开心果壳活性炭对含Cr(Ⅵ)废水吸附性能及其吸附热动力学研究
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摘要
对开心果壳制备的生物质活性炭吸附剂,采用ZnCl_2活化,研究其对Cr(Ⅵ)吸附效果。通过批次实验,研究了活性炭对废水中Cr(Ⅵ)吸附的影响因素,如溶液pH、吸附剂用量、接触时间和溶液的初始浓度、吸附热动力学等。结果表明:开心果壳活性炭的BET的比表面积达1677.61 m~2·g~(-1),孔径约为29.73 nm的介孔结构,活化能约为4.39 kJ·mol~(-1);室温下,开心果壳活性炭投入量为1.25 g·L~(-1)、吸附90 min、模拟含Cr(Ⅵ)溶液初始浓度0.8 mmol·L~(-1)、pH值=2时,吸附效果最佳,Cr(Ⅵ)去除率在80%以上。采用微量热法研究了在最佳吸附条件下,开心果壳活性炭吸附Cr(Ⅵ)离子的热动力学性质,得到了该过程活化能为Ea=4.39 kJomol~(-1),吸附温度308.15K时,速率常数k=3.269×10~(-3)/s。
Activated carbon absorbent were prepared from pistachio nut shells by using ZnCl_2 as activating agent,and the influencing factors,such as pH,adsorbent dosage,initial Cr(Ⅵ) concentration and contact time and so on were investigated.The results showed that the surface area of BET was 1677.61 m~2·g~(-1),the average pore diameter of 29.73 nm,Ea = 4.39 kJ·mol~(-1),the removal rate at temperature of Cr(Ⅵ) was above 80% under the following conditions :pH=2,the dosage of 1.25 g·L~(-1),the initial concentrations of 0.8 mmol·L~(-1),adsorption equilibrium time of 90 min with good regeneration ability and reusability.The thermal kinetic properties of the adsorption of Cr(Ⅵ) ions on the activated carbon under the optimum adsorption conditions were studied by microcalorimetry.The activation energy of the process is Ea=4.39 kJ·mol~(-1) and the optimum adsorption temperature is 308.15 K with k=3.269×10~(-3)/s.
Activated carbon absorbent were prepared from pistachio nut shells by using ZnCl_2 as activating agent,and the influencing factors,such as pH,adsorbent dosage,initial Cr(Ⅵ) concentration and contact time and so on were investigated.The results showed that the surface area of BET was 1677.61 m~2·g~(-1),the average pore diameter of 29.73 nm,Ea = 4.39 kJ·mol~(-1),the removal rate at temperature of Cr(Ⅵ) was above 80% under the following conditions :pH=2,the dosage of 1.25 g·L~(-1),the initial concentrations of 0.8 mmol·L~(-1),adsorption equilibrium time of 90 min with good regeneration ability and reusability.The thermal kinetic properties of the adsorption of Cr(Ⅵ) ions on the activated carbon under the optimum adsorption conditions were studied by microcalorimetry.The activation energy of the process is Ea=4.39 kJ·mol~(-1) and the optimum adsorption temperature is 308.15 K with k=3.269×10~(-3)/s.
引文
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[15] 王琛,叶正芳,赵泉林.活性焦吸附处理对硝基苯甲酸废水[J].环境工程学报,2016,10(7):3545-3550.
[16] 陈虹霖,宋磊.不同活化方法对开心果壳活性炭的孔结构影响[J].华侨大学学报(自然科学版),2014,35(5):558-563.
[17] Hacer Dolas,Omer Sahin,Cafer Saka,et al.A new method on producing high surface area activated carbon:The effect of salt on the surface area and the pore size distribution of activated carbon prepared from pistachio shell[J].Chemical Engineering Journal,2011,166:191-197.
[18] 高胜利,陈三平,胡荣祖,等.化学反应的热动力学方程及其应用[J].无机化学学报,2002,18(4):362-366.
[2] 李江兵,夏明,丁纯梅,等.酸改性活性炭对废水中六价铬吸附效果的研究[J].环境与健康杂志,2013,30(1):69-71.
[3] 鲁秀国,黄燕梅,曹禹楠.改性核桃壳对Cr(Ⅵ)的吸附[J].化工环保,2015,35(1):74-78.
[4] 常爱香,安燕,胡鸣鸣,等.改性核桃壳处理含Cr(VI)废水的效果[J].南方农业学报2016,47(2):267-272.
[5] 肖轲,徐夫元,降林华,等.含Cr(VI)废水处理研究进展[J].北京师范大学学报(自然科学版),2016,52(1):76-82.
[6] 郭玉凤,崔建升,李景印,等.伯胺N1923反应萃取含Cr6+废水的研究[J].环境科学与技术,2003,26(5):15-18.
[7] 高欢韦,安磊,郑晓青,等.乙酰化小麦秸秆吸附水中六价铬[J].环境工程学报2016,10(9):4753-4760.
[8] 马欢欢,马叶,周建斌.载铁改性活性炭对溶液中六价铬[Cr(VI)]的吸附研究[J].科学技术与工程,2017,17(9):91-96.
[9] 聂兰玉,陈海,白智勇.羟基氧化铝吸附去除六价铬[J].环境工程学报,9(8):3847-3853.
[10] 鲁秀国,黄燕梅,曹禹楠.氨基改性核桃壳对废水中Cr(VI)的静态吸附研究,2014,30(6):491-98.
[11] 张双杰,邢宝林,黄光许,等.柚子皮水热炭对六价铬的吸附[J].环境工程学报,2017,11(5):2731-2737.
[12] 汪洋,吴缨.改性油菜秸秆对Co(Ⅱ)的吸附[J].环境工程学报,2016,10(1):379-384.
[13] 唐然肖,李妍,范胜男,等.核桃壳粉对阳离子染料结晶紫的吸附特性[J].河北大学学报(自然科学版),2018,30(3):254-261.
[14] 刘晓东,李沅,熊杰.改性玉米秸秆对铜离子的吸附性能[J].大连工业大学学报,2018,37(2):100-104.
[15] 王琛,叶正芳,赵泉林.活性焦吸附处理对硝基苯甲酸废水[J].环境工程学报,2016,10(7):3545-3550.
[16] 陈虹霖,宋磊.不同活化方法对开心果壳活性炭的孔结构影响[J].华侨大学学报(自然科学版),2014,35(5):558-563.
[17] Hacer Dolas,Omer Sahin,Cafer Saka,et al.A new method on producing high surface area activated carbon:The effect of salt on the surface area and the pore size distribution of activated carbon prepared from pistachio shell[J].Chemical Engineering Journal,2011,166:191-197.
[18] 高胜利,陈三平,胡荣祖,等.化学反应的热动力学方程及其应用[J].无机化学学报,2002,18(4):362-366.