磷酸改性茶渣对荧光素钠的吸附性能研究

Adsorption Performance of H_3PO_4-modified Waste Tea Residiue for Fluorescein Disodium Salt

将茶叶废渣用H3PO4改性后作为吸附剂处理荧光素钠染料废水,为茶叶废渣的资源化利用提供了一条新的途径.本实验研究了吸附时间、吸附温度、荧光素钠浓度、p H值等不同条件下改性茶渣对荧光素钠染料的吸附性能的影响.结果表明,当荧光素钠溶液的p H值为3.7、温度为15℃时,改性茶渣对荧光素钠染料有很好的去除效果.改性茶渣对荧光素钠染料的吸附符合Langmuir、Freundlich等温模型,降低温度能够增加吸附剂对荧光素钠染料的吸附量,说明改性茶渣对荧光素钠染料的吸附是一个放热过程.吸附过程符合一级、二级吸附动力学方程.磷酸改性茶渣在实验最佳条件下的吸附量可达63.05 mg/g,而未改性茶渣的吸附量则为46.30 mg/g.磷酸改性茶渣比未改性原茶渣具有更好的吸附性能.

H3PO4-modified waste tea residue as an adsorbent is used in the treatment of fluorescein disodium salt dye wastewater, which provides a new way for the resource utilization of tea waste residue. Its adsorption properties for fluoreseein disodium salt dye were studied under different conditions such as the adsorption time, adsorption temperature, concentration of fluoreseein disodium salt and pH from aqueous solution. It was showed that the adsorbent has good removal efficiency for fluorescein disodium salt dye at pH 3.7 and 15℃. Its adsorption conforms to the Langmuir and Freundlieh isothermal model. Lower temperature can increase the adsorption of fluorescein disodium salt dye, which showed this adsorption is an exothermie process. The adsorption process fits first- order and second- order kinetic equation. The maximum adsorption capacity of fluorescein disodium salt by the unmodified waste tea leaves is 46.30 mg/g and H3PO4-modified waste tea leaves can reach up to 63.05 mg/g. It is found that H3 PO4-modified waste tea residiue has better adsorption for fluorescein disodium salt than the unmodified one.