生物炭负载纳米氯磷灰石复合材料对U(Ⅵ)的吸附性能及机理  

Adsorption properties and mechanism of biochar-supported nano-chloroapatite for U(Ⅵ)

作　　者：史妮静 谢水波 张澜涛[1] 姜培烜 麦颖清 胡恋 SHI Nijing;XIE Shuibo;ZHANG Lantao;JIANG Peixuan;MAI Yingqing;HU Lian(School of Civil Engineering,University of South China,Hengyang 421001,Hunan,China;Hunan Provincial Key Laboratory of Pollution Control and Resource Reuse Technology,University of South China,Hengyang 421001,Hunan,China;Hunan Agricultural and Forestry Industry Survey,Design and Research Institute,Changsha 410007,Hunan,China)

机构地区：[1]南华大学土木工程学院,湖南衡阳421001 [2]南华大学污染控制与资源化技术湖南省重点实验室,湖南衡阳421001 [3]湖南省农林工业勘察设计研究总院,湖南长沙410007

出　　处：《精细化工》2025年第1期176-185,共10页Fine Chemicals

基　　金：湖南省自然科学基金项目(2021JJ30579);湖南省研究生科研项目(CX20230972)。

摘　　要：将玉米芯负载纳米氯磷灰石(nClAP),后经高温(500℃)限氧制备了复合吸附材料(BC/nClAP),将其用于对水体中U(Ⅵ)的吸附。采用XRD、FTIR、XPS对BC/nClAP进行了表征。在初始铀质量浓度为5 mg/L下,考察了pH、BC/nClAP投加量、吸附时间、腐植酸(HA)对BC/nClAP吸附U(Ⅵ)性能的影响,探讨了BC/nClAP对U(Ⅵ)的吸附机理。结果表明,BC/nClAP投加量为0.10 g/L、pH=4.0、吸附时间120 min的最佳条件下,BC/nClAP对U(Ⅵ)的去除率高达99.7%;质量浓度>5 mg/L的HA显著影响BC/nClAP对U(Ⅵ)的吸附效果,并可将吸附平衡时间从60 min缩短至15 min以内;无论HA是否存在,BC/nClAP对U(Ⅵ)的吸附过程均符合准二级动力学方程和Langmuir等温吸附模型,表明此吸附过程是单分子层化学吸附;BC/nClAP对U(Ⅵ)吸附机理主要包括溶解-沉淀及生物炭表面含氧官能团的络合作用,BC/nClAP表面的活性官能团参与了络合反应,其中磷酸基团起到关键作用;HA会抢占BC/nClAP上的吸附位点,并与U(Ⅵ)形成游离在水中的U-HA复合物,从而改变了U(Ⅵ)和BC/nClAP表面的相互作用。Nanochloroapatite(nClAP)was loaded with corn cob to prepare composite adsorption materials(BC/nClAP)by high temperature(500℃)oxygen limiting,and used for aqueous U(Ⅵ)removal.BC/nClAP was characterized by XRD,FTIR and XPS.Under the initial uranium mass concentration of 5 mg/L,the effects of pH,dosage of BC/nClAP,adsorption time and humic acid(HA)on the U(Ⅵ)adsorption performance of BC/nClAP were analyzed,while the adsorption mechanism was also discussed.The results showed that under the optimal conditions of BC/nClAP dosage 0.10 g/L,pH=4.0 and adsorption time 120 min,the removal rate of U(Ⅵ)by BC/nClAP was up to 99.7%,and the adsorption capacity was 49.45 mg/g.HA with mass concentration>5 mg/L could shorten the adsorption equilibrium time from 60 min to less than 15 min,exhibiting significant influence on the U(Ⅵ)adsorption performance of BC/nClAP.Regardless of the presence or absence of HA,the adsorption process of U(Ⅵ)by BC/nClAP conformed to the quasi-second-order kinetic equation and the Langmuir isothermal adsorption model,indicating that the adsorption process was monomolecular layer chemisorption.The removal mechanism was mainly attributed to dissolution-precipitation and complexation of oxygen-containing functional groups on the surface of biochar,with phosphoric acid group played a key role.HA preempted the adsorption sites on BC/nClAP and formed free-in-water U-HA complex with U(Ⅵ),thus changing the surface interaction between U(Ⅵ)and BC/nClAP.

关 键 词：U(Ⅵ) 生物炭 氯磷灰石 生物炭负载纳米氯磷灰石 腐植酸 水处理技术 

分 类 号：X703[环境科学与工程—环境工程] TQ424[化学工程]