Use of nanoscale zero-valent iron for remediation of clayey soil contaminated with hexavalent chromium : batch and column tests

This study investigated the reduction of hexavalent chromium (Cr(VI)) in a clayey residual soil using nanoscale zero-valent iron (nZVI). Five di erent ratios between nZVI and Cr(VI) were tested in batch tests (1000/11; 1000/23; 1000/35; 1000/70, and 1000/140 mg/mg) with the soil. With the selected p...

ver descrição completa

Detalhes bibliográficos
Autores: Reginatto, Cleomar, Cecchin, Iziquiel, Heineck, Karla Salvagni, Thome, Antonio, Reddy, Krishna R.
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2020
País:Brasil
Recursos:Universidade Federal do Rio Grande do Sul (UFRGS)
Repositório:Repositório Institucional da UFRGS
Idioma:inglês
OAI Identifier:oai:www.lume.ufrgs.br:10183/210476
Acesso em linha:http://hdl.handle.net/10183/210476
Access Level:Acceso aberto
Palavra-chave:Contaminação do solo
Remediação ambiental
Nanopartículas de ferro
Soil remediation
Nanotechnology
Nanoscale zero-valent iron-(nZVI)
Hexavalent chromium-Cr(VI)
Descrição
Resumo:This study investigated the reduction of hexavalent chromium (Cr(VI)) in a clayey residual soil using nanoscale zero-valent iron (nZVI). Five di erent ratios between nZVI and Cr(VI) were tested in batch tests (1000/11; 1000/23; 1000/35; 1000/70, and 1000/140 mg/mg) with the soil. With the selected proportion resulting best e ciency, the column tests were conducted, with molded specimens of 5 cm in diameter and 5 cm in height, with di erent nZVI injection pressures (10, 30, and 100 kPa). The soil was contaminated with 800 mg/kg of Cr(VI). The Cr(VI) and Cr(III) analyses were performed following the USEPA 3060A and USEPA 7196A standards. The results show that the reduction of Cr(VI) is dependent on the ratio between nZVI and Cr(VI), reaching 98% of e ciency. In column tests, the pressure of 30 kPa was the most e cient. As pressure increased, contaminant leaching increased. The permeability decreased over time due to the gradual increase in filtration and formation of oxyhydroxides, limiting nZVI mobility. Overall, nZVI is e cient for soil remediation with Cr(VI), but the injection process can spread the contaminated if not properly controlled during in situ application.

Registros relacionados