荞麦秸秆生物炭对尼泊金乙酯的吸附特性研究

Adsorption characteristics of ethylparaben using buckwheat straw biochar

为促进荞麦秸秆的资源化利用,以荞麦秸秆为原料,采用慢速热解技术在300、400、500℃条件下制备荞麦秸秆生物炭吸附剂(分别记为BC300、BC400、BC500),检测其去除废水中尼泊金乙酯的效果。吸附试验结果表明,荞麦秸秆生物炭的制备温度能显著影响其对尼泊金乙酯的吸附效果,三种温度制备的荞麦秸秆生物炭对尼泊金乙酯的吸附能力表现从高到低依次为:BC500、BC400、BC300。此外,溶液中尼泊金乙酯的初始浓度、吸附温度和时间等因素均能对吸附效果产生影响。45℃下,尼泊金乙酯初始浓度为20mg/L时,BC500对尼泊金乙酯的去除率最高,达98.0%。荞麦秸秆生物炭对尼泊金乙酯的等温吸附线符合Langmuir模式和Freundlich模式。研究结果探明了荞麦秸秆制备生物炭吸附剂去除尼泊金乙酯的最适条件,以期为荞麦秸秆应用于尼泊金乙酯等有机污染物的去除提供参考。

The buckwheat straw was used as raw material to prepare the biochar adsorbent at 300,400 and 500℃,which were named BC300,BC400 and BC500,respectively.Ethylparaben was subject to batch adsorption in waste water by the prepared buckwheat straw biochar.The results of adsorption experiments showed that the preparation temperature of biochar significantly affected its adsorption effect of ethylparaben.The order of adsorption capacity of three kinds of biochar for ethylparaben from high to low was BC500,BC400 and BC300.In addition,the initial concentration of ethylparaben in waste water,the temperature and time of adsorption could also affect the adsorption effect.When the initial concentration of ethylparaben was 20 mg/L and the adsorption temperature was 45℃,the removal rate of ethylparaben was up to 98.0%by BC500 adsorption.The isothermal adsorption line for ethylparaben conformed to the Langmuir mode and Freundlich mode.The results showed the optimal condition of ethylparaben removal from waste water by buckwheat straw biochar,and provided basis for the removal of organic pollutants such as ethylparaben.