Ultrasound enhancement of near-neutral photo-Fenton for effective E. coli inactivation in wastewater

Abstract

a b s t r a c tIn this study, we attempt for the first time to couple sonication and photo-Fenton for bacterial inactivation of secondary treated effluent. Synthetic wastewater was subjected to sequential high-frequency/low power sonication, followed by mild photo-Fenton treatment, under a solar simulator. It was followed by the assessment of the contribution of each component of the process (Fenton, US, hv) towards the removal rate and the long-term survival; sunlight greatly improved the treatment efficiency, with the coupled process being the only one to yield total inactivation within the 4-h period of treatment. The short-term beneficial disinfecting action of US and its detrimental effect on bacterial survival in long term, as well as the impact of light addition were also revealed. Finally, an investigation on the operational parameters of the process was performed, to investigate possible improvement and/or limitations of the coupled treatment; 3 levels of each parameter involved (hydraulic, environmental, US and Fenton) were tested. Only H 2 O 2 increased improved the process significantly, but the action mode of the joint process indicated potential cost-effective solutions towards the implementation of this method.

Sonolysis and sono-Fenton oxidation for removal of ibuprofen in (waste)water

“…In order to investigate the efficiency in real application, some experiments with a real wastewater matrix (WW) were performed. Wastewater consists in a complex mixture of organic and inorganic compounds, such as nutrients, salts and many substances that could influence the outcome of advanced oxidation processes [54]. For instance, the presence of organic (humic acid, fulvic acid, etc.)…”

Heterogeneous Advanced Oxidation Processes: Current Approaches for Wastewater Treatment

“…These radicals released in the main solution allow the degradation of organic pollutants followed by their partial/total mineralization to carbon dioxide, water and inorganic ions [20,21]. These oxidation processes include chemical (Fenton or Fenton-like), photochemical (photo-Fenton or photocatalysis), electrochemical (anodic oxidation, electro-Fenton, electrophotocatalysis) and sonochemical (sono-Fenton) processes and process combinations (photo-electro-Fenton, sono-electro-Fenton) [22][23][24]. The activation of the above-mentioned precursor compounds is carried out via multiple alternatives such as the use of transition-metal-based catalysts (Fe, Mn, Co, Cu, V, Ru, Mo, Cr, Ce), heat, UV radiation or visible light, ultrasound and/or alkalinity of the liquid medium [25][26][27].…”

Inactivation of pathogenic microorganisms in freshwater using HSO5−/UV-A LED and HSO5−/Mn+/UV-A LED oxidation processes

“…The majority of DBPs are a consequence of the chlorination of naturally occurring organic precursors such as humic substances (WHO, 2008;Grellier et al, 2015). Consequently, finding alternative effective mean of water disinfection which simultaneously avoid the generation of disinfection by-products has attracted the attention of many investigators (Venieri et al, 2015;Ferro et al, 2015;Giannakis et al, 2015).…”