热解温度对茶树枝生物炭性能及其对铅、镉吸附能力的影响OA

Lead(Pb)and cadmium(Cd)have caused severe threats to aquatic environments due to industrial activities and the development of efficient and cost-effective adsorbent materials is an urgent task.In this study,tea tree branches,an agricultural waste,were used as the raw material to prepare biochar at different pyrolysis temperatures(300℃,400℃,and 500℃).The surface characteristics of the biochar were characterized using scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and X-ray diffraction(XRD)techniques.Adsorption kinetics and isotherm experiments were conducted to investigate the adsorption properties and mechanisms of biochar towards Pb2+and Cd2+.The results showed that the pyrolysis temperature significantly influenced the structural characteristics and adsorption performance of the biochar.As the pyrolysis temperature increased,the alka-linity and heavy metal adsorption capacity of the biochar were notably enhanced.The biochar prepared at 500℃ exhibited the best adsorption performance,with maximum adsorption capacities for Pb2+and Cd2+of 33.09 mg·g-1 and 6.28 mg·g-1,re-spectively.Kinetic analysis revealed that the adsorption process of the biochar was mainly controlled by chemical adsorp-tion,and the Langmuir isotherm model provided the best fit for the adsorption data.Adsorption mechanism studies indicated that the biochar primarily removed heavy metals through a mineral precipitation mechanism.In conclusion,this study demonstrates the promising application potential of tea tree branch biochar for the removal of Pb2+and Cd2+from aqueous solutions,providing new insights for the resource utilization of agricultural waste and the development of low-cost,effi-cient water treatment materials.