磁性水热炭对水体中砷、氟的吸附特性

Adsorption characteristics of arsenic and fluoride in water by magnetic hydrothermal carbon

利用水热法合成磁性水热炭(m-HTC)吸附剂,经X-射线衍射仪(XRD)、Zeta电位分析仪对吸附剂进行表征,通过试验探究吸附剂对水体中砷、氟的吸附特性.结果表明:投加量为2 g·L^-1时,对砷、氟去除率达85%左右;去除率随pH变化而变化,随离子强度Is,吸附质初始质量浓度C0的增加而下降;不同温度下的等温线数据更符合Langmuir模型,温度升高有利于吸附,单独体系下砷、氟的最大吸附量qm分别为26.06和15.64 mg·g^-1,共存体系下对砷、氟的qm分别为20.42和13.62mg·g^-1,砷、氟存在相互抑制的作用;动力学试验数据更符合准二级动力学方程,经5次循环,去除率下降,但从实际角度,具有可取性.

Magnetic hydrothermal carbon(m-HTC)was prepared by hydrothermal synthesis method and characterized by X-ray diffraction(XRD)and Zeta potential and molecular weight analyzer.The adsorption properties of m-HTC to arsenate and fluoride in water were investigated by experiments.The results show that the removal rate of arsenic and fluorine reaches about 85%when the dosage is 2 g·L^-1.The removal rate is changed by pH and decreased with the increasing of I s and C 0.The adsorption isotherms are well fitted by Langmuir model at different temperatures,and increasing temperature is favorable for adsorption.The maximum removal capacities of arsenic and fluoride are 26.06 mg·g^-1 and 15.64 mg·g^-1 under the single system with 20.42 mg·g^-1 and 13.62 mg·g^-1 under the coexistence system,respectively.Arsenic and fluorine inhibit each other in coexistent solutions.The pseudo-second-order model is the best for predicting the adsorption kinetics.After five times of recycles,the removal rate of arsenic and fluorine is decreased,while it has advantages from practicality.