高孔隙率生物炭研制及其处理废水中磷酸盐

High porosity biochar and its treatment of phosphate in wastewater

生物炭是缺氧状态下生物质热解的产物;然而,常见的生物炭表面积小、孔隙结构不发达、表面活性基团少,吸附效果差。本文以高粱(GC)和柚子皮(YC)为原料,利用4种物质进行表面处理制备得到生物炭,其中制备的高粱/KOH(GC-KH)和柚子皮/KOH(YC-K)粉末表面孔状明显,证实了该工艺的可行性。GCKH比表面积为2096.05 m^(2)/g,平均孔径4.12 nm,在其表面含有丰富的含氧官能团,为吸附提供了良好的结构空间和活性位点。通过批量实验,探讨了不同因素对磷酸盐吸附的影响,评估了离子强度。等温线结果表明GC-KH对磷酸盐的吸附发生在单分子层表面,在p H值为7时GC-KH对磷酸盐最大吸附能力为74.73 mg/g,具有反应迅速等显著优势,为废水中磷酸盐的高效去除提供了创新路径。

Biochar is a product of pyrolysis of biomass under anoxic conditions;however,common biochar has a small surface area,underdeveloped pore structure,few surface active groups,and poor adsorption effect.In this work,biochar was prepared from sorghum(GC)and grapefruit peel(YC)by surface treatment using four substances to obtain biochar,where the prepared sorghum/KOH(GC-KH)and grapefruit peel/KOH(YC-K)powders had obvious surface porosity,confirming the feasibility of the process.With a specific surface area of 2096.05 m^(2)/g and an average pore size of 4.12 nm,GC-KH is rich in oxygen-containing functional groups on its surface,providing a good structural space and active sites for adsorption.The effect of different factors on phosphate adsorption was explored by batch experiments to assess the ionic strength.Results of isotherms showed that the adsorption of phosphate by GC-KH occurred on the surface of the monomolecular layer,and the maximum adsorption capacity of phosphate by GC-KH was 74.73 mg/g at pH=7.It has significant advantages such as rapid response,which provides an innovative pathway for the efficient removal of phosphate from wastewater.