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International Conference on

Recent Trends in Environmental Sustainability

ESCON22/NMsB/33
Investigating solar TiO2 photocatalysis for water treatment and environmental
applications

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1
Dr. Sanaullah Khan and Ms. Afsheena
1 Department of Chemistry, Women University Swabi, Swabi, Pakistan
Correspondence: sukhan3@gmail.com
Abstract

Organochlorine pollutants (OCPs) are highly toxic, more persistent, and ubiquitous
contaminants in the environment. Degradation of a model OCP, Lindane in water, by simulated
solar light-activated TiO2 (SSLA-TiO2) photocatalysis was investigated. Film types of TiO2
photocatalyst were prepared by a dip-coating method. The physical properties of the films were
investigated using X-ray diffraction, transmission electron microscopy, and scanning electron
microscopy. SSLA-TiO2 photocatalysis led to lindane removal of 23% in 6 h, corresponding
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to an observed rate constant (kobs) 0.042 h . The SSLA-TiO2 photocatalysis efficiency was
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greatly enhanced by adding hydrogen peroxide (H2O2), persulfate (S2O8 ) or both combined,
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corresponding to 64, 89 and 99% lindane removal in the presence of 200 µM of H2O2, S2O8
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or equimolar H2O2-S2O8 , respectively. The hydroxyl and sulfate radicals mainly participated
in lindane degradation, proven by results of radical scavenger study. Degradation efficiency
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decreased to 61, 35, 50, 70, 88 and 91% in 6 h, in the presence of 1.0 mg L humic acid (HA)
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or 1 mM CO3 , HCO3 , NO3 , SO4 and Cl , respectively. The SSLA-TiO2/S2O8 /H2O2
photocatalysis is very effective AOP for elimination of a persistent OCP, lindane from water
environment.
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Keywords: Lindane; Solar light TiO2 photocatalysis; S2O8 /H2O2; Natural water
constituents; Water treatment

Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus

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