| The application of coal gasification techniques has significant role to relieve the dwindling supply of natural gas in China. However, the coal-gasification process could produce a large amount of wastewater with high content of phenolic compounds, polycyclic aromatic hydrocarbons, ammonium, cyanide, sulfide and a variety of refractory and toxic compounds. Phenols are high toxic and difficult biodegradable organic matter in industrial wastewater, but they are also basic raw materials of organic chemical and engineering. The phenolic compounds in the wastewater can be reused by resin adsorption. Accordingly, treatment of coal-gasification wastewater by resin adsorption will have significance for social, environmental and economical benefit.In this study,5 kinds of resin were used to adsorb phenols from high concentration phenol wastewater and HPD-950 was chosen as the best adsorbent.The phenol adsorption process of HPD-950 could reach equilibrium in 1 hour and was limited by both particle diffusion and film diffusion; The adsorption process of phenol and resorcinol were spontaneous and exothermic, and both fit to Langmiur equation and Freundlich equation; The adsorption kinetics of phenol and resorcinol on HPD-950 conform to the first-order dynamic equation; Phenol and resorcinol would adsorbed competitively in solution. The existent of NH4+ was benefit for phenol adsorption on resins while the existent of sulfide and oil was adverse for the phenol adsorption.In the study of dynamic adsorption it was found that lower flow rate, less concentration and higher resin bed height were good for the adsorption.The best flow rate was 6BV/h and the best height-diameter ratio of resin bed was around 10:1.6 kinds of desorption agent were used to regenerate HPD-950 resins. The desorption capacity were acetone>80% alkaline ethanol>alkaline liquid>ethanol>methanol >80% ethanol.80% alkaline ethanol were used as desorption solution and desorption flow rate was 5BV/h. The adsorption efficiency of the resin was above 97.5% after they were regenerated 6 times.The HPD-950 resin was used to treat coal-gasification wastewater. The results showed that the effect of pH value on the remove of phenols in wastewater was not significant by HPD-950 resin. When resin bed height-diameter ratio was approximately 10:1, the removal efficiency of total phenol in high concentration coal-gasification wastewater filtered was higher than 95% at 6BV/h flow at normal temperature. The resin could be regenerated by 3BV of 80% alkaline ethanol with 1BV of water in the flow of 5BV/h. |
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