黑臭河道中聚乙烯醇/海藻酸钠固定微米沸石粉去除氨氮

Removal of Ammonia Nitrogen from Polyvinyl Alcohol/Sodium Alginate Fixed Micron Zeolite Powder in Black and Smelly Rivers

采用聚乙烯醇和海藻酸钠对微米沸石粉进行固定,通过批次吸附实验探究水凝珠去除氨氮的效果及其机制.结果表明:PAZ-20的投加量超过10 g·L^(-1)时,氨氮去除率达到了80%之上.pH为3~8时,pH增加对PAZ吸附氨氮影响不大,当pH从9增至11时,氨氮去除率随pH的增大而显著减小,PAZ吸附氨氮的最佳pH为7.水温为5~25℃时,氨氮去除率随温度升高而逐渐上升,25~35℃内略有上升,水温升至40℃,氨氮去除率有所下降.准二级动力学方程和Langmuir吸附等温线模型能够更好地拟合PAZ吸附氨氮.PAZ-20对于水中阳离子的吸附能力为:K+>Mg^(2+)>Na+>Ca^(2+).共存阳离子对PAZ吸附氨氮的影响程度为:K^(+)>Na+>Ca^(2+)>Mg^(2+).扫描电镜和傅里叶红外光谱分析显示微米沸石粉被良好地固定在聚乙烯醇/海藻酸钠中.PAZ可用于黑臭河道的治理,且受共存阳离子的干扰较小.

Using polyvinyl alcohol and sodium alginate to fix micron zeolite powder,the effect and mechanism of ammonia nitrogen removal by water beads were explored through batch adsorption experiments.The results showed that when the dosage of PAZ-20 exceeded 10 g·L^(-1),the ammonia nitrogen removal rate reached above 80%.When the pH was 3-8,the increase in pH had little effect on the adsorption of ammonia nitrogen by PAZ.When the pH increased from 9 to 11,the removal rate of ammonia nitrogen decreased significantly with the increase in pH.The optimal pH for PAZ adsorption of ammonia nitrogen was 7.When the water temperature was 5-25℃,the removal rate of ammonia nitrogen gradually increased with the increase in temperature,and it rose slightly within 25-35℃.When the water temperature rose to 40℃,the removal rate of ammonia nitrogen decreased.The quasi-second-order kinetic equation and Langmuir adsorption isotherm model could better fit the PAZ adsorption of ammonia nitrogen.The adsorption capacity of PAZ-20 for cations in the water was K^(+)>Mg^(2+)>Na+>Ca^(2+).The order of the effect of coexisting cations on the removal of ammonia nitrogen from PAZ-20 was K+>Na+>Ca^(2+)>Mg^(2+).The results of Scanning Electron Microscopy and Fourier Infrared Spectroscopy showed that the micron zeolite powder was well fixed in polyvinyl alcohol/sodium alginate.PAZ could be used for the treatment of black and smelly rivers with little interference from coexisting cations.