预处理对泥炭孔结构的影响

Effects of Pretreatment on Pore Structure of Peat

以草本泥炭为原料,进行酸、碱、超声波和微波预处理,然后生物发酵产生甲烷,对预处理及生物发酵产生甲烷前后的泥炭进行N_(2)-吸附孔结构测定和SEM测定。结果表明:碱预处理泥炭甲烷产气量最高为44.73 mL/g(原料挥发性固体质量),与未预处理组相比增加200.20%;碱、酸、超声波和微波预处理后泥炭的比表面积和总孔容增加,平均孔径减小,其中碱预处理泥炭比表面积达4.43 m^(2)/g,总孔容为0.0162 m^(3)/g,平均孔径为14.64 nm;预处理泥炭生物发酵产生甲烷后,比表面积和总孔容减小,平均孔径增大,其中,碱预处理泥炭比表面积降为2.02 m^(2)/g,总孔容减小为0.0123 m^(3)/g,平均孔径增加至24.20 nm;酸、碱、超声波和微波预处理会对泥炭物理结构中的孔结构产生影响,提高甲烷产量,促进泥炭生物甲烷转化。

Using herbaceous peat as raw material,the biomethane fermentation was carried out after the acid,alkali,ultrasonic and microwave pretreatments.The pore structure of the peat before and after pretreatments and the biomethane fermentation were obtained via the N_(2)-adsorption and SEM characterization methods.The results show that the highest methane production of the alkali-pretreated peat is 44.73 mL/g(volatile solid mass of raw material),which is 200.20%higher than that of the unpretreated peat.The specific surface area and pore volume of the peat increase after pretreatments,while the average pore diameter decreases.The specific surface area of the alkali-pretreated peat is 4.43 m^(2)/g,and the pore volume is 0.0162 m^(3)/g with the average pore diameter corresponding to 14.64 nm.After the biomethane fermentation,the specific surface area and pore volume of the pretreated peat decrease,while the average pore diameter increases.The specific surface area and pore volume of the alkali-pretreated peat decrease to 2.02 m^(2)/g and 0.0123 m^(3)/g,respectively,and the average pore diameter increases to 24.20 nm.The results show that the acid,alkali,ultrasonic and microwave pretreatments can affect the pore structure of the peat,increasing the methane production and promoting the conversion of the peat biomethane.