尿素改性生物质炭吸附水中氨氮研究
发布时间：2018-09-03 10:34
【摘要】：利用尿素对小麦秸秆生物质炭进行改性,用于吸附水中氨氮。研究了尿素添加量、pH、改性生物质炭投加量、共存阳离子等因素对改性生物质炭吸附氨氮的影响,并研究了吸附的热力学和动力学机制。结果表明,1.00g未改性生物质炭中添加2.4g尿素时制备得到的改性生物质炭UBC-4对氨氮吸附能力最好,零电荷点相比改性前明显降低。处理20mL 60mg/L的氯化铵溶液,UBC-4最佳投加量为0.20g,最适pH为8。实际废水处理中应考虑Na+、Mg2+等共存阳离子对UBC-4吸附氨氮的竞争吸附作用。Langmuir方程能较好地拟合UBC-4对氨氮的吸附等温过程,准二级动力学模型能较好地描述其动力学过程。吸附为自发的吸热过程,主要机制是物理吸附。
[Abstract]:Wheat straw biomass carbon was modified by urea to adsorb ammonia nitrogen in water. The effects of pH of urea, dosage of modified biomass carbon and co-existing cations on the adsorption of ammonia nitrogen by modified biomass carbon were studied. The thermodynamic and kinetic mechanisms of adsorption were also studied. The results showed that the modified biomass carbon (UBC-4) prepared by adding 2.4 g urea to unmodified biomass carbon had the best adsorption capacity for ammonia nitrogen, and the zero charge point was obviously lower than that before modification. The optimum dosage of UBC-4 in ammonium chloride solution treated with 20mL 60mg/L is 0.20 g and the optimum pH is 8. In practical wastewater treatment, the competitive adsorption of UBC-4 to ammonia nitrogen by co-existing cations such as Na and mg _ 2 should be considered. Langmuir equation can fit the isothermal process of UBC-4 adsorption of ammonia nitrogen well, and the quasi-second-order kinetic model can describe the kinetic process well. Adsorption is a spontaneous endothermic process, and the main mechanism is physical adsorption.
【作者单位】： 西北大学城市与环境学院;
【基金】：国家自然科学基金资助项目(No.51208424) 城市水资源与水环境国家重点实验室开放基金面上基金资助项目(No.QA201318) 陕西省重点科技创新团队计划项目(No.2014KCT-27) 陕西省环境保护专项基金资助项目
【分类号】：X703
，
本文编号：2219728
[Abstract]:Wheat straw biomass carbon was modified by urea to adsorb ammonia nitrogen in water. The effects of pH of urea, dosage of modified biomass carbon and co-existing cations on the adsorption of ammonia nitrogen by modified biomass carbon were studied. The thermodynamic and kinetic mechanisms of adsorption were also studied. The results showed that the modified biomass carbon (UBC-4) prepared by adding 2.4 g urea to unmodified biomass carbon had the best adsorption capacity for ammonia nitrogen, and the zero charge point was obviously lower than that before modification. The optimum dosage of UBC-4 in ammonium chloride solution treated with 20mL 60mg/L is 0.20 g and the optimum pH is 8. In practical wastewater treatment, the competitive adsorption of UBC-4 to ammonia nitrogen by co-existing cations such as Na and mg _ 2 should be considered. Langmuir equation can fit the isothermal process of UBC-4 adsorption of ammonia nitrogen well, and the quasi-second-order kinetic model can describe the kinetic process well. Adsorption is a spontaneous endothermic process, and the main mechanism is physical adsorption.
【作者单位】： 西北大学城市与环境学院;
【基金】：国家自然科学基金资助项目(No.51208424) 城市水资源与水环境国家重点实验室开放基金面上基金资助项目(No.QA201318) 陕西省重点科技创新团队计划项目(No.2014KCT-27) 陕西省环境保护专项基金资助项目
【分类号】：X703
，
本文编号：2219728
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