Experimental Research On The Electrochemical Remediation Of Carbamazepine Contaminated Soil

Carbamazepine?CBZ?is a common psychotropic drug,great harm to the human body.In this paper,the CBZ polluted soil was degraded by Fenton-electrolysis method,and the extraction,adsorption and desorption characteristics of soil CBZ were studied.Focus on the factors of influencing the conductance,such as electrode material,plate spacing,electrode Voltage,moisture content and conductivity,etc.And focus on Fenton advanced oxidation system factors,such as the amount of hydrogen peroxide,pH,ferrous ion dosage,etc.The degradation process of CBZ in soil by Fenton-electrolysis combined method was analyzed,and the suitable process parameters of CBZ degradation by Fenton-electrolysis method were obtained.This paper use the advanced organic oxidation principle,combined with electrolysis technology to remove CBZ in the polluted soil,the main conclusions are as follows:?1?For water and ethanol,methanol has the highest extraction efficiency for CBZ in soil.The extract solvent was methanol,extraction way was 30 minutes of ultrasonic extraction followed by 30 minutes of oscillation extraction under 25?,and the average efficiency of extraction was 88.45%.?2?The adsorption capacity of CBZ in soil was not strong.For soil and water ratio?1:10?,CBZ solution concentration was 1-5mg/L,soil CBZ adsorption capacity was 1.61-5.18mg/kg,and adsorption rate per unit soil 10.35% 16.05%.The desorption ability of CBZ in the soil is strong,for the soil CBZ adsorption capacity of 10-50mg/kg,soil to liquid ratio of 1:10,desorption rate can reach 80%.The time required for the adsorption and desorption to reach equilibrium is about 24 hours,the adsorption rate of the first 1 hour is the fastest,reaching more than 80% of the total adsorption capacity,and finally slowly adsorbed/desorbed to equilibrium.?3?In the process of electrolysis degradation of CBZ in the soil,the plate spacing has an important effect on CBZ removal.For the plate spacing range,the smaller the plate spacing,the higher the removal rate,the greater the degradation rate,the appropriate plate spacing of 2cm.There was no obvious correspondence between the electrode voltage and the removal of CBZ in the soil.The degradation rate of CBZ was faster at the voltage range of 2.5±0.5V.The water content has an important effect on the removal of CBZ in soil.The higher the water content is,the higher the CBZ removal rate is,the higher the degradation rate is,and the suitable moisture content is 40±5%.The conductivity is too low is not conducive to the removal of CBZ,increase the soil conductivity can improve the removal rate,but the soil conductivity is too high will lead to soil compaction,hinder the removal of CBZ,resulting in decreased removal rate,the appropriate conductivity of 5.3ms/cm The Under the same conditions,the use of graphite electrode on the soil CBZ degradation degree than the use of iron electrode.Based on the above conditions,the removal rates of sampling point?1?,?2?and?3?were 73.41%,91.8% and 38.18 respectively.?4?For the degradation of CBZ in water by Fenton method,there is an optimum initial concentration of H2O2,Fe2 + dosage,and pH.When the concentration of CBZ aqueous solution is 20mg/L,the optimum initial concentration of H2O2 is 0.66mol/L,the initial concentration of Fe²⁺ is 0.04mol/L,the optimum pH of the solution is 3.5±0.1,the removal rate is 99.9%.?5?For the degradation of CBZ in mud by Fenton method,there is an optimum initial concentration of H2O2,Fe2 + dosage,and p H,too.When the concentration of CBZ aqueous solution is 20mg/L,the optimum initial concentration of H2O2 is 1.056mol/L,the initial concentration of Fe²⁺ is 0.067mol/L,the optimum pH of the solution is 3.5±0.1,the removal rate is 99.9%.?6?For the soil contaminated by CBZ,when the soil CBZ adsorption capacity was 14.16mg/kg,the soil-to-water ratio was 1: 2,and the water retention time was 4h,after leaching of contaminated soil,64.6% CBZ was transferred to the water,when the initial concentration of H2O2 is 0.66mol/L,the initial concentration of Fe²⁺ is 0.04mol/L(the molar ratio of H2O2/Fe²⁺ is about 16.5: 1),The CBZ removal rate in the aqueous phase reached 99.9%.When the residual CBZ in the soil solid phase is treated by electrolysis,the electrode spacing is 2cm,the voltage is 2.5±0.5V,the water content is 40±5%,the CBZ removal rates were 50.7%,69.99% and 44.84% corresponding sampling point?1?,?2?,?3?in the soil,respectively.The removal rate of CBZ in soil by Fenton-electrolysis method can reach a high degree,and the total removal rate is 89.4%.