Photocatalytic Transformation of Triclosan. Reaction Products and Kinetics

Abstract

5-Chloro-2-[2,4-dichlorophenoxy]-phenol, or triclosan (TCS), is an antimicrobial and antifungal agent with high resistance to conventional wastewater treatments, thus, more effective remediation technologies are necessary, where photocatalytic processes deserve special attention due to the high degradation rates of TCS, and the use of a renewable source of energy. However, different by-products may be formed during the treatment, sometimes more harmful than the parent compounds. Efforts to detail reaction pathways continually feed into related literature; however, knowing the transformation kinetics and the dependence on the operating variables is essential for the correct design of the abovementioned remediation technologies. This work contributes to increasing the knowledge necessary for the application of photocatalytic processes for the degradation of emerging pollutants, with TCS as a case study. First, an experimental plan to analyze the influence of the operating variables was carried out, determining time courses of the parent and intermediate compounds. Next, the kinetic model and parameters that are capable of predicting TCS concentration and its derivatives as a function of the operating conditions are provided. This constitutes a very useful tool to predict the performance of wastewater remediation treatment both in the degradation of the original pollutant and in the reduction of the toxicity in the treated water.

Nanomaterials for Removal of Phenolic Derivatives from Water Systems: Progress and Future Outlooks

“…Current techniques used for the removal of these compounds from water include electrochemical oxidation [ 31 , 32 , 33 , 34 ], adsorption by materials such as activated carbons [ 35 , 36 ], solvent extraction [ 37 ], photocatalytic degradation [ 38 , 39 , 40 ], advanced oxidations processes (AOPs) [ 33 , 41 , 42 , 43 ], and bioremediation using bacterial species and agricultural waste [ 42 , 43 , 44 , 45 ]. Among these methods, adsorption is particularly advantageous due to its ease of operation, both in batch and continuous processes, as well as the regeneration and reusability of the adsorbent materials.…”

Formation of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) in the electrochemical oxidation of polluted waters with pharmaceuticals used against COVID-19

“…Advanced Oxidation Processes (AOPs) are successfully applied technologies to the degradation of recalcitrant pollutants [44] , [45] , [46] . In particular, electrochemical oxidation (ELOX) has been extensively investigated for the mineralisation of several organic compounds [47] , [48] .…”