Droplet flow-assisted heterogeneous electro-Fenton reactor for degradation of beta-blockers: response surface optimization, and mechanism elucidation.

In this study, we report an effective degradation method for trace level beta-blockers (propranolol and acebutolol) in hospital wastewater using a new droplet flow-assisted heterogeneous electro-Fenton reactor (DFEF) system. Biogenic iron-carbon nanocomposites (RHS/C-x% Fe) as eco-friendly and low-cost heterogeneous Fenton catalysts were synthesized from rice husk via hydrolytic sol-gel routes. Here, we demonstrate the use of natural air as a nebulizing agent for fast and continuous catholyte air saturation and Fenton catalyst transfer to the cathode electrode. The effects of key operational parameters were evaluated and optimized using central composite design. Results clearly indicated that enhanced beta-blocker degradation was mainly dependent on the interactive effects of electrolysis time, current density, and catalyst dosage. Fast degradation efficiencies (≥ 99.9%) was recorded at neutral pH conditions. The decay followed pseudo-first-order kinetics with degradation rates of up to 2.72 × 10-2 and 2.54 × 10-2 min-1 for acebutolol and propranolol, respectively. The synergistic contribution of •OHbulk attributable to DFEF process and •OHadsorbed for anodic oxidation (AO) at the anode electrode significantly enhanced the degradation process. Compared to AO, the conventional flow-assisted electro-Fenton (FEF), and the batch electro-Fenton (BEF), DFEF degradation efficiency followed a decreasing order: DFEF ˃ FEF ˃ BEF˃ AO. This trend in performance was ...
Source: Environmental Science and Pollution Research International - Category: Environmental Health Authors: Tags: Environ Sci Pollut Res Int Source Type: research