A critical review on current urea removal technologies from water: An approach for pollution prevention and resource recovery

Mechanistic investigation of the photocatalytic activity of PEDOT for aqueous contaminant removal: the role of iron and hydroxyl radicals

“…According to Weerakoon et al (2023), the pH-dependent photolysis of a compound under UV probably arises from two factors: type and intensity of UV and molar absorption coefficient of the organic contaminant. 42 Since the UV type and intensity was same, the higher degradation of hexazinone at acidic pH (Fig. 5A) can be attributed to combination of hexazinone being in neutral form and higher quantum yield.…”

Urea catalytic oxidation for energy and environmental applications

“…Due to excellent stability and low cost, TiO 2 photocatalysts have been extensively explored in water splitting, 209 selective organic synthesis,223 nitrogen fixation, 224 and urea conversion. 24 Pristine TiO 2 materials have a wide band gap and can absorb ultraviolet light to generate holes with strong oxidizing ability, and various oxidative species in the presence of water and oxygen. It has been reported that ˙OH exhibited UOR activity via dehydrogenation in TiO 2 photocatalysis.…”

“…It has been reported that ˙OH exhibited UOR activity via dehydrogenation in TiO 2 photocatalysis. 24 Noble metal modification is an effective strategy to boost charge separation/transfer within semiconductor photocatalysts and the generation of oxidative species. 225 Compared with bare TiO 2 , platinized TiO 2 exhibited nearly a 4-fold improvement in urea conversion.…”

“…225 Compared with bare TiO 2 , platinized TiO 2 exhibited nearly a 4-fold improvement in urea conversion. 24 This is because the supported Pt facilitated the electron transfer from bulk to surface and interfacial electron transfer to oxygen, thereby boosting hole-induced ˙OH generation. Additionally, non-metallic doping has been reported to regulate the surface properties and energy band structure of TiO 2 photocatalysts.…”

“…22,23 However, urease-catalysed urea hydrolysis is always accompanied by a post-treatment to remove hydrolysis products (NH 4 + and CO 3 2− /HCO − ), which introduces additional costs and treatment steps. 22–24 Alternative urea wastewater treatment methods, such as thermal hydrolysis, adsorption, and chemical oxidation, generally require high energy consumption (CO 2 emission) and operate under harsh working conditions. 25–30 Therefore, there is an urgent need to find novel, environmentally friendly, and sustainable urea wastewater treatment technologies.…”