没食子药渣生物炭对苯酚的吸附

Adsorption of Phenol on Biochar in Residues of Gallnut

以没食子药渣为原料,采用限氧热解法制备了不同温度300℃、400℃、500℃、600℃下的药渣生物炭,考察pH、投加量、溶液温度、不同接触时间和溶液初始浓度对吸附苯酚的影响。实验结果表明,这几个因素均能影响生物炭对苯酚的吸附效果。4种不同热解温度制备的生物炭对苯酚的吸附能力为400℃>500℃>600℃>300℃,300℃和400℃最佳pH为5.0,500℃~600℃的最佳pH为7.0,药渣生物炭吸附苯酚的最佳投加量为0.05 g。在25℃~45℃条件下,较高的温度有利于药渣生物炭对苯酚溶液的吸附。没食子药渣生物炭的吸附过程先快后慢,在10 h趋于平衡。利用Langmuir和Freundlich模型对4种生物炭进行拟合,发现不同热解温度的药渣生物炭基本符合Langmuir和Freundlich等温吸附模型。研究结果为预测药渣生物炭吸附重金属提供理论参考,从而为拓展药渣资源化利用提供有效途径。

The biochar was prepared from the residues of Gallnut by limited oxygen pyrolysis at different temperatures of 300℃,400℃,500℃and 600℃.The effects of pH,dosage,solution temperature,contact time and initial concentration on phenol adsorption were investigated.The experimental results show that all these factors can affect the adsorption of phenol on biochar in residues.The order of adsorption capacity of biochar prepared at four different pyrolysis temperatures for phenol is 400℃>500℃>600℃>300℃.The optimal pH at the temperatures of 300℃and 400℃is 5.0,from 500℃to 600℃is 7.0.The optimal dosage of phenol adsorbed by biocharis 0.05 g.Under the condition from 25℃to 45℃,the higher the temperature,the better the adsorption of phenol on biochar in residues.The adsorption process of biocharin residues of Gallnut is fast and then slowly,it goes to balance at 10 h.The simulation results that the adsorption process of the four kinds of biochar with different pyrolysis temperature all basically conform to Langmuir and Freundlich isotherm adsorption models.This study provides theoretical reference for the adsorption of heavy metals by biochar in drug residue,as well as an effective way for expanding the utilization of drug residue.