Adsorption Of Uranium(?) By Modified Coconut Biochar

With the rapid development of the nuclear industry,the demand for uranium is also increasing.Once such uranium-containing wastewater leaks,it will pose a major threat to the environment and human safety.Therefore,the search for reliable and economical methods of uranium removal is receiving increasing attention.In recent years,in response to national environmental protection policies,many agricultural and forestry residues have been better utilized to produce fuel through reuse.The use of coconut shell biochar in this test is one of these secondary reutilization forestry residues.The chemical modification of coconut shell biochar can change its specific surface area,void density,pore size distribution and the type and amount of oxygen-containing functional groups at the surface active sites.Thereby increasing its adsorption efficiency and adsorption amount.In this study,the coconut shell biochar was modified with oxidant KOH and KMnO₄ to obtain the adsorption effect of biochar on uranium???modified by KOH alone and KMnO₄&KOH.The adsorption test showed that KMnO₄&KOH modified coconut shell biochar?CBC-3?had the best uranium removal performance and studied the effects of different factors on uranium???removal,such as the amount of adsorbent,pH of solution,adsorption time,Initial solution concentration and temperature.The coconut shell biochar before and after modification was characterized by BET,Boehm,scanning electron microscopy and FT-IR/Fourier transform infrared spectroscopy.The adsorption process was further fitted by a kinetic model and a thermodynamic model,and the adsorption mechanism was analyzed by fitting data.The adsorption test results show that KMnO₄&KOH has the best effect on the modification of coconut shell biochar?CBC-3?.The optimum adsorption pH of the U???solution was 5,and the adsorption time was 48 hours.The adsorption capacities of CBC-3,CBC-2,and CBC-1 were 4.82mg/g,3.61mg/g,and 3.01mg/g,respectively.The adsorption process of uranium???by CBC-3,CBC-2and CBC-1 accords with the pseudo second-order dynamic equation theory and the Langmuir isotherm adsorption model.Thermodynamic analysis indicated that the adsorption was an endothermic reaction.