磁性山竹壳炭的制备及对氯霉素吸附性能

Preparation of biochar based on magnetic mangosteen shell and its adsorptiontowards chloramphenicol

以山竹壳为原料,K_(2)C_(2)O_(4)为活化剂,Fe(NO_(3))_(3)为赋磁剂制备了磁性山竹壳炭。考察了制备条件对山竹壳炭理化性质的影响,并探究其对水体中氯霉素的吸附性能。结果表明,随着K_(2)C_(2)O_(4)用量的增加和炭化温度的升高,磁性山竹壳炭的比表面积和孔容增加,但Fe3O4逐渐被还原为单质Fe。当磁性山竹壳炭PGC-4-900投加量为0.3 g·L^(-1),溶液质量浓度为125 mg·L^(-1)时,对氯霉素吸附容量最大可达316.3 mg·g^(-1)。吸附过程为自发、吸热和无序度增加的过程。吸附动力学符合拟二级动力学模型,等温模型可用Langmuir方程描述。磁性山竹壳炭在吸附氯霉素方面具有宽泛的pH适应性,静电作用非磁性山竹壳炭对氯霉素吸附主要机理,孔隙填充和π—π作用在氯霉素吸附过程中起主导作用。

Mangosteen shell were chosen as raw material for preparing magnetic biochar via K_(2)C_(2)O_(4)activation and Fe(NO_(3))_(3)magnetization.The influences of preparation conditions on the physical and chemical properties of biochar were investigated,and its adsorption performance towards chloramphenicol(CAP)was also studied.Results showed that the specific surface area and pore volume of magnetic activated biochar increased with the increase of Carbonization temperature and dosage of K2C2O4,but Fe3O4 was gradually reduced to elemental Fe.When the dosage of PGC-4-900 was 0.3 g·L^(-1),and the CAP solution concentration was 125 mg·L^(-1),the adsorption capacity towards CAP could reach 316.3 mg∙g^(-1).The CAP adsorption process by the biochar was a spontaneous,endothermic,and randomness increase one.CAP adsorption process on the biochar could be well fitted with pseudo-second order kinetics and Langmuir models.Magnetic mangosteen shell biochar had a wide pH adaptability during CAP adsorption.Pore filling andπ-πinteraction were the main mechanisms for CAP removal by magnetic biochar of mangosteen shell,while electrostatic effect could be ignored.