Abstract
In this paper, batch removal of diazinon and 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous solution by granular-activated carbon was investigated. The required concentrations of toxins were prepared by appropriate dilution of the stock standard solution. There was a significant relationship between chemical oxygen demand (COD) and toxins concentration and that COD was measured instead of direct analysis of toxins. For all the concentrations tested, removal efficiency increased by increasing contact time for both toxins. The highest removal efficiency of 90% for 2,4-D and 88% for diazinon obtained in 50-min contact time. The highest value of toxin removal for both toxins occurred at pH=6. Based on the results obtained, one can conclude that granular-activated carbon has high efficiency in 2,4-D and diazinon removal from aqueous solution.