Investigation of Malathion Removal from Aqueous Solutions by Photocatalytic Process Combined with Persulfate and Hydrogen Peroxide

Malathion known as one of the most used organophosphates, with contact, digestive, fumigants and non-systemic properties has detrimental effects on ones nervous system. Recently use of photocatalyctic processes has grown widely because of its desirable ability to remove organic pollutants. In this study efficiency of photocatalytic process with persulfate and hydrogen peroxide for the removal of malathion was studied.
this study was carried out in laboratory scale and in batch flow reactors of steel which the low-pressure mercury vapor lamps of 55 watts was placed in it. The influence of parameters such as pH(3-9), H2O2(1-8Mm/l), perslfate dose(0.01-0.05 gr/l), and malathion (1-60 mg/l) was investigated. The malathion concentration in solution has been determined with the HPLC.
the results of this study showed that the discussed process has high efficiency in compare with other done studies, so that in optimum conditions – pH=3, concentration of persulfate 0.03 gr, consumed hydrogen peroxide 3mM and initial concentration of malathion 30mg/l – this process after 30 and 60 minutes, removed respectively 99.94% of malathion and 88.31% of COD.
photocatalytic process with persulfate and hydrogen peroxide as one of the advanced oxidation process alternatives has a high potential in reducing pollution load of different industries, including manufacture of pesticides and can be effective as a method for wastewater treatment and reduce the environmental problems.