The Study About The Effect Of Electric Field On Cu²⁺ Fixing By K₂FeO₄ In Soil

Soil is a place where nature regulated and adjusted its procedures.It can not only provide moisture and nutrients for crops,and we live on the basis of the terrestrial ecosystem.It is related to our daily food security,agricultural product safety,sustainable development of agriculture and social harmony and stability.With the high speed development of economy,we also brought serious soil pollution.Therefore,rational utilization of soil and control pollution soil is the duty of our current and burden.Potassium ferrate has a good fixation on heavy metals in soil,but potassium ferrate has a higher cost.In order to save the cost,the electrode intervention is adopted.The purpose of this study was to investigate the electric field have effect on K2FeO4 fixing Cu²⁺ in soil,and to study the relationship between redox potential?Eh?and soil adsorption stability.The main research contents are as follows:?1?The effect of the dosage of potassium ferrate,voltage,initial concentration of copper ion,pH value and electrode material on the flocculation of copper ion in water under the "medicine + electricity" mode was studied.?2?The mechanism of flocculation of copper ions in water under the "medicine +electricity" mode was studied,and the feasibility of "medicine + power" model was validated.Laid a foundation for the fixed experiment of copper in the soil.?3?The effect of potassium ferrate dosage,voltage,ionic strength,pH value on the adsorption of copper in soil was studied.?4?The reaction mechanism of adsorption and immobilization of Cu²⁺ in soil under the "medicine + electricity" mode was studied.?5?The heavy metals in the soil were fixed under the "drug + electricity" model,and the effects of these three factors on the desorption of copper ions in the soil were studied by leaching with different p H,temperature and Cr⁶⁺.?6?The redox potential of the soil was calculated by using the redox system(Fe3+/Fe²⁺)in the soil,and the relationship between redox potential and adsorption stability was discussed.The conclusions:Flocculation experiments of copper ions in water:?1?With the increase of the dosage of potassium ferrate,the removal rate of copper ions was also increased.When the dosage of potassium ferrate was 8mg,the removal rate of copper ions was 63.5% with stewing 30 min.?2?The voltage value was bigger,the removal rate of Cu²⁺ was better.?3?The pH value had little effect on the flocculation of copper ions when it was more than 5.5.?4?The experiment verified the feasibility of " medicine + electricity" model.Adsorption of copper ions in soil:?1?When the potassium ferrate was not added to the potassium ferrate,the adsorption capacity of the soil to the copper ion was 0.304mg/g,and the adsorption capacity of the soil to the copper ion was 0.392mg/g when the dosage was 0.25 g.Potassium ferrate greatly enhanced the adsorption of copper ions.?2?In the voltage of 8V,whether or not the total copper adsorbed copper or copper adsorption near the anode and cathode near the little difference,but when the voltage is 20 V,the anode copper and cathode copper is up to 0.125mg/g.?3?In the absence of NaCl,the change of copper ions in the soil after electrolysis is not very large,and the migration is not occurred.?4?When the pH value was 11,the migration of copper ions in the soil was smaller.Desorption of copper ions in soil:?1?When pH=5.6,the desorption of copper contaminated liquid for 0.152mg/g,adding copper contamination and potassium ferrate solution for 0.123mg/g desorption,desorption and adding copper contamination and potassium ferrate solution and electrolysis experiments for 0.097mg/g.?2?REDOX potential is higher,the greater the stability of the soil heavy metal is fixed.?3?After added the Cr⁶⁺ contamination,the desorption of Cu²⁺ increased significantly,and the higher the concentration of Cr⁶⁺ solution,the greater the amount,but when the concentration of Cr⁶⁺ was higher than 75 mg,the desorption was not significantly increased.