硫酸改性小麦秸秆生物炭对氨氮吸附特性研究

Adsorption characteristics of ammonium nitrogen in aqueous solution for biochar modified with sulfuric acid

以小麦秸秆制备生物炭(550℃)、并以硫酸作为改性剂制备得到改性生物炭材料,通过SEM、BET、元素分析、FTIR、Boehm滴定等材料学方法,发现改性后,表面出现显著的规则孔穴结构,孔径分布在0.6~1.0 nm出现集聚;比表面积较未改性组增加54%,达189.2 m^2/g;酚羟基类酸性官能团增加522%,达0.56 mmol/g。吸附性能实验显示,经济改性条件是70%硫酸反应24 h;等温吸附曲线更符合Langmuir模型,吸附量增加69%,达19.12 mg/L,吸附能力显著提高。

Biochar prepared using wheat straw（ 550 ℃） and modified by sulfuric acid,which are examined by the techniques of SEM,BET,elemental analysis,FTIR,Boehm titration,etc.,reveals significant and regular pore structure with size distribution in the aggregation range of 0. 6 ~ 1. 0 nm. The surface area of RAW（ unmodified biochar） increased 54% to 189. 2 m^2/g for modified biochar samples. The amount of phenolic hydroxyl increased 522% to 0. 56 mmol/g. Process optimization shows 70% sulfuric acid with24 h reaction time is relatively economical. The adsorption process is better fit for Langmuir model. The adsorption amount increased 69% to 19. 12 mg/L revealing significant increase on the adsorption ability.