丙烯酸改性壳聚糖磁性颗粒处理模拟废水中氨氮

以去除水产养殖废水中的氨氮，寻找安全快速高效的吸附剂为目的。以壳聚糖为原料制备丙烯酸改性壳聚糖磁性颗粒，采用单因素及正交实验方法优化制备条件，研究振荡吸附条件对吸附量的影响，进行吸附等温模型和吸附动力学研究。结果表明，最佳制备条件，丙烯酸4 mL、磁流体0.75 g、过硫酸铵1 g、戊二醛1.5 mL；最佳吸附条件，废水pH值5~9、吸附剂浓度3 g/L、吸附时间10 min；吸附过程符合二级动力学模型，以化学吸附为主；液膜扩散为限速步骤；氨氮最大吸附量为77.16 mg/g，远高于其他传统吸附剂。研究表明，丙烯酸改性壳聚糖磁性颗粒对模拟水产养殖废水的氨氮去除效果显著，具有很好的应用前景。

Ammonia nitrogen removal from simulate wastewater by acrylic acid-modified magnetic chitosan particles

The objective of this work is to find a safe,fast and efficient adsorbent which can remove ammonia nitrogen of the aquaculture wastewater. Using the natural polymer chitosan as the material to prepare the adsorbent:acrylic acid-modified magnetic chitosan particles. The preparing condition of the acrylic acid-modified magnetic chitosan particles was optimized by single factor experiment and orthogonal experiment. Aslo the adsorption condition of ammonia adsorbed adsorbent in the thermostatic shaker was investigated. Then the adsorption isotherrnal model and the adsorption dynamics were researched. The results shows that the optimum preparation conditions were 4 mL of acrylic acid,0.75 g of ferrofluid,1 g of ammonium persulphate,1.5 mL of glutaraldehyde. The optimum adsorb conditions were pH range of 5~9,the adsorbent concentration of 3 g/L,the adsorption of ammonia nitrogen can reach equilibrium in 10 min. The adsorption kinetics shows that the adsorption process can fit the second-order kinetics model well,which can indicate the process of adsorption mainly is chemisorption. According to the moving boundary model,we can draw a conclusion that the liquid film diffusion is the mainly rate-limiting step.The adsorption isotherm obeys to the Longmuir equation,and the calculated maximum adsorption capacity of ammonia nitrogen to 77.16 mg/g. The acrylic acid-modified magnetic chitosan particles can remove the ammonia nitrogen remarkably, showing that it is a promising adsorbent.