Title: Fate and transport of arsenic-loaded zero-valent iron nanoparticles in subsurface systems

Irene M.C. Lo

Hong Kong University of Science and Technology, China


Prof. Irene M. C. Lo is currently a Chair Professor in the Department of Civil and Environmental Engineering and Director of Environmental Engineering and Management Program at The Hong Kong University of Science and Technology (HKUST). She has been joining HKUST since 1992. Prof. Lo is an elected Academician of the European Academy of Sciences and Arts (EASA). Prof. Lo was the recipient of the 2004 ASCE James Croes Medal, the 2007 ASCE Samuel Arnold Greeley Award, the 2008 EWRI Best Practice-Oriented Paper Award, the 2009 ASCE Wesley W Horner Award, and the 2012 ASCE EWRI Best Practice-Oriented Paper Award. Prof. Lo has held 3 Patents, edited 7 technical books, published over 270 SCI journal articles and conference papers with citation of 10700+ and H-index of 53, and given more than 30 plenary/keynote lectures at international conferences.


Nano zero-valent iron (nZVI) is widely used in the arsenic (As) remediation of groundwater. During the remediation, nZVI reacts with As and then forms As-loaded nZVI. Unfortunately, some concerns occur regarding the release of As-loaded nZVI particles and their subsequent transport in aquatic environments, as well as the As release from As-loaded nZVI. This study investigated the fate and transport of the three types of As-loaded nZVI (As-loaded pristine, chitosan-modified and polyaniline-modified nZVI) at two levels of As loadings (low and high) by column studies.
From the column results, we found that surface modification and high As loading enhanced the mobility of the three types of As-loaded nZVI. The As in the effluent was from the As release when nZVI was not detected. It was evident that the mobility of the three types of As-loaded nZVI particles were limited, at both As loadings. Thus, the As release, instead of As-loaded nZVI particles, can cause wide As contamination in groundwater.
This study is the first time to systematically investigate the fate and transport of As-loaded nZVI in groundwater system. The findings could assess the potential risk caused by the As released from the As-loaded nZVI under different geochemical conditions and also provide guidelines for the selections of surface modification as well as the nZVI dosage regarding the As release in groundwater. 

Audience take away:
• The presentation is suitable for those delegates who are using nanomaterials for environmental applications
• The presentation will cover the material synthesis, application, the concerns of using nanomaterials, and practical issues using nanomaterials