Preparation Of Electrolytic Manganese Residue Matrix Composite Adsorbent And Study On The Adsorption Properties Of Heavy Metals

Electrolytic Manganese Residues（EMR）is a kind of solid waste produced when electrolytic manganese is produced in electrolytic manganese industry.Due to the increasing demand for electrolytic manganese and the decrease of the grade of manganese ore in singulos annos,the total amount of electrolytic manganese residues in China is increasing,but most enterprises will pile up electrolytic manganese slag in the open air for a long time,which will not only cause a waste of land resources,but also pollute the surrounding environment.Therefore,it is of great practical significance to recycle and reduce electrolytic manganese residues.The discharge of heavy metals（HMs）industrial wastewater will cause serious water pollution phenomenon.Adsorption of HMs water treatment technology has become a relatively good method of water treatment due to the advantages of simple operation,but the cost of some adsorbents are more expensive,so the application is more difficult.Therefore,the development of a relatively cheap,efficient adsorbents is an important direction of HMs wastewater treatment at present.Electrolytic manganese residues（EMR）,as a solid waste composed of silicon,manganese,calcium,iron,oxygen and sulfur,can be modified into an adsorbent with high efficiency,which has a great potential to be made into an adsorbent.Therefore,the study on how to modify it can be used as a way of resource utilization of electrolytic manganese residues,and it is also a necessary and effective direction.It not only contributes to resource utilization and reduction of electrolytic manganese residues,but also uses waste to treat and adsorb heavy metals for environmental pollution treatment,which has a double effect.In this paper,EMR was selected to carry out different organic and inorganic modification to prepare three kinds of composite adsorbents,and the related exploration and mechanism exploration of the composite material’s heavy metal adsorption performance were carried out.The specific contents and conclusions are as follows:（1）Electrolytic manganese residues-serpentine composite adsorbent（S-EMR）This chapter mainly after mixing EMR and serpentine minerals modified production become a kind of composite adsorbent,by static adsorption equilibrium experiment and the initial solution p H,contact time,initial concentration and reaction temperatures experiments to explore the effects of the removal of Cd²⁺and Pb²⁺through the analysis of the characterization of the adsorbent and adsorbed adsorbent,discusses its adsorption mechanism.The results showed that when S-EMR adsorbed Cd²⁺and Pb²⁺,the optimal solution p H was 6.0 and 4.0,respectively.The adsorption of Cd²⁺and Pb²⁺on S-EMR was more in line with the quasi-second-order kinetic model and Langmuir model.When the temperature ranged from 30℃to 50℃,the adsorption capacity of Cd²⁺by S-EMR was from 98.00 mg/g to 115.29 mg/g,and the adsorption capacity of Pb²⁺was from 630.95 mg/g to 664.08 mg/g.There are three main adsorption mechanisms for Cd²⁺/Pb²⁺by S-EMR,namely surface precipitation,electrostatic attraction and ion exchange.（2）Electrolytic manganese residues-based polyacrylic acid composite adsorbent（P-EMR）In this chapter,EMR was organically modified into a compound adsorbent,and the effects of removing Cd²⁺and Pb²⁺were investigated by static adsorption equilibrium experiment,such as initial p H,contact time,initial concentration and reaction temperatures.The adsorption mechanism was explored through different characterization analysis.The results showed that when P-EMR adsorbed Cd²⁺and Pb²⁺,the optimal solution p H was 6.0 and 4.0,respectively.The adsorption of Cd²⁺and Pb²⁺by P-EMR was more consistent with the quasi-second-order kinetic model and Langmuir model.When the temperatures ranged from 30℃to 50℃,the adsorption capacity of Cd²⁺by P-EMR was from 66.69 mg/g to 72.37 mg/g,and the adsorption capacity of Pb²⁺was from 135.45 mg/g to 149.32 mg/g.The adsorption of heavy metal ions by P-EMR is mainly chemisorption,which specifically includes chelation or coordination,ion exchange,interaction between functional groups（i.e.groups containing O and N）,Si-O and Al-O and heavy metal ions.（3）Electrolytic manganese residues-based-serpentine-polyacrylic acid composite adsorbent（S-PEMR）This chapter mainly combine the EMR and serpentine,and organic modification to make it become a kind of composite adsorbent,by static adsorption equilibrium experiment and the initial solution p H,contact time,initial concentration and reaction temperatures experiments to explore the effects of the removal of Cd²⁺and Pb²⁺through the analysis of the characterization of the adsorbent and adsorbed adsorbent,explore its adsorption mechanism.The results showed that when P-EMR adsorbed Cd²⁺and Pb²⁺,the optimal solution p H was 6.0 and 4.0,respectively.The adsorption of Cd²⁺and Pb²⁺by S-PEMR was more consistent with the quasi-second-order kinetic model and Langmuir model.When the temperatures was from 30℃to 50℃,the adsorption capacity of Cd²⁺on S-PEMR was from 128.36 mg/g to 148.92 mg/g,and the adsorption capacity of Pb²⁺was from 175.57 mg/g to 294.61 mg/g.The adsorption of heavy metal ions by S-PEMR is mainly chemisorption,which specifically includes chelation or coordination,ion exchange,interaction between functional groups（i.e.groups containing O and N）,Si-O and Al-O and heavy metal ions.