Determination Of Trace Phenol And Aniline In Water With Actived Carbon Fiber

It's difficult to detect trace phenol and aniline in national water with spectrophotometric method directly, so enrichment and separation is essential. Extraction requires a large amount of organic solvents, which may lead to environmental pollution. Distillation requires high temperature heating, which is complex to operate. Adsorption is a simple and feasible method, but highly efficient adsorbent is hard to find. ACF was used for enrichment and separation of water samples to avoid using organic solvents, simplify the operation and decrease the detection limit.Firstly, water samples of different concentrations were adsorbed with ACF and GAC. The adsorption efficiency of ACF was 7%?17% higher than that of GAC. Analysis of adsorption isotherms showed that the adsorption process was more in line with the Freundlich model.In order to improve the efficiency of enrichment, ACF was modified by H3PO4 and BaCl₂, and the modified conditions were optimized. The results showed that the best conditions are : modifying agent(150 mmol�L^-1 BaCl₂), dipping time?12h?. The modified ACF was called ACF₃. Analysis of adsorption isotherms showed that the adsorption process of ACF₃ was more in line with the Freundlich model.Secondly, ACF₃ was used to enrich 150 ?g phenol and aniline respectively, and the effects of adsorption time, pH, temperature, and dosage of ACF₃ were studied. The optimal enrichment conditions of phenol are: adsorption equilibrium time?110min?, pH?6?, temperature?20 ??, dosage of ACF₃?0.25g?. Enrichment efficiency is 98.74%. The optimal enrichment conditions of aniline are: adsorption equilibrium time?90min?, pH?7?, temperature?20??, dosage of ACF₃?0.15g?. Enrichment efficiency is 98.34%.The desorption of ACF₃ was studied. The effects of concentration of desorption agent, desorption temperature were studied. The optimum desorption conditions for phenol were:desorption agent(2.5 mol�L^-1NaOH), desorption temperature?70??. The desorption rate is 95.54%. The optimum desorption conditions for aniline were:desorption agent(0.05 mol�L^-1 H₂SO₄), desorption temperature?70??. The desorption rate is 96.39%.At last, in the optimized conditions, the downstream water 500, 1000, 1500 meters away from the sewage outlet of a printing and dyeing factory was detected. The concentration of phenol was 0.093, 0.052, 0.031 mg�L^-1, the recovery rate was 94%?98%, the detection limit was 0.004 mg�L^-1. The concentration of aniline was 0.081?0.034?0.009 mg�L^-1, the recovery rate was 94%?99%, the detection limit was 0.002 mg�L^-1. The feasibility of using ACF to determine trace phenol and aniline in water was verified.