Effective adsorption of prothiofos (O-2,4-dichlorophenyl O-ethyl S-propyl phosphorodithioate) from water using activated agricultural waste microstructure

Abstract

Pesticides were not only detected as pollutants in water but also having dangerous effect to human health. The dangerous effect comes from its metabolites because it has more toxicity than the parent compound. Prothiofos was degraded in water onto 2,4-dichlorophenol, O-2,4-dichlorophenyl O-ethyl hydrogen phosphorothioate and O-2,4-dichlorophenyl O-ethyl hydrogen phosphate. Here, the agriculture wastes (orange peel and apricot kernel) have been used as inexpensive adsorbent for removal the pesticide prothiofos and its degradation compounds from aqueous solution. The effect of time, prothiofos concentration, pH and the adsorbent dose were tested in batch adsorption experiments. The results show that the uptake efficiency of prothiofos increased when the pH of adsorption system increased then decreased at pH greater than 7. The using of different adsorbent dosage showed that the 91.7 % and 86 % prothiofos removal was achieved when 5 g L−1 of the orange peel and apricot kernel, respectively. The maximum adsorption capacities were 185.9 ± 1.8 and 145.8 ± 2.4 mg g−1 for the orange peel and apricot kernel, respectively. The kinetic study indicates that the prothiofos removal with the selected adsorbents is a pseudo-second order adsorption. The adsorption data of prothiofos with the adsorbents were fitted with Langmuir and Freundlich isotherm model.