改性污泥炭对典型重金属的吸附特性研究  

Study on adsorption characteristics of modified sludge charcoal for typical heavy metals

作　　者：叶金宇 李鑫隆 陈凤贤 洪舒晨 薛向东 YE Jinyu;LI Xinlong;CHEN Fengxian;HONG Shuchen;XUE Xiangdong(School of Civil Engineering and Architecture,Zhejiang University of Science and Technology,Hangzhou 310023,Zhejiang,China;Hangzhou Wodian Environmental Protection Technology Co.,Ltd.,Hangzhou 310053,Zhejiang,China)

机构地区：[1]浙江科技大学土木与建筑工程学院,杭州310023 [2]杭州沃点环保科技有限公司,杭州310053

出　　处：《浙江科技大学学报》2024年第6期538-548,共11页Journal of Zhejiang University of Science and Technology

基　　金：国家自然科学基金项目(42307479);嘉善科技计划项目(2023A43);浙江科技学院研究生教学改革项目(2021yjsjg01)。

摘　　要：【目的】污泥基生物炭(sludge-based biochar,SBC)可用于水体中重金属的去除。然而,不同改性方法制备的SBC在理化性质表征上差异较大,而它对重金属的吸附选择优先性及机理尚不明确。因此有必要探讨不同改性方法制备的SBC对典型重金属的吸附特性及机理。【方法】首先,以剩余污泥为原料,制备了Zn和N改性的水热污泥炭(hydrothermal biochar,HTC)和热解污泥炭(pyrolysis biochar,PSC),并对其表面形貌、孔隙分布和晶相特征进行了表征;然后,筛选出对重金属吸附效果较好的SBC,研究其吸附动力学及等温吸附特征;最后,通过电负性和官能团特征,探讨其对重金属的吸附选择优先性及机理。【结果】1)相较于烘干污泥(drying sludge,DS),HTC和PSC改性前后的比表面积和总孔容总体上有所增大,且与处理温度呈正相关;2)DS和PSC200(200℃水热法制备的PSC)、HTC200(200℃水热法制备的HTC)及N-PSC400(400℃N改性PSC)对典型重金属的吸附能力更强,其吸附特征符合准二级动力学和Langmuir等温吸附模型;3)DS和3种SBC对重金属的吸附选择性由大到小依次为Pb^(2+)、Cu^(2+)、Ni^(2+)、Cd^(2+);4)DS和3种SBC对Cd^(2+)、Pb^(2+)和Cu^(2+)吸附的主要官能团分别是—OH和N—H,而对Ni^(2+)吸附的主要官能团是—OH、N—H和C—N。【结论】本研究揭示了不同改性方法制备的HTC和PSC对典型重金属离子的吸附性能和机理差异,为其在水体中重金属污染治理中的应用提供了新见解。[Objective]Sludge based biochar(SBC)has the ability to remove heavy metals from water bodies.However,it is difficult to uniformly compare the physicochemical properties of SBC prepared by different modification methods,and its adsorption selectivity and mechanism for heavy metals are not yet clear.Therefore,it is necessary to explore the adsorption characteristics and mechanism of SBC prepared by different modification methods for typical heavy metals.[Method]Firstly,Zn and N modified hydrothermal biochar(HTC)and pyrolysis biochar(PSC)were prepared from residual sludge,with their surface morphology,pore distribution,and crystal phase characteristics being characterized;then,SBC good at adsorbing heavy metals was selected to study its adsorption kinetics and isotherm adsorption characteristics;finally,through electronegativity and functional group characteristics,the adsorption selectivity and mechanism for heavy metals were explored.[Result]1)Compared with drying sludge(DS),HTC,PSC,and their modified products show an increase in specific surface area and total pore volume,being positively correlated with treatment temperature;2)DS and PSC200(PSC prepared by hydrothermal method at 200℃),HTC200(HTC prepared by hydrothermal method at 200℃),and N-PSC400(PSC modified by N at 400℃)have stronger adsorption capacity for typical heavy metals,and their adsorption characteristics conform to quasi second order kinetics and Langmuir isotherm adsorption model;3)the adsorption selectivity of DS and three types of SBC for heavy metals is ranked from large to small as follows:Pb^(2+),Cu^(2+),Ni^(2+),Cd^(2+);4)the main functional groups for the adsorption of Cd^(2+),Pb^(2+),and Cu^(2+) by DS and three types of SBC are—OH and N—H,respectively,while the main functional groups for the adsorption of Ni^(2+) are—OH,N—H,and C—N.[Conclusion]This study reveals the differences in adsorption performance and mechanism of HTC and PSC prepared by different modification methods for typical heavy metal ions,providing new insights

关 键 词：污泥炭 改性 吸附 重金属 

分 类 号：X703[环境科学与工程—环境工程]