Dependence of sorption of phenoxyacetic herbicides on their physico-chemical properties

The purpose of this study is to assess the efficiency of removal of phenoxyacetic pesticides from water by means of activated carbon sorption. The sorbents used in this study (WD-extra, CWZ-22, NP-5) were produced by GRYFSKAND, Ltd., Hajn–wka. The first step of the study was the steady-state test of the suitability of selected sorbents in herbicide removal. The steady-state test was conducted according to the Chemviron Carbon methodology. Its aim was to determine the Freundlich isotherm and sorption capacity, and to select the best sorbent in static conditions. The residual concentration of the contaminant in the filtrate was determined using relevant analytical techniques. Also, the concentration of phenoxyacetic acid was identified by TLC and HPLC methods. On the basis of the results obtained it was concluded that the best sorbents of phenoxyacetic acid from water in steady-state conditions are CWZ-22 and NP-5. No significant difference was noticed in the removal process of the whole group of phenoxyacetic acids by sorption.