Effects of dissolved oxygen and surfactant treatment on the sorptive capacity of a local soil for phenol

The soil used in this study was found to have 24% clay (Muscovite) and a su rface area of 173 m(2)/g. H exadecyl-trimethyl-ammonium bromide (HDTMA) sur factant was mixed with the soil in order to investigate its effect on the s oil sorptive capacity. Fourier transform infrared spectroscopy (FTIR) spect rums showed interaction between the soil and HDTMA. Phenol adsorption isoth erms conducted for the soil under different combinations of HDTMA and disso lved oxygen (DO) revealed that both HDTMA and DO enhance the adsorption cap acity of the soil for phenol. HDTMA-induced increase of 48.5% and 312% in t he soil sorptive capacity was attained at a residual phenol concentration o f 100 g/l under anoxic and oxic conditions, respectively. On the other hand , DO increased the soil sorptive capacity by 26% and 249% at 100 mg/l pheno l residual concentration for untreated and treated samples, respectively. T he sorptive capacity enhancement was investigated at different residual phe nol concentrations. DO without HDTMA treatment caused a constant enhancemen t around 40%. Up to a residual phenol concentration of 240 mg/l, DO caused an additional capacity enhancement over that treated with HDTMA only. Above the aforementioned residual concentration, an opposite trend was observed.