Wang Sheng-Hua, Zhu Dan-Chen, Shao Jing-Ai, Xiang Jia-Tao, Yang Hai-Ping, Yi Juan, Zhang Shi-Hong, Chen Han-Ping
State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Huan Jing Ke Xue. 2019 Nov 8;40(11):4987-4995. doi: 10.13227/j.hjkx.201903143.
To study the potential application characteristics of biochar as a phosphate adsorbent, nano-MgO-biochar was prepared by rapid pyrolysis of a mixture of MgO and lotus shells. The physicochemical properties were characterized by XRD, BET, SEM, and TEM, and adsorption experiments were conducted. The results showed that MgO was mainly supported on the surface of carbon in the form of flakes and granules, which increased the adsorption active site, and the adsorption amount of MgO-biochar MBC3 was 14 times higher than that of biochar MBC1 without MgO. The adsorption capacity of MBC9, which was prepared by rapid pyrolysis under 10% CO atmosphere, was further increased 16 times higher than that of MBC1. The adsorption kinetics followed a pseudo-second-order model, which indicated the adsorption of phosphate on MgO-biochar was dominated by chemical adsorption. According to the Langmuir equation, the maximum adsorption capacity of MBC3 and MBC9 could reach 283.26 mg·g and 297.96 mg·g, respectively. MgO-biochar is a high-efficiency phosphate adsorbent, which can be used to control the eutrophication of water.
为研究生物炭作为磷酸盐吸附剂的潜在应用特性，通过对氧化镁和莲子壳混合物进行快速热解制备了纳米氧化镁-生物炭。采用X射线衍射（XRD）、比表面积分析仪（BET）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对其理化性质进行表征，并开展吸附实验。结果表明，氧化镁主要以片状和颗粒状形式负载在碳表面，增加了吸附活性位点，氧化镁-生物炭MBC3的吸附量比不含氧化镁的生物炭MBC1高14倍。在10%CO气氛下通过快速热解制备的MBC9的吸附容量比MBC1进一步提高了16倍。吸附动力学遵循准二级模型，表明磷酸盐在氧化镁-生物炭上的吸附以化学吸附为主。根据朗缪尔方程，MBC3和MBC9的最大吸附容量分别可达283.26 mg·g和297.96 mg·g。氧化镁-生物炭是一种高效的磷酸盐吸附剂，可用于控制水体富营养化。
