Evaluation and comparison of advanced oxidation processes for the degradation of 2,4-dichlorophenoxyacetic acid (2,4-D): a review

• Published in: Environmental science and pollution research international 2021-06, Vol.28 (21), p.26325-26358
• Main Authors: Girón-Navarro, Rocío, Linares-Hernández, Ivonne, Teutli-Sequeira, Elia Alejandra, Martínez-Miranda, Verónica, Santoyo-Tepole, Fortunata
• Format: Article
• Language: English
• Subjects: 2,4-D; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Catalysts; Contamination; Degradation; Dichlorophenoxyacetic acid; Earth and Environmental Science; Ecotoxicology; Electrochemistry; Energy costs; Environment; Environmental Chemistry; Environmental degradation; Environmental Health; Environmental science; Hydrogen peroxide; Iron; Low concentrations; Mineralization; Organic compounds; Organochlorine pesticides; Oxidation; Ozonation; Pesticides; Photocatalysis; Pollutants; Public concern; Review Article; Tin dioxide; Titanium dioxide; Toxicity; Ultraviolet radiation; Waste Water Technology; Wastewater; Water Management; Water pollution; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-021-13730-y

Organochlorine pesticides have generated public concern worldwide because of their toxicity to human health and the environment, even at low concentrations, and their persistence, being mostly nonbiodegradable. The use of 2,4-dichlorophenoxyacetic acid (2,4-D) has increased in recent decades, causing severe water contamination. Several treatments have been developed to degrade 2,4-D. This manuscript presents an overview of the physicochemical characteristics, uses, regulations, environmental and human health impacts of 2,4-D, and different advanced oxidation processes (AOPs) to degrade this organic compound, evaluating and comparing operation conditions, efficiencies, and intermediaries. Based on this review, 2,4-D degradation is highly efficient in ozonation (system O 3 /plasma, 99.8% in 30 min). Photocatalytic, photo-Fenton, and electrochemical processes have the optimal efficiencies of degradation and mineralization: 97%/79.67% (blue TiO 2 nanotube arrays//UV), 100%/98% (Fe 2+ /H 2 O 2 /UV), and 100%/84.3% (MI-meso SnO 2 ), respectively. The ozonation and electrochemical processes show high degradation efficiencies, but energy costs are also high, and photocatalysis is more expensive with a separation treatment used to recover the catalyst in the solution. The Fenton process is a viable economic-environmental option, but degradation efficiencies are often low (50–70%); however, they are increased when solar UV radiation is used (90–100%). AOPs are promising technologies for the degradation of organic pollutants in real wastewater, so evaluating their strengths and weaknesses is expected to help select viable operational conditions and obtain optimal efficiencies.