聚丙烯酸/海藻酸钠基纳米二氧化钛(PAA/SA@TiO2)复合水凝胶对氨氮的吸附性能
Study on the adsorbing performance of ammonia nitrogen by polyacrylic acid-grafted sodium alginate-based titanium dioxide(PAA/SA@TiO2)composite hydrogel
郭昌梓 1韩义 1赵婉琴 1张旭立1
作者信息
- 1. 陕西科技大学环境科学与工程学院,西安,710021
- 折叠
摘要
聚丙烯酸/海藻酸钠基纳米二氧化钛(PAA/SA@TiO2)复合水凝胶对氨氮具有良好的吸附效果,其最佳吸附条件为:pH=7,温度 35℃,吸附剂用量 6 g·L-1,吸附平衡时间 70 min,当初始氨氮浓度分别为 100、200、300 mg·L-1 时,吸附效率分别为 85.56%、79.46%、67.63%.该吸附过程符合Langmuir模型的单层吸附,吸附动力学模型属于拟二级动力学模型的化学吸附.热重分析(TG)表明,PAA/SA@TiO2 复合水凝胶在 446℃主链断裂降解,羟基和羧基发生热分解,在 800℃时热损失率为48%.PAA/SA@TiO2 复合水凝胶结构稳定,经过 5次循环吸附再生后,吸附效率仅下降约 10%.研究结果表明PAA/SA@TiO2 复合水凝胶在含氮废水处理领域具有较好的应用前景,本研究为水凝胶应用于含氮废水处理提供理论依据和运行参数.
Abstract
The polyacrylic acid-grafted sodium alginate-based titanium dioxide(PAA/SA@TiO2)composite hydrogel showed excellent adsorption performance for ammonia nitrogen.The optimal adsorption conditions is pH=7,T=35℃,adsorbent dosage 6 g·L-1 and adsorption equilibrium time of 70 minutes.At that time,the adsorption efficiencies were 85.56%,79.46%and 67.63%for initial ammonia nitrogen concentrations of 100,200 and 300 mg·L-1,respectively.The adsorption process is the Langmuir model of monolayer adsorption,and the adsorption kinetics belongs to the pseudo-second-order kinetics model of chemical adsorption.Thermal gravimetric analysis(TGA)showed that the main chain,hydroxyl and carboxyl groups,of PAA/SA@TiO2 composite hydrogel began disrupting and degrading at 446℃with thermal loss rate of 48%at 800℃.The PAA/SA@TiO2 composite hydrogel possessed a stable structure,and the adsorption efficiency only decreased by approximately 10%after 5 cycles of adsorption and regeneration.The research indicated that the PAA/SA@TiO2 composite hydrogel had great potential in the nitrogen-containing wastewater treatment.The results provided theoretical basis and operational parameters for the application of hydrogels.
关键词
复合水凝胶/氨氮/吸附机理/性能表征/循环利用Key words
composite hydrogel/ammonia nitrogen/adsorption mechanism/performance characterization/recycling引用本文复制引用
基金项目
陕西省自然科学基础研究计划(2023-JC-YB-366)
出版年
2024
NETL
NSTL
万方数据