Adsorption of cadmium using modified zeolite-supported nanoscale zero-valent iron composites as a reactive material for PRBs

Saeideh Tasharrofi; Zahra Rouzitalab; Davood Mohammady Maklavany; Ali Esmaeili; Mohammadmehdi Rabieezadeh; Mojtaba Askarieh; Alimorad Rashidi; Hossein Taghdisian

doi:10.1016/j.scitotenv.2020.139570

Adsorption of cadmium using modified zeolite-supported nanoscale zero-valent iron composites as a reactive material for PRBs

Sci Total Environ. 2020 Sep 20:736:139570. doi: 10.1016/j.scitotenv.2020.139570. Epub 2020 May 21.

Authors

Saeideh Tasharrofi¹, Zahra Rouzitalab², Davood Mohammady Maklavany³, Ali Esmaeili¹, Mohammadmehdi Rabieezadeh¹, Mojtaba Askarieh³, Alimorad Rashidi⁴, Hossein Taghdisian¹

Affiliations

¹ Environment and Biotechnology Research Division, RIPI, Tehran, P.O. Box 14857-33111, Tehran, Iran.
² Civil Engineering Division, College of Environment, Karaj, P.O. Box 31746-74761, Alborz, Iran.
³ Carbon and Nanotechnology Research Center, RIPI, Tehran, P.O. Box 14857-33111, Tehran, Iran.
⁴ Carbon and Nanotechnology Research Center, RIPI, Tehran, P.O. Box 14857-33111, Tehran, Iran. Electronic address: rashidiam@ripi.ir.

PMID: 32485377
DOI: 10.1016/j.scitotenv.2020.139570

Abstract

The main challenge in utilizing permeable reactive barriers (PRB) for remediation of metals-contaminated groundwater is determination of a proper low-cost reactive medium that can remove the desired contaminants simultaneously. In this study, the performance of different zeolite materials and nZVI-based adsorbents for cadmium (Cd) removal was compared. Further, a composite of the best nZVI and zeolite samples was synthesized with the removal efficiency of 20.6 g/kg and selected as the proposed adsorbent. Moreover, the characteristics of the composite were analyzed through different techniques (BET, XRF, XRD, FT-IR, FE-SEM and EDX). In addition, through kinetic and thermodynamic studies, the effect of temperature, pH, ionic strength and presence of other metal ions on Cd removal efficiency was investigated. According to the results, since sodium zeolite (NaZ) provides a large number of specific ion-exchange sites for decoration with nZVI, stabilizes nZVI, and prevents its aggregation and further leaching in the harsh environment, the NaZ-nZVI composite is capable of removing Cd by adsorption and is applicable in PRBs, and thus it seems that the aforementioned composite is a proper candidate for groundwater remediation from a wide range of metal ions.

Keywords: Cadmium; Groundwater; In-situ remediation; Permeable reactive barriers; Zeolite; nZVI.