生物质炭是指原料在部分缺氧或绝氧的条件通过特殊方法处理后产生的高度芳香化、高碳和高稳定性的固体产物。同一植物不同部位制备的生物质炭的性能往往具有较大差异, 本论文以胡麻为研究对象, 以KOH、H3PO4为活化剂, 对胡麻不同部位(杆、皮、根)进行活化, 采用水热炭化法、活化法、炭化-活化法制备生物质炭材料, 将产物用于吸附溶液中的罗丹明B(RhB)和亚甲基蓝(MB), 进一步评价其吸附活性。利用XRD、SEM、TG-DSC、N2-BET、UV-Vis等对产物的性能进行分析, 探究炭化温度、活化温度以及活化剂种类对生物质炭性能的影响。比较不同条件下制备生物质炭材料的微观形貌、比表面积、孔径以及产率。以胡麻杆为原材料, 磷酸为活化剂, 炭化温度200 ℃, 活化温度820 ℃时, 制备的生物质炭孔径分布均匀、数量较多、断面呈管状, 且其表面积最高, 可达1 247.63 m2/g。该产物对RhB和MB都表现出了良好的吸附能力, 在接近1 h时, 10 mg/L的RhB溶液就已经全部褪色, 吸附率高达100%。

Biochar is a solid product with high aromatization, high carbon and high stability produced by special treatment of raw materials under partial hypoxia or complete deoxygenation. Because the performance of biochar was prepared from different parts of the same plant often different, in this paper, hemp was taken as the research target, KOH and H3PO4 were used as activators, to activate the different parts (stem, skin and root) of hemp. Biochar materials from different sources were prepared by hydrothermal carbonization method, activation method and carbonization-activation method. The as-prepared products were used to adsorb rhodamine B (RhB) and methylene blue (MB) solutions, and their adsorption activities were evaluated. XRD, SEM, TG-DSC, N2-BET, UV-Vis and other characterization methods were used to analyze the properties of the products in order to explore the effects of carbonization temperature, activation temperature and activator type on the properties of biochar. Using flax rod as raw material, phosphoric acid as activator, carbonization temperature 200 ℃, activation temperature 820 ℃, the biochar pores were prepared with uniform distribution, a large number of cross sections in tubular shape. The specific surface area of the biochar is as high as 1 247.63 m2/g. It is also displayed great adsorption capacity for RhB and MB. After nearly 1 h, the 10 mg/L RhB solution has all faded, and the adsorption rate is as high as 100%.