处理氮肥厂氨氮废水的树脂筛选及动力学特征

Screening and dynamics of resins in treating ammonia nitrogen wastewater of nitrogen fertilizer plant

采用上海汇脂树脂厂的3种强酸性阳离子交换树脂001×7,D61和D001,研究了树脂对模拟氮肥厂废水(氨氮、Ca2+,Mg2+的质量浓度分别为915,120,70mg/L)中氨氮的Freundlich和Lagergren吸附等温式,在30～50min内树脂对氨氮的吸附基本达到平衡,等温线均符合Freundlich模式,根据吸附等温模型,树脂结构特征和再生等评价方法筛选出用D61树脂去除该废水中的高浓度氨氮效果较好;并研究了D61树脂的动力学特征.结果表明:D61树脂对氨氮的吸附在初期快速反应阶段(前20min)既符合拟一级Lagergren反应动力学模型又符合拟二级Lagergren反应动力学模型,而整个过程理论分析采用拟二级Lagergren反应动力学模型较好,实际应用时采用拟一级Lagergren反应动力学模型速率较快,因而更具有实际意义.

Three strong acid cation exchange resins 001 ×7, D61 and D001 of Shanghai resin plant were adopted, the ammonia nitrogen in simulated nitrogen fertilizer plant wastewater （ammonia nitrogen 915 mg/L, Ca^2＋ 120 rag/L, Mg^2＋ 70 mg/L）adsorption isotherms were studied, the ammonia nitrogen adsorption balance was achieved within 30-50 rain, and the iso- therms were in line with Freundlich model. D61 resin was screened in removing high concentra- tion of ammonia nitrogen wastewater by the adsorption isotherm model, resin structural char- acteristics and regeneration evaluation methods; D61 resin dynamic characteristics were stud- ied. The results show that the process of ammonia nitrogen adsorption on D61 resin in initial rapid reaction phase（before 20 rain）is consistent with both pseudo-first and pseudo-second La- gergren react kinetic model; and the whole process adopts pseudo-second Lagergren react ki- netic model better on theoretical analysis, adopts pseudo-first Lagergren react kinetic model faster on practical application, which has more practical significance.