粉末活性炭对水中五氯酚的吸附效果研究及模型建立

Adsorption of Pentachlorophenol from Aqueous Solution onto Powdered Activated Carbon

在一定温度和pH值范围内,40mg/L的粉末活性炭对于1mg/L的五氯酚超纯水溶液具有很好的吸附效果,吸附1h后基本达到平衡,五氯酚的去除率达到92%以上。建立的新吸附扩散模型不仅适用于其他吸附剂,而且优于一般的一级吸附模型。研究结果显示:粉末活性炭对低浓度五氯酚的吸附规律符合Radke-Prausnitz公式;活性炭投加过量时吸附效果无明显改善;水温从10℃升至30℃时吸附量变小,水温从30℃升至50℃时吸附量反而增大;五氯酚超纯水溶液剩余浓度与pH值成指数模型关系。吸附机理为五氯酚中苯环的π-π键间作用力与静电作用力共同作用的结果。

In spite of different pH and temperature in the aqueous solution, 40 mg/L PAC is enough for the 1 mg/L PCP aqueous solution. Adsorption equilibrium will finish within 1 h, and 92% PCP from aqueous solution will be removed. The adsorption diffusion model deduced from the theory is not only suitable for other adsorbents, also better than normal first-order adsorption model. The absorption law of low concentration of PCP absorbed by PAC is accord with Radke-Prausnitz formula . When the quantity of PAC is more than 40 mg/L, the adsorption effect doesnt become better or even bad.. When the temperature is changed from 10 ℃ to 30℃, the adsorption capacity will increase, while it will decrease when the temperature is changed from 30℃ to 50℃. The residual PCP in the aqueous solution is exponential to pH. The adsorption mechanism is the results of the PCP π-π interaction and static repulsive force is the most important force to adsorb PCP from the aqueous solution.