Study On Removal Of Heavy Metals Cu(Ⅱ) And Pb(Ⅱ) In Wastewater By Magnetic Pomelo Peel-based Biochar

With the progress of society and the improvement of people’s living standards,a large number of pollutants have been released into the environment.The pollution of heavy metals to animals and plants and human health cannot be ignored.Due to the needs of industrial production,the exposure of heavy metals in the environment has only increased,and for the sake of human health,it is urgent to develop strong and effective heavy metal pollution technologies.Adsorption is a low-cost,high-efficiency,pollution-free and eco-friendly water pollution remediation technology.Therefore,the selection and preparation of adsorbents is the top priority for adsorption and removal of pollutants in wastewater.For a long time,the agriculture,forestry,fruit and vegetable industry has generated a huge amount of waste,and its application to the treatment of pollutants in water has also attracted researches’ attention in recent years.However,the treatment effect achieved by simply applying it to water purification is unsatisfactory.Modification of chemical reagents,pyrolysis to prepare carbon materials,and graft copolymerization to polymer materials can effectively improve the combination with water pollutants.This paper combines the agricultural waste pomelo peel produced in daily life as the research object,and aims to explore the feasibility of removing Pb(Ⅱ)and Cu(Ⅱ)in wastewater by using charcoal prepared with pomelo peel as the adsorbent raw material to prepare biochar Treatment of wastewater containing Pb(Ⅱ)and Cu(Ⅱ).The adsorption characteristics of magnetic biochar prepared by the combination of hydrothermal carbonization pretreatment method and the advantages of pyrolysis and biochar prepared by direct pyrolysis were studied and compared.The surface chemical characteristics of the two carbons were analyzed by SEM,FTIR,XRD and XPS,and the adsorption of Pb(Ⅱ)and Cu(Ⅱ)was simulated.The different conditions(p H,adsorption kinetics,adsorption isotherm)changes to explore the impact of the process.The pomelo peel magnetic biochar(MPPB)produced by advantages’ method of hydrothermal carbonization pretreatment coupled with the of pyrolysis showed stronger combination with Pb(Ⅱ)and Cu(Ⅱ)in wastewater than the FPPB,which prepared by direct pyrolysis.Binding capacity,the maximum adsorption value of MPPB(the maximum adsorption value for lead is 205.40 mg/g,the maximum adsorption value for copper is 81.90 mg/g)is almost twice that of FPPB(the maximum adsorption value for lead is 102.40 mg/g,the maximum adsorption value for copper is47.54 mg/g).Although MPPB has high metal binding ability,especially for Pb(Ⅱ),the removal of Cu(Ⅱ)needs to be improved.The BBD experimental design in RSM was used to optimize the influencing factors to remove MPPB and Cu(Ⅱ).In the experiment,the concentration of Cu(Ⅱ),the p H of Cu(Ⅱ)solution,and the amount of MPPB were selected as the influencing factors.Three levels were selected,and the removal of Cu(Ⅱ)was used as the response.Analyze and predict the optimal solution.The optimal solution was C0 = 60 mg/L,p H=6,and the amount of MPPB was 0.7 g/L for verification.It was observed that the Removal(Cu(Ⅱ))was 95.75%,and the adsorption amount was81.43 mg/g.(97.0078%)Approximate.The feasibility and accuracy of the experimental design of BBD in RSM in the removal of Cu(Ⅱ)by MPPB were demonstrated,and the most suitable conditions for absorbing Cu(Ⅱ)were also found.In summary,this study successfully prepared pomelo peel-based magnetic biochar,confirming its ability to effectively heavy metals,and provided a feasible solution for the application of pomelo peel as a pretreatment in water purification.Further study and analysis of the adsorption mechanism of Pb(Ⅱ)or Cu(Ⅱ)in MPPB adsorption wastewater,mainly through the XRD and FTIR characterization changes after MPPB adsorption,the comparison of XPS before and after adsorption,the common monovalent and bivalent in solution Effect of coexisting ions on MPPB adsorption process.After the adsorption of MPPB,the XRD and FTIR characteristics changed to different degrees,which indicates that the complexation occurred during the metal-MPPB binding process.In the combination of MPPB with the target solution(Pb(Ⅱ)or Cu(Ⅱ),the addition of monovalent and divalent cations has a negative effect on the adsorption process,and ion exchange occurs on the surface.It is concluded that possible mechanisms: the main mechanisms is electrostatic attraction and chemical complexation,which are assisted by ion exchange.