制革污泥生物炭对废水中亚甲基蓝的吸附性能研究

Study on the Adsorption Performance of Tannery Sludge Biochar Towards Methylene Blue from Wastewater

以制革污泥为原料,在氮气氛围下,控制热解温度在300~700℃范围内,制备了污泥基生物炭(TSBC),并研究了其对亚甲基蓝染料(MB)的吸附效果及机理。结果表明,500℃下热解得到的生物炭TSBC_(500),比表面积最大,为40.98 m^(2)/g,其平均孔径是9.21 nm,且表面存在大量-OH、-COOH等含氧官能团。相较于其他温度热解得到的生物炭,TSBC_(500)对MB的吸附去除率最高。吸附行为符合拟二级动力学模型与Langmuir热力学模型,吸附过程为主要受化学吸附控制的单分子层吸附。TSBC_(500)对MB的最大吸附容量可达76.34 mg/g。结合FTIR分析发现,TSBC_(500)对MB的吸附主要是静电作用、氢键作用、离子交换和π-πEDA等共同作用的结果。

Tannery sludge was used as raw material to prepare the biochar(TSBC)by traditional pyrolysis method under a nitrogen atmosphere,and the adsorption performance and mechanism of TSBC were studied using methylene blue(MB)as model pollutant.The results indicated that the properties reached the maximum at 500℃.The specific surface area and average pore diameter of TSBC_(500)were 40.98 m^(2)/g and 9.21 nm,respectively,and a large number of oxygen-containing functional groups such as-OH and-COOH were formed on the surface.Compared with the TSBC obtained under other pyrolysis temperatures,TSBC_(500)showed the superior removal efficiency of MB(92.3%),and the maximum adsorption capacity reached up to 76.34 mg/g.Besides,the adsorption process of MB was in accordance with a pseudo-second-order kinetics and the Langmuir isotherm well.Combined with FTIR analysis,the adsorption mechanism of TSBC_(500) on MB was mainly dependent on the electrostatic attraction,hydrogen-bond interaction,ion exchange,π-πEDA.