Photocatalytic Removal of Microbiological Consortium and Organic Matter in Greywater

Abstract

This study aimed to investigate TiO 2 photocatalytic degradation of synthetically-prepared greywater samples with differing compositional contents of organic matter (OM), anion concentration, and microbiological consortium. Treatment efficiency was followed through removal of organic matter content in terms of dissolved organic carbon (DOC), specific spectroscopic parameters, and bacterial inactivation. Photocatalytic degradation kinetics were expressed by pseudo first-order kinetic modeling. The best DOC removal rates were attained for greywater samples containing OM with lower molecular size fractions. In addition, either enhancing or reducing the effect of common anions as radical scavengers were observed depending on the composition and concentration of variables in the greywater matrix. Moreover, possibility of a photocatalytic disinfection process was found to be of a bacteria type specific in OM-loaded synthetic greywater samples. Photocatalytic destruction of fecal streptococci required longer irradiation periods under all conditions. Bacterial removal rates were found to be in the order of total coliform > fecal coliform > fecal streptococci, for low organic load greywater, and fecal coliform > total coliform > fecal streptococci, for high organic load greywater.

Fabrication and Application of Photocatalytic Composites and Water Treatment Facility Based on 3D Printing Technology

“…Therefore, the secondary pollution to the environment is fundamentally eliminated. TiO 2 is the most common photocatalyst due to its low cost, good photosensitivity, and resistance to light corrosion [ 13 ]. However, its forbidden band width is larger, thus metal doping is often used to reduce its band gap, thereby improving its catalytic performance.…”

Catalyst Recovery, Regeneration and Reuse during Large-Scale Disinfection of Water Using Photocatalysis

“…The studies referenced in Figure S2 as well as the current work investigate the disinfection kinetics in isolation, as they study the inactivation rates of E. coli in absence of any other contaminants in the water. The photocatalytic disinfection of water from actual ground and surface water sources, as well as wastewater, needs consideration of the effects of total organic carbon (TOC) and the presence of various salts in the water as reported by Abidi et al [39], Moncayo-Lasso et al [40] and Birben et al [41]. However, such studies need to be performed on a larger scale to better understand the challenges of scaling up the photocatalytic disinfection process.…”

Titanium-based photocatalytic coatings for bacterial disinfection: The shift from suspended powders to catalytic interfaces

“…Heterogeneous photocatalysis includes semiconductor materials like TiO2, CdS, ZnO, ZnS, and ZrO2 and homogeneous photocatalysis contains Photo-Fenton treatment [100], Photocatalytic Ozonation (O3/UV) [101], Photolysis of hydrogen peroxide (UV/H2O2) [102], Peroxone Process (O3/H2O2) [103,104], and Vacuum Ultraviolet (VUV) [105,106]. Photocatalytic processes were reported to remove Natural Organic Matter (NOM) [107][108][109], pesticides [110][111][112], pharmaceutical and personal care products (PPCPs) [113][114][115]. So far, many studies have carried out for bacterial inactivation in water [116].…”