Photocatalytic degradation of methamphetamine by UV/TiO2-Kinetics, intermediates, and products
Journal
Water Research
Journal Volume
74
Pages
1-9
Date Issued
2015
Author(s)
Abstract
Methamphetamine (MAT) is a prescription drug and often a substance of abuse. It is found in WWTP influents and effluents as well as surface waters in many regions, elevating concerns about their potential impact. MAT is not effectively removed by conventional processes of domestic wastewater treatment plants (WWTPs). To contemplate advanced treatment, this study evaluates the feasibility of eliminating MAT by UV-illuminated TiO2, a potential retrofit to existing UV disinfection units. The degradation kinetics and mechanism of MAT by TiO2 under low-wattage UV illumination (9W with maximum output at 365nm) were investigated. Experimental parameters were varied including the TiO2 loading, MAT concentration, and pH. During treatment, MAT and its intermediates were tracked by HPLC-MS/MS, along with TOC and IC measurements to determine the mineralization extent. In contact with 0.1g/L of TiO2 under illumination at pH 7, an entire spike amount of 100μg/L of MAT was removed from deionized water after 3min and 76μg/L of MAT was removed from the secondary wastewater effluent after 30min. The degradation of MAT followed an apparent first-order kinetics. Near complete mineralization of MAT from 10mg/L was achieved in 180min with 0.1g/L of TiO2 at pH 5, by which the organic nitrogen was converted to NH4+ and NO3-. Based on identified intermediates, two degradation pathways were deduced that involved cleavage of the side chain as well as hydroxylation of the MAT compound. The photocatalytic UV/TiO2 process shows promise in arresting the release of MAT and its intermediate derivatives into the water environment. © 2015 Elsevier Ltd.
Subjects
Degradation mechanism; Illicit drugs; Intermediates; Kinetics; Mineralization; Photocatalysis
Other Subjects
Degradation; Deionized water; Drug products; Enzyme kinetics; Kinetics; Loading; Mineralogy; Photocatalysis; Titanium dioxide; Wastewater treatment; Degradation mechanism; Degradation pathways; Domestic wastewater treatment plants; Experimental parameters; Illicit drug; Intermediates; Mineralization; Photo catalytic degradation; Effluents; methamphetamine; methamphetamine; titanium; titanium dioxide; waste water; water pollutant; concentration (composition); disinfection; domestic waste; mineralization; photochemistry; photodegradation; reaction kinetics; wastewater; Article; degradation kinetics; hydroxylation; mineralization; photocatalysis; priority journal; ultraviolet irradiation; waste water treatment plant; water contamination; water treatment; chemistry; feasibility study; kinetics; photolysis; prevention and control; procedures; radiation response; ultraviolet radiation; waste water; water management; water pollutant; water pollution; Feasibility Studies; Kinetics; Methamphetamine; Photolysis; Titanium; Ultraviolet Rays; Waste Water; Water Pollutants, Chemical; Water Pollution, Chemical; Water Purification
Publisher
Elsevier Ltd
Type
journal article