Zhu Ling, Zhao Nan, Tong Lihong, Lv Yizhong
College of Resources and Environmental Sciences, China Agricultural University Beijing 100193 China
Guangdong Provincial Key Lab of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University Guangzhou 510275 China.
RSC Adv. 2018 Jun 7;8(37):21012-21019. doi: 10.1039/c8ra03335h. eCollection 2018 Jun 5.
Potassium carbonate activated biochar (450 °C, 600 °C and 750 °C) and nonactivated biochar (600 °C) were prepared by using corn stalk as the raw material. These biochar samples were labeled as KBC450, KBC600, KBC750 and BC600. The physical and chemical properties of the biochar were strongly influenced by the activation of potassium carbonate. After activation with potassium carbonate, the aromatic, hydrophobic and non-polar properties of the biochar were enhanced to form an aromatized non-polar surface, and the aromatic properties were enhanced with the increase of the pyrolysis temperature. The outside surface of the activated biochar was similar to that of porous sponge with a mesoporous-microporous composite structure inside. The specific surface area of KBC600 was 5 times that of BC600, and KBC750 had a maximum surface area of 815 m g. Batch adsorption experiments showed that the adsorption capacity of KBC for naphthalene increased with the increase of pyrolysis temperature. The adsorption capacity of the biochar for naphthalene showed a significant positive correlation with O/C and (O + N)/C. KBC750 with the strongest surface hydrophobicity and the largest specific surface area had the largest adsorption capacity of 130.7 mg g. Physical adsorption and π-π EDA were the main adsorption mechanisms.
以玉米秸秆为原料制备了碳酸钾活化生物炭（450℃、600℃和750℃）和未活化生物炭（600℃）。这些生物炭样品分别标记为KBC450、KBC600、KBC750和BC600。碳酸钾活化对生物炭的物理化学性质有很大影响。经碳酸钾活化后，生物炭的芳香性、疏水性和非极性性质增强，形成芳构化的非极性表面，且芳香性随热解温度的升高而增强。活化生物炭的外表面类似于内部具有介孔 - 微孔复合结构的多孔海绵。KBC600的比表面积是BC600的5倍，KBC750的最大表面积为815 m²/g。批次吸附实验表明，KBC对萘的吸附容量随热解温度的升高而增加。生物炭对萘的吸附容量与O/C和（O + N）/C呈显著正相关。表面疏水性最强且比表面积最大的KBC750的最大吸附容量为130.7 mg/g。物理吸附和π-π电子供体-受体作用是主要的吸附机制。
