The Research Of Rapid Adsorption Of Pesticides 2,4-dichlorophenoxyacetic Acid By Iron Oxide Nanoparticles-doped Carboxylic Ordered Mesoporous Carbon

Pesticides are an integral part of modern agriculture, and greatly increase the output of grain production. But with the wide application of pesticide s, pesticides are distributed around the world and can be detected in the water on the earth. In addition, the pesticides have very long damping period and are difficult to degrade by nature itself and enriched continuously in the top of the organisms through the food chain, which aroused many problems of environmental pollution and incidents of pesticides poisoning, and destroyed the ecological balance of ecosystem, so people 's attention are increasingly focused on the environmental problems of pesticide pollution to and the impact on human health. Long exposure to environment contain pesticides will have serious adverse effects on humans and animals, and even produce the risk of cancer. Therefore, pesticide pollution treatment is imminent. We prepared iron oxide nanoparticles-doped carboxylic ordered mesoporous carbon(Fe/OMC), and investigated the adsorption process and mechanism of pesticide 2, 4-D on Fe/OMC in this study.The ordered mesoporous carbon composite functionalized with carboxylate groups and iron oxide nanoparticles(Fe/OMC) was successfully prepared and used to adsorb 2,4-dichlorophenoxyacetic acid(2,4-D) from wastewater. The resultant adsorbent possessed high degree of order, large specific surf ace area and pore volume, and good magnetic properties. The increase in initial pollutant concentration and contact time would make the adsorption capacity increase, but the p H and temperature are inversely proportional to 2,4-D uptake. The maximum adsorption was obtained at p H 3. It suggested that the 2,4-D adsorption was highly dependent on solution p H. The equilibrium of adsorption was reached within 120 min, and the equilibrated adsorption capacity increased from 99.38 to 310.78 mg/g with the increase o f initial concentration of 2,4-D from 100 to 500 mg/L. Notably, the adsorption capacity reached 97% of the maximum within the first 5 min. The adsorption capacity for 2,4-D decreased from 270.60 to 256.38 mg/g with the increase of the temperature from 30 to 50 ?C. The result indicated that the process of the adsorption was exothermal. The kinetics and isotherm study showed that the pseudo-second-order kinetic and Langmuir isotherm models could well fit the adsorption data. Adsorption thermodynamics model demonstrated that the adsorption of 2,4-D was mainly a physisorption process, and the adsorption process was feasible and spontaneous. The adsorption efficiency could still remain high after six cycles as to the high initial concentration of 2,4-D, which indicated that Fe/OMC had a good capacity of regeneration and repeatability. These results indicate that Fe/OMC has a good potential for the rapid adsorption of 2,4-D and prevention of its further diffusion.