Mechanism Study Of Removing Chlorinated Hydrocarbons By Ironarbon Composites Via Ball Milling Preparation

Zero-valent iron is a kind of material frequently applied in soil and groundwater remediation.It is one of the hotspots of soil and groundwater remediation industry to seek a non-polluting,high-efficiency and simple preparation technology of iron-based material.As a new non-polluting and mass-produced preparation technology,more attention has been paid to the ball-milling preparation technology,while the research of the technology has not been systematically studied globally.In this study,the materials were applied to the degradation experiment of trichloroethylene based on the preparation of zero-valent iron materials with different ball milling times.The residual concentration value and intermediate products of trichloroethylene were detected to explore the degradation and ball milling mechanism by the ball milling process.On the basis of exploring the influence of ball milling parameters,the study further explored the factors that affect the degradation performance of iron-carbon composite materials,straw biochar calcined at different temperatures,wet milling or dry milling process,two-step ball milling method,etc.In this paper,the changes of the morphology and structure of the zero-valent iron particles during the ball milling process were verified by scanning electron microscopy and Malvern particle size analyzer.The infrared spectroscopy and X-ray photoelectron spectroscopy were used to illustrate the changes in the crystal form and surface functional groups of the ball milling process.The calculation of the removal rate and kinetics of the degradation experiment explored the effect of the ball milling process on the removal of trichloroethylene by zero-valent iron particles,and revealed that the effect of the ball milling process actually promoted the electron transfer rate of the reaction process.The experimental results showed that under the reaction conditions of this experiment,the reducing ability of the material obtained by ball milling has increased by 13%,and the reducing ability was the main improvement performance.In the exploration of iron-carbon composite materials,the experimental results proved that the adsorption performance of different types of biochar on trichloroethylene was different.The ball milling time of biochar in the entire ball milling process should not be too long,which would destroy the original pore structure of biochar.In addition to the influence factors,the ball milling method was also one of the primary influencing factors.The performance of the iron-carbon composite material obtained under wet grinding conditions was better than that of dry milled materials.The experimental results showed that the carbon carrier in the iron-carbon composite material has a gain effect on the total removal amount and removal rate.