活性炭纤维在测定水中痕量苯酚与苯胺中的应用

发布时间：2018-01-15 22:31

  本文关键词：活性炭纤维在测定水中痕量苯酚与苯胺中的应用　出处：《苏州科技学院》2015年硕士论文　论文类型：学位论文

  更多相关文章： 活性炭纤维 苯酚 苯胺 富集

【摘要】：苯酚与苯胺在天然水体中浓度低,直接用光度法难以准确定量,在检测之前需要富集分离。萃取法需要消耗大量有机溶剂,污染环境,蒸馏法操作复杂,需要高温加热。吸附法是一种简单易行的富集方法,但寻找高效率的吸附材料是一个难点。课题用改性后的活性炭纤维(Actived carbon fiber,ACF)对水样进行富集分离,避免使用有机溶剂,简化富集操作过程,降低了检出限。课题首先用未改性的ACF和颗粒炭(Granular avtived carbon,GAC)对不同浓度水样做静态吸附实验,ACF的吸附效率比GAC高7%～17%。分析吸附等温线发现吸附过程更符合Freundlich模型。为提高富集效率,用磷酸和氯化钡分别对ACF进行改性处理并优化改性条件,对比两种方法的改性效果,结果表明150 mmol·L~(-1)的BaCl_2溶液浸渍12h制得的ACF_3对苯酚与苯胺的富集效率最高。分析吸附等温线发现ACF_3的吸附过程也更符合Freundlich模型。然后用ACF_3分别富集150μg的苯酚与苯胺,研究吸附时间、pH、吸附温度、ACF_3用量对富集效率的影响。确定苯酚的最佳富集条件为:吸附平衡时间110 min、pH为6、温度20℃、ACF_3用量为0.25 g,富集效率为98.74%;苯胺的最佳富集条件为:吸附时间为90 min、pH为7、温度20℃、ACF_3用量为0.15 g,富集效率为98.34%。对富集有150μg苯酚、苯胺的ACF_3分别进行脱附实验,用NaOH作苯酚的脱附剂,H_2SO_4作苯胺的脱附剂,研究脱附剂浓度、脱附温度对脱附效果的影响。通过实验确定,苯酚的最佳脱附条件为:NaOH浓度为2.5 mol·L~(-1)、脱附温度70℃,脱附率可达95.54%;苯胺的最佳脱附条件为:H_2SO_4浓度0.05mol·L~(-1)、脱附温度70℃,脱附率可达96.39%。最后在优化条件下,取距某印染厂排污口500、1000、1500 m处的下游河水并检测其中苯酚与苯胺的含量。苯酚的浓度依次为0.093、0.052、0.031 mg·L~(-1),回收率为94%～98%,检出限为0.004 mg·L~(-1)。苯胺的浓度依次为0.081、0.034、0.009 mg·L~(-1),回收率为94%～99%,检出限为0.002 mg·L~(-1),验证了ACF富集光度法测定水中痕量苯酚与苯胺的可行性。
[Abstract]:The concentration of phenol and aniline in natural water is low, the direct spectrophotometry is difficult to quantify accurately, the extraction method needs to consume a large amount of organic solvent, pollute the environment, and the operation of distillation method is complex. High temperature heating is needed. Adsorption is a simple and convenient enrichment method. However, it is difficult to find high efficient adsorption materials. The subject is to enrich and separate the water samples with modified activated carbon fiber (ACFs) and activated carbon fiber (ACFs). To avoid the use of organic solvents, the enrichment process was simplified and the detection limit was reduced. First of all, unmodified ACF and granular avtived carbon were used. GAC) for static adsorption of water samples with different concentrations. The adsorption efficiency of ACF is 7 / 17 higher than that of GAC. The adsorption isotherms show that the adsorption process is more in line with the Freundlich model. ACF was modified by phosphoric acid and barium chloride, and the modification conditions were optimized. The effects of the two methods were compared. The results show that 150 mmol 路L ~ (1). The concentration efficiency of phenol and aniline was highest in ACF_3 prepared by impregnating with BaCl_2 solution for 12 h. The adsorption isotherm analysis showed that the adsorption process of ACF_3 was more consistent with Freundlich mode. Then ACF_3 was used to enrich phenol and aniline at 150 渭 g. The effects of adsorption time (pH) and adsorption temperature (ACF3) on the concentration efficiency of phenol were studied. The optimum conditions of phenol enrichment were determined as follows: adsorption equilibrium time 110min pH 6, temperature 20 鈩，

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