Study On The Adsorption And Stabilization Of Lead And Nickel By Modified Hami Potassium Feldspar

The pollution of heavy metal lead and nickel has serious harm to the natural environment and the human body.It is the focus of the current research to seek the economic and effective treatment methods.Because of wide material source,processing advantages adsorption method has become a research hotspot.The potash feldspar mineral resources is rich in Xinjiang,but its application to is mostly concentrated in the glass and ceramic industry and the extraction of potash fertilizer in agriculture.In this paper,potassium feldspar in Hami,Xinjiang is used as raw material to deal with heavy lead and nickel polluted water and soil environment through Zinc Oxide modification,and to investigate the influencing factors of adsorption,in order to provide references for Xinjiang potassium feldspar mineral resources in environmental pollution control of heavy metals,lead and nickel.The main conclusions are as follows:（1）The potassium feldspar raw materials was modified by Zinc Oxide and the modification conditions were optimized,powder X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）and specific surface area instrument were used to characterized the potassium feldspar,analysis of the phase composition,surface morphology and the specific surface area.The results show that Zinc Oxide has been successfully loaded on potassium feldspar,the surface morphology has become rough,and the connectivity between particles has been strengthened,and the pore structure and specific surface area have been increased.After modification,the specific surface area of BET reached 64.242 m²·g^-1,which was 13.29 times higher than that of unmodified potassium feldspar 4.609 m²·g^-1.Through the specific surface area analysis,we know that the specific surface area and Kong Rong data of original potassium feldspar is less.After modification,the two data have been greatly improved,which is more conducive to the adsorption of Ni²⁺and Pb²⁺.（2）The modified and unmodified potassium feldspar were used to adsorb lead wastewater,and the content,initial lead ion concentration of the solution,pH and adsorption time were preliminary studied on the adsorption effect,different adsorption isotherm models,dynamics models as well as thermodynamic properties were studied in the process of Pb adsorption by modified potassium feldspar.The results showed that:with the increase of potassium feldspar,the adsorption capacity showed a downward trend,and the removal rate increased.The solution pH had a significant effect on the adsorption effect,and the adsorption adsorption equilibrium is basically reached at 250 min.The experimental results showed that at25℃,content of 0.5 g,p H=5,adsorption time 250 min,20 m L concentration were 800 mg·L^-1,the removal rate after modification was 26.65%higher than that of unmodified potassium feldspar.The fitting of isothermal equation is more consistent with the Freundlich adsorption equation.The fitting of kinetic data is more consistent with pseudo two level kinetic model.Thermodynamic data analysis shows that the adsorption process of lead ion is a spontaneous endothermic reaction process mainly based on physical adsorption.（3）The adsorption experiments of modified feldspar on simulated nickel wastewater were carried out.The influence of different factors on the adsorption effect was studied.Meanwhile,the different isothermal adsorption models,different kinetic models and thermodynamic properties of adsorption process were also studied.The experimental results showed that at 25℃,content of 0.4 g,pH=6,adsorption time 250 min and 20 mL concentration were 500 mg·L^-1,the removal rate after modification was 27.05%higher than that of unmodified potassium feldspar.The fitting of isothermal and kinetic data can be found that the adsorption process is more consistent with the Langmuir isothermal equation and pseudo two order kinetic equation.The thermodynamic fitting data can be found that the adsorption of Ni²⁺on the modified potassium feldspar is spontaneous.The adsorption effect of different adsorbents on Ni²⁺has been compared.It indicates that the modified potassium feldspar can stabilize Ni²⁺to some extent.（4）The form of lead and nickel in different concentrations in the soil were analyzed,the mainly form of lead and nickel in the soil were different,The residue state（RF）content of lead is the highest in the tested soil,and the main three forms of nickel are residue state（RF）,iron and manganese oxide binding form（Fe-Mn）and organic matter（OM）.The data analysis shows that the exchangeable form（EX）and carbonate binding form（CARM）of lead and nickel are reduced after applying different modified potassium feldspar.With the increase of cation exchange capacity after the modification of potassium feldspar,the heavy metal lead and nickel of the exchangeable form（EX）and carbonate binding form（CARM）in the tested soil may be fixed by the modified potash feldspar,thus reducing the harm of heavy metal lead and nickel to the environment.It is proved that applying a certain amount of modified potassium feldspar in the tested soil can reduce the harm of heavy metal lead and nickel in the soil.