T-42树脂对沉钒废水中氨氮的动态吸附及解吸研究

Research on Dynamic Adsorption and Desorption of T-42 Resin on Ammonia Nitrogen in Vanadium Precipitated Wastewater

为了了解T-42树脂吸附沉钒废水中氨氮的效果及其再生性能,研究了离子交换柱高径比、初始氨氮浓度和串联级数对吸附效果的影响,分析了等温吸附模型。此外,还研究了解吸过程中解吸剂的种类、流速、解吸剂溶液浓度对氨氮解吸效果的影响。结果表明:①当废水的流速为9 mL/min,柱高径比为21.0时,T-42树脂对氨氮的吸附效果较好,穿透点吸附量为21.91 mg/g,吸附终点吸附量为34.31 mg/g;随着初始氨氮浓度的升高,吸附量升高,处理废水量降低;氨氮浓度为1 999.56 mg/L的废水经2级串联吸附后达到一级标准(≤10 mg/L)。②T-42树脂吸附氨氮符合Langmuir等温吸附模型,吸附过程为单分子层化学吸附,在15、25、35℃下T-42树脂对氨氮的理论饱和吸附量分别为36.845 9、38.550 5、40.617 4 mg/g,温度升高有利于树脂的吸附。③在解吸剂硫酸溶液体积浓度为18%,流速为3 mL/min,解吸剂溶液用量为2.67个床层体积时,对吸附饱和的树脂上氨氮的解吸率大于99%。T-42树脂可以有效地去除废水中的氨氮,并且硫酸可以对吸附氨氮后的树脂进行解吸再生。

In order to understand the adsorption effect on ammonia nitrogen in vanadium precipitated wastewater and the recycle ability of T-42 resin,the influence of ratio of height to diameter of ion exchange column,original ammonia nitrogen concentration and series number on adsorption effect were studied,and the isothermal adsorption curve of T-42 resin was analyzed.In addition,the effect of the type,flow rate and concentration of desorbents on ammonia nitrogen desorption were also studied.The results showed that:①The adsorption effect of T-42 resin on ammonia nitrogen was better when the flow rate of wastewater was 9 mL/min and the ratio of height to diameter was 21.0.The adsorption capacity at the penetration point was21.91 mg/g,and the adsorption capacity at the end point was 34.31 mg/g.The adsorption capacity of resin on ammonia nitrogen increases with original ammonia nitrogen concentration increasing,but the wastewater treated decreases.Wastewater with concentration of ammonia nitrogen 1 999.56 mg/L meets the standard Class One(≤10 mg/L)by two-stage series adsorption.②The adsorption of ammonia nitrogen by resin matches the Langmuir isothermal adsorption model and the adsorption process is single molecular layer chemical adsorption.The saturated adsorption capacity is 36.845 9 mg/g in 15℃,38.550 5 mg/g in 25℃,40.617 4 mg/g in 35℃.The increasing temperature is beneficial to the adsorption.③In the case of volume concentration of sulfuric acid 18%,flow rate 3 mL/min and desorbent dosage 2.67 bed volumes,the ammonia nitrogen desorption rate of adsorption saturated resin was higher than 99%.T-42 resin can effectively remove ammonia nitrogen from wastewater,and sulfuric acid can desorb and regenerate the resin which adsorbs ammonia nitrogen.