生物炭作为一种新兴的碳质吸附剂，具有良好的VOCs控制功能。以玉米芯为原料，制备了一系列生物炭(BCx)和碳酸钾活化生物炭(KBC-x-y) (其中，x为炭化温度，y为活化温度)用于吸附苯。利用热重分析、氮气吸附−脱附、扫描电镜(SEM)以及元素分析(EA)等方法获得了生物炭(质)样品的热解特性、比表面积、孔容孔径、表面形态及原子占比等，通过吸附实验考察炭化温度/活化温度对生物炭吸附苯的影响。结果表明：碳酸钾活化后的生物炭比表面积最高可达576.76 m²/g，孔容积为0.325 m³/g，对苯的最大吸附量达到82.51 mg/g(较未活化生物炭提升2.9倍)；炭化温度与吸附能力呈现正态分布的趋势，吸附能力随着炭化温度的升高而增强，但过高的炭化温度(> 800 ℃)会导致气孔堵塞、数量减少，比表面积降低，吸附能力下降；低温/高温炭化下，生物炭吸附能力随活化温度变化呈现出相同趋势；高温炭化后(800 ℃)，最佳活化温度为400 ℃(KBC-800-400)，活化温度太高会导致微孔孔壁破碎以及挥发物的烧结效应，从而降低吸附能力，较低的活化温度未能使K₂CO₃在炭表面充分反应；低温炭化后(400 ℃)，最佳活化温度为(800 ℃)，低温炭化高温活化生物炭(KBC-400-800)吸附性能优于高温炭化低温活化生物炭(KBC-800-400)，可能是因为在低温炭化情况下，较高的活化温度有利于碳酸钾参与活化过程反应。

As a new kind of carbonaceous adsorbent, biochar has a good function of controlling VOCs. A series of biochar (BCx) and potassium carbonate activated biochar (KBC-x-y) were pre-pared from corncob for benzene adsorption. Thermogravimetric analysis, nitrogen adsorption-desorption, scanning electron microscopy (SEM) and elemental analysis (EA) were used to char-acterize the pyrolytic properties, specific surface area, pore volume and pore size, surface mor-phology and atomic percentage of the biochar (mass) samples. The effects of carboniza-tion/activation temperature on benzene adsorption were investigated by adsorption experiments. The results show that the specific surface area of biochar modified by potassium carbonate is up to 576.76 m²/g, the pore volume is 0.325 m³/g, and the maximum adsorption capacity of benzene is up to 82.51 mg/g (2.9 times higher than that of unmodified biochar). The carbonization temperature and adsorption capacity show a trend of normal distribution. The adsorption capacity increases with the increase of carbonization temperature, but the high carbonization temperature above 800 ℃ will lead to the clogging of pores, decrease in number, decrease in specific surface area and decrease in adsorption capacity. The adsorption capacity of biochar shows the same trend with the activation temperature under low/high carbonization temperature. After high-temperature carbonization (800 ℃), the optimum activation temperature is 400 ℃ (KBC-800-400). If the activation temperature is too high, it will lead to the fracture of micropore wall and the sintering effect of volatiles, thus reducing the adsorption capacity. Lower activation temperature fails to make K₂CO₃ fully react on the carbon surface. After low-temperature carbonization (400 ℃), the optimal activation temperature is (800 ℃). The adsorption performance of low-temperature carbonized high-temperature activated biochar (KBC-400-800) is better than that of high-temperature carbonized low-temperature activated biochar (KBC-800-400). It is possibly because the higher activation temperature facilitates the involvement of potassium carbonate in the reaction of the activation process in the case of low temperature car-bonization.