镁铁改性水葫芦炭去除水体氮磷的效能与作用机理  

Efficacy and mechanisms of nitrogen and phosphorus removal from water bodies by magnesium-iron modified water hyacinth biochar

作　　者：庄海峰 张靖婕 陈青昀 李嘉琦 林洲洋 傅建舟 ZHUANG Haifeng;ZHANG Jingjie;CHEN Qingyun;LI Jiaqi;LIN Zhouyang;Fu Jianzhou(School of Environmental and Natural Resources,Zhejiang University of Science&Technology,Hangzhou 310023,China;Zhoushan Agricultural Science Research Institute,Zhoushan 316004,China)

机构地区：[1]浙江科技大学环境与资源学院,杭州310023 [2]舟山市农业科学研究院,舟山316004

出　　处：《环境工程学报》2024年第12期3493-3506,共14页Chinese Journal of Environmental Engineering

基　　金：国家重点研发计划资助项目(2022YFE0196000)。

摘　　要：农业种养过程产生大量氮磷流失,严重加剧水体富营养化程度。为缓解氮磷污染对水环境和人类健康的危害,本研究使用可修复水体中重金属的废弃物水葫芦作为原料,经热解炭化、水热负载优化制备高吸附容量的镁铁改性水葫芦炭(KBC@Mg-Fe),通过批量实验考察了投加量、pH、氮磷初始质量浓度、共存离子等因素对吸附性能的影响。结果表明,KBC@Mg-Fe对氮磷的吸附能力远高于原始炭,镁铁改性使水葫芦生物炭的比表面积提高了70.41%,孔体积和孔径均明显增加,并在改性后表面有效附着镁铁氧化物。随着KBC@Mg-Fe投加量的增加,氮磷的去除率先增加后平衡,在pH=9~12内均有优异的氮磷吸附性能,废水中共存离子及有机物对氮磷去除的影响不明显。KBC@Mg-Fe通过鸟粪石沉淀、表面官能团作用、静电吸引及离子交换去除水中氮磷,符合拟二级吸附动力学模型和Langmuir吸附等温模型,表明该吸附以单层化学吸附为主,最大吸附量分别为124.07和160.51 mg·g^(−1),具有良好的吸附性能,因此,以上研究结果表明,KBC@Mg-Fe可显著提高氮磷的吸附能力,可实现水体修复后废弃水葫芦的资源化利用。The substantial loss of nitrogen and phosphorus during agricultural activities,such as fertilization and the cultivation of livestock,poultry,and aquaculture,has led to an exacerbation of severe eutrophication of water bodies.To mitigate the risks to environmental and health posed by nitrogen and phosphorus,the water hyacinth waste was used as raw material to remediate heavy metals in water bodies,a type of magnesium-ironmodified water hyacinth biochar(KBC@Mg-Fe)with high adsorption capacity was prepared through pyrolysis carbonization and hydrothermal load optimization.The effects of dosage,pH,initial mass concentration of nitrogen and phosphorus,and co-existing ions on the adsorption performance were investigated through batch experiments.The results indicate that KBC@Mg-Fe had a significantly higher adsorption capacity for nitrogen and phosphorus than the original biochar.The modification with magnesium and iron increased the surface area of the water hyacinth biochar by 70.41%,the pore volume and diameter,and magnesium and iron oxides were effectively attached on the modified surface.With the increase of KBC@Mg-Fe dosage,the removal of nitrogen and phosphorus firstly increased and then approached to equilibrium,and an excellent adsorption performance occurred within the pH range of 9 to 12.Co-existing ions and organic matter in wastewater had negligible effects on nitrogen and phosphorus removal.The nitrogen and phosphorus removal by KBC@Mg-Fe was achieved through struvite precipitation,interaction with surface functional groups,electrostatic attraction,and ion exchange,which was well fitted with the pseudo-second-order kinetic model and Langmuir adsorption isotherm,indicating that the adsorption was dominated by a monolayer chemical adsorption,and the maximum adsorption capacities were 124.07 mg·g^(−1) and 160.51 mg·g^(−1),respectively,demonstrating a good adsorption performance for [e-mail],the above research results indicate that KBC@Mg-Fe can significantly enhance nitrogen and phosphorus

关 键 词：水葫芦生物炭 铁镁共改性 氮磷共吸附 机理 

分 类 号：X703[环境科学与工程—环境工程]