玉米秸秆生物炭对甘肃农村窖水中氨氮的吸附特性及影响因素

采集兰州周边农田的废弃物玉米秸秆制备生物炭,研究了在不同吸附温度、pH值、氨氮浓度的条件下生物炭对窖水中氨氮的吸附影响。使用Langmuir和Freundlich等温方程分别对等温吸附实验数据进行拟合,并讨论其吸附机理。结果表明,制备生物炭的比表面积为60.8 m^2/g,平均孔径为2.204 nm;对氨氮的最佳吸附pH值范围为7～9;较为经济的生物炭投加量为11 g/L。吸附动力学拟合结果表明,准二级动力学能更好地拟合吸附过程;吸附等温线结果表明,Langmuir方程能更好地描述对氨氮的吸附行为;热力学结果表明,生物炭对窖水中的氨氮的吸附是自发的、放热的且以物理吸附为主。

The Biomass carbon was prepared by using waste corn stalks from Lanzhou, Gansu Province. The effects of biomass carbon on the adsorption of ammonia nitrogen in strontium water under different adsorption temperatures, pH values and ammonia nitrogen concentration were studied. The Langmuir and Freundlich isotherms were used to fit the isothermal adsorption experimental data and the adsorption mechanism was discussed. The results showed that the prepared biomass carbon had a specific surface area of 60.8 m^2·g^-1, an average pore diameter of 2.204 nm. The optimum adsorption pH for ammonia nitrogen ranges from 7 to 9;the economical biomass carbon dosage is 11 g/L. The adsorption isotherm results show that the Langmuir equation can better describe the adsorption behavior of ammonia nitrogen. The thermodynamic results indicate that the adsorption of ammonia nitrogen by the biochar on the sputum water is a spontaneous, exothermic, and physical adsorption-based process.