水葫芦生物炭对水溶液中Cu^(2+)的吸附研究

Adsrtlon of Cu^(2+) from Aqueous Solution with Biochaarderived from Eihhornia Crassipes

以水葫芦为原料制备生物炭,研究了不同生物炭用量、溶液pH、吸附时间及Cu^(2+)初始浓度条件下的吸附特性,并探讨了吸附机理.结果表明,当Cu^(2+)浓度为200mg·L^(-1)时,生物炭适宜用量为5g·L^(-1),Cu^(2+)的去除率可达97.2%.溶液pH值在2~7范围内,Cu^(2+)的最佳吸附pH值为5.生物炭对Cu^(2+)的吸附速度较快,在2h内达到平衡,吸附过程符合准二级动力学方程.等温吸附曲线可用Langmuir等温吸附模型拟合,最大吸附量为49.0mg·g-1.水葫芦生物炭对Cu^(2+)的吸附以作用力更强的专性吸附为主,特别是在吸附未达到饱和时,专性吸附比率高达98%以上.水葫芦生物炭对Cu^(2+)具有较强的吸附性能,是一种很有潜力的金属离子吸附剂.

In this study,the biochar was made from Eichhornia crassipes. The effect of adsorbent dosage,solution pH,adsorption time and initialcontent on the adsorption process was investigated and the adsorption mechanism was discussed. The results indicated that,when the initial concentration of Cu（2＋）was 200mg·L（-1）,the suitable dosage of biochar sorbentwas 5 g·L（-1）,and the removal rate of Cu（2＋）could reach 97. 2%. The best adsorption of Cu（2＋）was pH value 5in the range of 2 ～ 7. The velocity of adsorption to Cu（2＋）was quick and reached to adsorption equilibriumin 2 hours,and the adsorption process fitted well with pseudo- second- order kinetic models. The maximal adsorption capacities of the biochar to Cu（2＋）calculated from Langmuir isotherm equation,which were 49. 0 mg·g- 1. The adsorption of Cu（2＋）by the biochar was mainly the specific adsorption; especially when the adsorption did not reach saturation,the specific adsorption ratio was more than 98%. The biochar derived from Eichhornia crassipes hada strong adsorption with Cu（2＋）,and it was a potential metal ion adsorbent.