Preparation Of Cobalt Modified Carbon Materials And Its Degradation Effects On Typical PPCPs

As a class of emerging organic pollutants, Pharmaceutical and personal care products(PPCPs) have been widely concerned and detected in recent years. Though the concentrations of PPCPs in aqueous environment are low, they still have potential risks to ecosystem and human body due to its pseudo-persistence and bioaccumulation. Conventional water treatment processes are not effective for the PPCPs removal. Therefore, other effective water treatment processes should be explored to remove these contaminants. The technique of supported Fenton catalysis is an effective approach to degrade organic pollutants. In this paper, cobalt modified carbon materials were prepared for degradation of thalidomide and miconazole nitrate by activating sodium peroxydisulfate(PDS). The main conclusions were as follows:(1) Cobalt modified ordered mesoporous carbon(Co/ OMC) was prepared by OMC, which was synthesized by soft template method. The obtained materials were characterized by thermo gravimetric analyzer(TGA), X-ray diffraction(XRD),nitrogen adsorption-desorption techniques and transmission electron microscopy(TEM). The results showed that: A. F127 could be removed completely in the process of OMC synthesis when the temperature was 700?, and the calcination temperature of Co/OMC was 600 ?. B. Co/OMC still had good order and two-dimensional channel structure after modified, and the order decreased with the increase of the cobalt addition. C. the specific surface area of OMC was reduced from 676 m2·g-1to652 m2·g-1, but pore size changed inconspicuously. D. cobalt species existed in Co2O3 form and dispersed uniformly on the OMC substrateon.(2) The tests of degradation of thalidomide by Co/OMC indicated that: PDS actived by Co/OMC had excellent degradation ability to thalidomide at room temperature, and the higher temperature could accelerate the degradation removal, the thalidomide removal rate was 97.6% after 120 min at room temperature under the conditions of the concentration of thalidomide was 20 mg/L, the initial pH of 3, PDS dosage of 100 mg/L, Co/OMC dosage of 100 mg /L, the degradation could be described as the first order dynamic model well, Co/OMC had good catalytic activity,and could be well reused.(3) The prepared wood powder active carbon(AC) was modified with cobalt,and the characteristics of AC modified by different cobalt precursor(cobalt dichloride and cobalt nitrate) were studied with XRD and nitrogen adsorption-desorption techniques. The results showed that, the Co/AC-N modified by cobalt nitrate had larger specific surface area and bigger pore size. The cobalt on Co/AC-Cl modified by cobalt dichloride had larger particle size and could block the pore. CoO and Co2O3 were the forms of Co species on the Co/AC-N, and Co3O4 existed on the Co/AC-Cl with large particle size.(4) The tests of degradation removal of miconazole nitrate indicated that: the degradation of miconazole nitrate by Co/AC-Cl was faster, but the cobalt leaching was serious. It was harmful to environment and could not be well reused. Co/AC-N had good catalytic activity, and could be well reused. The orthogonal experiments indicated that, the most important factor about degradation was the initial pH, the degradation rate of miconazole nitrate was 97.2% under room temperature at condition of pH=3.0 within 120 min when the dosage of Co/AC was 500 mg/L and PDS was 200 mg/L.