CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > Environmental Chemistry   
Environmental Chemistry
Journal Banner
  Environmental problems - Chemical approaches
 
blank image Search
 
blank image blank image
blank image
 
  Advanced Search
   

Journal Home
About the Journal
Editorial Boards
Contacts
Content
Online Early
Current Issue
Just Accepted
All Issues
Virtual Issues
Special Issues
Research Fronts
Sample Issue
Call for Papers
For Authors
General Information
Notice to Authors
Submit Article
Open Access
For Referees
Referee Guidelines
Review an Article
For Subscribers
Subscription Prices
Customer Service

blue arrow e-Alerts
blank image
Subscribe to our Email Alert or RSS feeds for the latest journal papers.

red arrow Connect with us
blank image
facebook twitter youtube

 

 Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.


Factors affecting arsenic and uranium removal with zero-valent iron: Laboratory tests with Kanchanâ„¢-type iron nail filter columns with different groundwaters

Christine Wenk, Ralf Kaegi, Stephan Hug

Abstract

Zero-valent Iron (ZVI) based filters are able to remove arsenic and other pollutants from drinking water, but their performance depends on the form of ZVI, filter design, water composition and operating conditions. Kanchan™ filters use an upper bucket with ZVI in the form of commercial iron nails, followed by a sand filter, to remove arsenic and pathogens. We evaluated factors that influence the removal of arsenic and uranium with laboratory columns containing iron nails with six different synthetic groundwaters with 500 ug/L As(III), 50 ug/L U, 2 mg/L B, and with 0 and 2 mg/L P (o-phosphate), 0.25 and 2.5 mM Ca, 3.2 and 8.3 mM HCO3-, pH 7.0 and pH 8.4 over 30 days. During the first ten days, As-removal was 65-95% and strongly depended on the water composition. As-removal at pH 7.0 was better than at pH 8.4 and high P combined with low Ca decreased As-removal. From 10-30 days, As-removal decreased to 45-60% with all columns. Phosphate, in combination with low Ca-concentrations lowered As-removal, but had a slightly positive effect in combination with high Ca-concentrations. U-removal was only 10-70%, but showed similar trends. The drop in performance over time can be explained by decreasing release of iron to solution due to formation of layers of Fe(III)-phases and calcite covering the iron surface. Mobile corrosion products contained ferrihydrite, Si-containing hydrous ferric oxides, and amorphous Fe-Si-P phases. Comparisons with another type of ZVI-filter (SONO-filter) were used to evaluate filter design parameters. Higher ZVI surface areas and longer contact times should lead to satisfactory As- removal with Kanchan-type filters.

EN14020  Accepted 25 May 2014
 
© CSIRO 2014



Legal & Privacy | Contact Us | Help

CSIRO

© CSIRO 1996-2014