改性生物质炭在沼液净化中的应用研究

The Effects of Modified Biochar on the Purificaiton of Biogas Slurry

摘要: 本研究以竹屑、松木两种不同的农林废弃物为原料制备生物质炭，并利用酸、碱、氧化、超声及氯化铁等改性方法对生物质炭进行改性，以比对研究各种不同生物质炭对沼液的净化能力。同时，采用元素分析、扫描电镜和傅立叶红外光谱等分析方法对不同改性生物质炭进行表征。结果表明：竹屑生物质炭的芳香性优于松木生物质炭，改性后的生物质炭不仅表面更加粗糙，而且改变了官能团的簇度以及红外吸收峰的强度。通过对模拟沼液进行静态吸附实验，对比分析各改性生物质炭对沼液中氨氮、总磷和化学需氧量的吸附效果及其机理。结合等温吸附实验研究其吸附性能，等温吸附实验结果表明各生物质炭对氨氮、总磷、COD均符合Langmuir等温吸附方程，且净化效果均比未改性炭有不同程度的提高。

Abstract: In this study, two raw materials namely bamboo bits and pine sawdust were employed to manu-facture biochar, followed by different modifications in terms of acidification, alkalization, oxidation, ultrasonic and ferric chloride, in an attempt to compare the purification capacity of these biochars. Meanwhile, such advanced analytical techniques as elemental analysis, scanning electronic microscopy and Fourier infrared spectrometer were used to characterize the surface properties of these biochars. The results showed that aromaticity of bamboo biochar were higher than pine biochar. All modification processes led to a coarser surface and changed the cluster density of functional group thereon as well as the relevant peak areas of infrared absorption. The adsorption capacity of the unmodified or modified biochar toward the ammonia-N, total P and COD were testi-fied via bench adsorption experiment of biogas slurry, in combination with the isothermal adsorp-tion tests. The outcomes showed that the modification of biochar could significantly improve their maximum capacity of biochar to the ammonia-N, total P and COD and their isothermal adsorptions were well fitted by Langmuir equation.