Title

Evaluation of the Inhibiting Effect of Graphene Oxide on Lead Leaching from Waste Cathode-Ray Tube Glass Incorporated in Cement Mortar

Abstract

A huge volume of waste cathode-ray tube (CRT) glass (containing a large content of PbO) is generated annually. In this study, evaluation of lead leaching in waste CRT glass within cement-based materials is addressed, and the role of graphene oxide (GO) in inhibiting lead leaching is studied. Lead leaching was evaluated using the toxicity characteristic leaching procedure (TCLP) and electrochemical impedance spectroscopy (EIS), and the microstructure was also characterized with scanning electron microscopy (SEM). The TCLP results indicated that Pb leaching of waste CRT mortar with GO addition was significantly controlled below the regulatory limit (5 mg/L) specified by United States Environmental Protection Agency (USEPA) and the Chinese Standard. A novel circuit model R0(Q1W(Q2R1)(Q3R22)) was successfully applied to evaluate the transport of lead in GO-waste CRT mortar by using EIS. The electrochemical parameters revealed that the microstructure of the bulk cover and waste CRT-mortar interface was improved by adding GO, indicating that lead transfer within the bulk cover and waste CRT-mortar interface was inhibited. Better attachment between waste CRT glass/bulk paste and higher density hardened structure with 0.1 wt% GO were observed in SEM images, indicating that the hardened structure can effectively encapsulate lead ions out of waste CRT glass in the interface and bulk paste.

Department(s)

Civil, Architectural and Environmental Engineering

Comments

The authors gratefully acknowledge the financial support provided by the National Natural Science Foundation of China of China (No. 51778368 , No. 51578341 ).

Keywords and Phrases

Cement; Electrochemical impedance spectroscopy; Graphene oxide; Lead leaching; Waste cathode ray tube (CRT) glass

International Standard Serial Number (ISSN)

0958-9465

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2019 Elsevier Ltd, All rights reserved.

Publication Date

01 Nov 2019

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