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| 竹炭交联壳聚糖铜对低温水中氨氮
的去除研究 |
| Experimental study on ammonia adsorption by modified bamboo charcoal crosslinking chitosan copper in low temperature water |
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| DOI： |
| 中文关键词: 竹炭交联壳聚糖铜 低温低浊水 氨氮 吸附 密度泛函理论 |
| 英文关键词: modified bamboo charcoal crosslinking chitosan copper NH3-N low temperature and low turbidity water Adsorption DFT |
| 基金项目:城市水资源与水环境国家重点实验室开放研究基金项目资助计划(2015TS07);哈尔滨商业大学博士科研启动基金资助项目(92508941);寒冷地区海绵城市跨季连续实施策略及其关键技术研究资助项目(HC201621-02) |
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| 摘要点击次数: 2629 |
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| 中文摘要: |
| 为了解决北方低温低浊水中的超标氨氮和去除难度大的问题,利用吸附法,以硝酸改性竹炭与戊二醛交联壳聚糖铜为原料,用5%的海藻酸钠交联法控制反应条件,制备出竹炭壳聚糖铜吸附剂.通过SEM,IR和BET对材料的形貌、结构、比表面积和化学组成等物化性能进行表征.通过其对水中氨氮(NH3-N)的静态吸附试验,考察其对氨氮的吸附效果及吸附规律,并利用密度泛函理论模拟吸附过程,推断竹炭交联壳聚糖铜对氨氮的吸附机理.结果表明,当吸附剂的用量为1 g/L,pH值为8,温度为5 ℃,吸附时间为80 min,搅拌速度为165 r/min,初始氨氮浓度为5 mg/L时,氨氮的去除率可以达到80%左右,基本达到了国家的生活饮用水对氨氮的浓度要求.其中竹炭交联壳聚糖铜的比表面积为157.78 m2/g,主要以微孔吸附为主,且微孔占总孔比表面积的90%以上,改性效果较好.将酸改性竹炭作为基体可使戊二醛交联壳聚糖的六元环骨架变强,碳网平面更加坚固,同时铜离子对氨氮具有化学螯合作用,更有益于对氨氮的吸附.吸附剂对氨氮的吸附符合拟一级动力学模型.密度泛函理论揭示了竹炭的协同作用一方面提高了对氨氮的吸附量,另一方面也促进了吸附的稳定性. |
| 英文摘要: |
| The adsorbent of modified bamboo charcoal crosslinking chitosan copper was optimized by making modified bamboo charcoal and crosslinking chitosan copper under 5% sodium alginate to remove ammonium in low temperature and low turbidity water. The physico-chemical properties of the as-prepared modified bamboo charcoal crosslinking chitosan copper, such as morphology, structure, surface area, and chemical composition were characterized by SEM, IR and BET. The adsorption capability and rules of NH3-N in aqueous solutions were tested in the static system. Adsorption mechanism of ammonium on modified bamboo charcoal crosslinking chitosan copper had been studied by DFT Simulation. The results showed that the adsorption optimum conditions were pH value of 8, ammonium concentration of 5 mg/L, temperature of 5 ℃, and stirring speed of 165 r/min, adsorbent amount of 1 g/L, the removal rate was over 80%. The specific surface areas of modified bamboo charcoal crosslinking chitosan copper were 157.78 m2/g,in the main of micropore adsorption,which made up to over 90% of total pores. The six membered ring of the amine portion on crosslinking chitosan copper were strengthen and stable. Hydroxide radical, amino of chitosan reacted with “d” orbit of copper, forming stable mesh unit structure; the reason of the ammonium removal lied in that ammonium reacted with copper to form copper ammonia complex ion. The adsorption kinetics of NH3-N by modified bamboo charcoal crosslinking chitosan copper followed the pseudo-first-order model. Density functional theory(DFT)showed that the synergistic effect of bamboo charcoal not only enhanced the adsorption capability of NH3-N, but also promoted the stable of adsorption. |
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