Preparation Of Biomass-based Magnetic Carbon Material And Study On Its Arsenic Removal Performance

With the rapid development of China’s industry,water treatment is facing huge challenges and threatening the security of water resources.Residents of villages and towns in China mainly use groundwater as a source of drinking water,and arsenic pollution often occurs and has a huge impact on people’s health.Arsenic(As)is a ubiquitous toxic metal element that exists widely around us.It has carcinogenic,teratogenic and mutagenic properties.Xinjiang is also in a high arsenic area,so the control of arsenic pollution is even more necessary.Among the various removal technologies,iron oxides are popular because of their wide source and low toxicity.Iron oxide has a strong binding capacity with arsenic,but iron oxide is easy to agglomerate,resulting in a decrease in specific surface area and thus affecting adsorption efficiency.Therefore,the matrix is used as the base of the iron oxide to increase the dispersibility of the iron oxide and improve the adsorption efficiency.In recent years,there are a lot of people consider biomass materials,because the use of biomass can not only reduce pollution but also can be used to remove pollutants.Two common preparation methods,solvothermal method and co-precipitation method,were successfully used to prepare magnetic carbon materials.The results of applying the prepared magnetic carbon materials to batch arsenic removal experiments are as follows:(1)Magnetic carbon material(MC)was prepared by solvothermal method,and its adsorption was studied using simulated arsenic waste liquid.The prepared MC was subjected to structural characterization and As(V)removal experiments,and the removal conditions under conditions such as the activation ratio,the amount of adsorbent added,the reaction time,and p H were investigated.The mechanism of arsenic removal by MC was investigated.Batch experiments show that the adsorption efficiency under acidic conditions is better than that under alkaline conditions.The adsorption process is compatible with the Langmuir model and the pseudo-second-order kinetic model.It has a high removal rate of arsenic and can reach international standards of less than 10 μg/L for 2 mg/L arsenic solution.The effect of anions coexisting in water on the efficiency of arsenic removal was studied.The results showed that phosphate had a greater effect on the removal of arsenic.Through mechanism research,the removal of arsenic by MC is mainly attributed to the reaction between the oxygen-containing functional group on the surface of biochar and arsenic ions and the complexation reaction between iron oxide and arsenate ions.(2)Magnetic carbon material(MB)was successfully prepared by co-precipitation method,and batch experiments were performed using simulated arsenic wastewater,such as Effect of activation ratio,different adsorption dose,reaction time,p H,etc.on arsenic removal efficiency.The results of batch experiments show that MB has a good ability to remove arsenic and can be recycled.The adsorption process of arsenic ions conforms to the Freundlich model and the pseudo-second-order kinetic model.(3)Considering the practical application,a fixed-bed adsorption column experiment was carried out to investigate the penetration curves under the flow rate,the amount of adsorbent,different column lengths,and different initial arsenic ion concentrations.The experimental results show that a low flow rate of 0.5 m L/min and a high column 10 cm,the adsorbent dosage is 0.2 g,which is more beneficial to the removal process of arsenic ions.