农业环境科学学报Issue(9)：1817-1822,6.DOI:10.11654/jaes.2014.09.020
铁改性生物炭对磷的吸附及磷形态的变化特征
Phosphorus Adsorption by and Forms in Fe-modified Biochar
摘要
Abstract
Biochar has great potential to adsorb phosphorus, and its phosphorus forms are important for phosphorus release and bioavailabili-ty. In this study, wheat straw derived biochar was used to examine the changes of elements and surface functional groups, phosphorus ad-sorption and forms in biochar after modification. Modification obviously decreased C mass fraction, but increased O and Fe mass fractions in the biochar. The content of carboxyl in biochar significantly increased, while basic functional groups decreased after modification. Modifica-tion led to the equilibrium time of phosphorus adsorption by biochar increasing from 60 min to 120 min. The maximum adsorption capacity of phosphorus by Fe-modified biochar was 10.1 mg·g-1, which was 19.4 times that of unmodified biochar. The content of exchangeable phos-phorus in unmodified biochar accounted for 82.1% of the total adsorption, suggesting that the adsorption mechanism was mainly physical adsorption. However, the content of iron-bound phosphorus in Fe-modified biochar was 66.7%of the total adsorption, while exchangeable phosphorus only 26.6%, implying that phosphorus was adsorbed by chemical adsorption. Increasing initial pH enhanced the removal per-centage of phosphorus by Fe-modified biochar until pH7, and then decreased. The pH dependence of phosphorus removal rates was closely related to the content of exchangeable phosphorus. Increased pH might promote iron-bound phosphorus transform into occluded phosphorus.关键词
铁改性生物炭/吸附/磷形态/pHKey words
Fe-modified biochar/adsorption/phosphorus forms/pH分类
资源环境引用本文复制引用
蒋旭涛,迟杰..铁改性生物炭对磷的吸附及磷形态的变化特征[J].农业环境科学学报,2014,(9):1817-1822,6.基金项目
国家重大水专项 （）
