Preparation Of Transportable Carbon Materials And Their Application In Activating Persulfate

Nowadays,the pollution of soil and groundwater is becoming more and more serious.Compared with the pollutants in water and atmosphere,the treatment of pollutants in soil and groundwater is more complex and difficult.The in-situ chemical oxidation method based on persulfate oxidation system is the current research hotspot,showing a certain application prospect.However,the transferability of activator in the oxidation system is poor,and it cannot effectively diffuse in soil.In this study,a new oxidation system of persulfate activated by underground carbon nanospheres was proposed.Based on the preparation of a new type of underground persulfate activator,the performance of the system for in situ treatment of organic pollutants in soil was investigated,and the reaction mechanism was further revealed.In this study,a hydrothermal carbon sphere with controllable particle size was prepared by hydrothermal method using glucose as precursor.Carboxylated carbon materials were obtained by carbonizing hydrothermal carbon at high temperature and a series of acid-alkali reactions.By further simulating underground transport experiments,it is proved that the dispersibility of activated carbon materials is significantly higher than that of pre-activated carbon materials.Scanning electron microscopy analysis shows that activated carbon has a stretching vibration peak.The particle size ranges from 100 nm to 1 m,which meets the requirements of underground transmission.X-ray photoelectron spectroscopy showed that carboxylation increased the C=O ratio from 0.18 to 0.57.Subsequently,using Rhodamine B and tetracycline as substrates,the removal ability of carbon materials was tested.The removal ability of carbon materials with the highest degree of carboxylation was 90% for Rhodamine B except adsorption,and 88% for tetracycline.In addition,the experiment found that the C=O group had a certain correlation with the reaction rate constant.It was inferred that the catalytic active site was C=O group.The reaction principle was further explored.At the same time,the peak shapes and proportions of the active substances produced were compared by EPR spectroscopy.It was determined that the oxides in the system were singlet oxygen,which was different from the hydroxyl radicals and sulfate radicals in the traditional persulfate oxidation system.