Preparation of sodium bicarbonate modified biochar and analysis of its adsorption mechanism for carbamazepine in water
This study used agricultural waste silk gourd complex powder as raw material and sodium bicarbonate as activator to prepare sodium bicarbonate modified biochar(SBC)that can efficiently adsorb carbamazepine(CBZ)in water through impregnation pyrolysis method.The physical and chemical characteristics such as surface morphology,pore size distribution,functional groups,and degree of graphitization are analyzed through characterization methods.The effects of temperature,dosage,pH and other factors on the adsorption of CBZ in water by SBC are studied through batch experiments.The results show that compared to the original biochar(BC),SBC has a higher specific surface area of 531.43 m2/g and a richer pore size structure.The effect of pH on the adsorption of CBZ by SBC is minimal,and SBC is almost unable to adsorb large molecular humic acids.The Sips model can better describe the adsorption equilibrium law of CBZ on SBC,with an adsorption capacity of 125.52 mg/g at 298 K.Thermodynamic analysis shows that the adsorption of CBZ by SBC is a spontaneous endothermic process,with physical adsorption being the main process.By analyzing the energy distribution of SBC sites and density functional theory,the enhanced adsorption mechanism of CBZ on SBC is further explored.The results show that hydrogen bonding,π-π electron acceptor donor,and pore filling are involved in the process of SBC adsorption of CBZ.Methanol can effectively regenerate saturated SBC,and after four adsorption desorption cycles,the adsorption capacity of SBC for CBZ remains at 68.132 mg/g.This article uses agricultural and forestry waste sponge gourd as a carbon source to prepare biochar for removing pollutants from water,providing a feasible approach to simultaneously achieve the resource utilization of agricultural waste and reduce environmental pollution.
biocharsodium bicarbonateadsorptioncarbamazepinesite energy distribution(SED)density functional theory(DFT)
NETL
NSTL
万方数据
