Point of Zero Charge: Role in Pyromorphite Formation and Bioaccessibility of Lead and Arsenic in Phosphate-Amended Soils

摘要: Soluble lead (Pb) can be immobilized in pure systems as pyromorphite through the addition of phosphorus (P) sources; however, uncertainties remain natural systems. Knowledge point zero charge (PZC) is important to predict ionization functional groups and their interaction with metal species solution. This study utilized Pb- As-contaminated soils determine combined effect pH respect PZC different rates P-application on formation well Pb arsenic (As) bioaccessibility impacted by speciation changes. Solution chemistry analysis along synchrotron-based As-speciation treatment ratios (TERs) were conducted. Results indicated no significant P-amended soils; TERPb appeared significantly lower at > pHPZC higher compared other two treatments for tested soils. The lack conversion soil may attributed several reasons including presence highly stable minerals, such plumbojarosite, limiting soluble availability react phosphates, high Fe S content IKS, organic matter BO, Ca NW.