钙矾石对Pb(Ⅱ)的化学俘获  

Chemical Entrapment of Pb(Ⅱ) by Ettringite

作　　者：蓝俊康[1] 丁凯[1] 吴孟[1] 刘宝剑[1] 

机构地区：[1]桂林理工大学环境科学与工程学院,广西桂林541004

出　　处：《桂林工学院学报》2009年第4期531-534,共4页Journal of Guilin University of Technology

基　　金：广西环境工程与保护评价重点试验室研究基金项目(桂科能0701K009);广西高校人才小高地建设"环境工程"创新团队资助计划项目(桂教人[2007]71)

摘　　要：为查明钙矾石对Pb(Ⅱ)能否产生化学俘获以及发生俘获所需的必要条件,在室温下试用Pb(NO3)2与A l2(SO4)3、NaOH等进行人工液相合成Pb类钙矾石,即Pb6[A l(OH)6]2.3SO4.26H2O,并用CaO、Pb(NO3)2、A l2(SO4)3和蒸馏水等人工合成Ca-Pb钙矾石{(Ca,Pb)6[A l(OH)6]2.3SO4.26H2O}。试验表明:Pb6[A l(OH)6]2.3SO4.26H2O不能形成,但Ca-Pb钙矾石却能合成。这说明利用溶液反应法合成钙矾石时,若液相中缺Ca2+,则Pb(Ⅱ)不能被钙矾石所俘获,只有当液相中出现了Ca2+时,Pb(Ⅱ)才能被钙矾石所俘获。另外,所合成的Ca-Pb钙矾石与纯钙矾石相比,其X射线衍射图谱发生了明显的改变,表明钙矾石在俘获了Pb(Ⅱ)后其晶格发生了一些变异。掺Pb(Ⅱ)的水泥熟料净浆在水化龄期为7 d时,其XRD图谱也发生了一些变化,有Ca-Pb钙矾石存在的迹象。This work aims to make clear whether Pb（ Ⅱ ） can be chemically entrapped by ettringite and under what conditions this entrapment can take place. Al2 （SO4）3and NaOH react with Pb（ NO）3in synthetic liquid to produce the lead analog of ettringite, Pb6 [ Al （OH） 6 ] 2 · 3SO4 · 26H2O under room temperature. Furthermore, CaO, Pb （NO3 ）2, Al2 （SO4）3 and distilled water are used to synthesize Ca-Pb ettringite, （Ca, Pb）6 [ Al （OH）6 ] 2 ·3SO4· 26H2O. The results show that Pb6 [ Al （OH） 6 ] 2 · 3SO4 · 26H2O can＇ t form, while Ca - Pb ettringite can be produced. Pb （ Ⅱ ） can＇ t be entrapped by ettringite when calcium is absent during liquid phase reactions. However,Pb（ Ⅱ ） can be entrapped by ettringite when calcium is adequate in liquid phase. The X-ray diffraction peaks for Ca- Pb ettringite is significantly different from pure ettringite, indicating that ettringite lattice changes a little after accommodating lead. Experiments on Pb（ Ⅱ ）solidified by 100% cement clinker show that XRD patterns for 7-days storage period change after they doped with lead,indicating that some Pb（ Ⅱ ） has entered into ettringite lattice.

关 键 词：钙矾石 俘获 PB(II) 

分 类 号：X703[环境科学与工程—环境工程] X705