for effective degradation. However, photocatalytic slurry reactors are hindered by solution turbidity, dissolved salt content, and absorbance of light. Research presented here introduces the development and application of a novel, photocatalytic, porous silica-based granular media (SGM). SGM retains the cross-linked structure developed during synthesis through a combination of foaming agent addition and activation temperature. The resultant media has a high porosity of 88%, with a specific surface area of ~150 m2/gram. Photocatalytic capabilities are further enhanced as the resultant structure fixes the photocatalyst within the translucent matrix. SGM is capable of photocatalysis combined with diffusion of nucleophiles, electrophiles, and salts from pore space. The photocatalytic efficiencies of SGM at various silica contents were quantified in batch reactors using methylene blue destruction over time and cycles. Methylene blue concentrations of 10 mg/L were effectively degraded (>90%) within 40 minutes. This effectiveness was retained over multiple cycles and various methylene blue concentrations. SGM is a passive and cost-effective granular treatment system technology which can translate to other organic contaminants and industrial processes.

Porphyrin-Based Nanomaterials for the Photocatalytic Remediation of Wastewater: Recent Advances and Perspectives

“…Considering the superiority of photocatalytic processes, several organic and inorganicbased nano-and micro-structures have emerged as new building blocks to fabricate photocatalytic systems. Various inorganic nanostructures, including metal oxide nanoparticles (MNPs) (TiO 2 [16,17] and ZnO [18,19]), graphitic carbon nitride (g-C 3 N 4 ) [20,21], silicates [22,23], zeolites [24,25], and bismuth-based photocatalysts [26,27], have been used to eliminate hazardous pollutants from wastewater. Titanium dioxide (TiO 2 ) has been used as an emerging catalyst because of its high stability, moderate toxicity, economic affordability, and excellent catalytic properties for the decay of toxic contaminants in aqueous solutions.…”

Silica-Based Superhydrophobic and Superoleophilic Cotton Fabric with Enhanced Self-Cleaning Properties for Oil–Water Separation and Methylene Blue Degradation

“…Silica has been widely utilized as a semiconductor photocatalyst for the degradation of organic pollutants. Research has shown that silica-based nanomaterials, such as simple silica nanoparticles (SiO 2 ), aminated silica nanoparticles (NH 2 –SiO 2 ), and silica-silver nanocolloids (Ag-SiO 2 ), have been tested as photocatalysts for pollutant degradation via an advance oxidation process. − Furthermore, silica-based cotton fabric has been developed, demonstrating the degradation ability. As opposed to other hydrophobic reagents, octadecylamine causes suitable surface etching and lowers the surface energy due to its long nonpolar chain.…”

Photoelectrocatalytic treatment and resource utilization of industrial waste salt for chlor-alkali electrolysis

“…Among them, AOPs enjoy good development and application prospects due to their strong oxidation ability gained through the generation of hydroxyl radicals (OH•) in addition to their low risk for secondary pollution. AOPs generally refer to catalytic wet oxidation (CWO) [7], O 3 oxidation [8], Fenton method [9], ultraviolet photolysis (UV) [8], electrochemical oxidation [10], photocatalytic oxidation [11] and their combined processes such as photoelectrocatalysis (PEC) [12]. The application of PEC to electrolyte with high conductivity and outstanding performance in concentrated waste brine treatment [13] has attracted increasing attention from researchers in recent years.…”