Ultrahigh removal performance of lead from wastewater by tricalcium aluminate via precipitation combining flocculation with amorphous aluminum. (10th February 2020)

• Record Type: Journal Article
• Authors: Zhang, Ping; Ouyang, Sida; Li, Peng; Sun, Zhaoyi; Ding, Nengshui; Huang, Yun
• Is Part Of: Journal of cleaner production. Volume 246(2020)
• Publication Date: 2020-02-10
• Subjects: Tricalcium aluminate (C3A) -- Lead (Pb) -- Removal mechanism -- Precipitation -- Flocculation; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2019.118728
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Lead (Pb) removal is an urgent issue of industrial wastewater treatment due to its fatal harm on human health. In this study, for the first time, the efficient removal of Pb by cement-based material tricalcium aluminate (C3 A) have been reported. The ultrahigh removal capacity of 1747.1 mg·g −1 for Pb by C3 A was achieved at the dosage of 0.5 g·L −1 within 1 h. The removal behaviors investigated by batch experiments illustrated that the C3 A dosage and initial Pb concentration significantly influenced the removal behavior. And the removal process was identified to be a pH-independence process accompanying with a chemical reaction. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and the chemical precipitation thermodynamic model PHREEQC were employed to elucidate the removal mechanism. Amorphous aluminum released by C3 A hydration played a major role in Pb removal via flocculation at low Pb concentration (<600 mg·L −1 ), while the precipitation of lead and the flocculation of amorphous aluminum are the primary lead removal pathways at high Pb concentrations (>600 mg·L −1 ). C3 A could remove Pb to an acceptable level (WHO standard) from authentic wastewaters at low Pb concentration (∼20 mg·L −1 ), or remove ∼70% Pb from authentic wastewaters at high concentration (ca. 700 mg·L −1 ). This work presents C3 A as an excellent material for lead removal and broadens the potential application of cement-based materials in environmental remediation. Graphical abstract: Image 1 Highlights: Tricalcium aluminate (C3 A) was fabricated via solid state reaction for lead clean-up. Removal behavior was influenced by C3 A dosage and initial lead concentration. The maximum removal capacity was 1747.1 mg g −1 at the dosage of 0.5 g L −1 . The removal mechanism was revealed based on experiment and theories with PHREEQC. The mechanism was precipitation combining flocculation with amorphous aluminium.