title: Application of nanoscale zero valent iron (NZVI) for groundwater remediation in Europe.
abstract: OBJECTIVE
  Nanoscale zero valent iron (NZVI) is emerging as a new option for the treatment of contaminated soil and groundwater targeting mainly chlorinated organic contaminants (e.g., solvents, pesticides) and inorganic anions or metals. The purpose of this article is to give a short overview of the practical experience with NZVI applications in Europe and to present a comparison to the situation in the USA. Furthermore, the reasons for the difference in technology use are discussed.
  
  
  METHODS
  The results in this article are based on an extensive literature review and structured discussions in an expert workshop with experts from Europe and the USA. The evaluation of the experiences was based on a SWOT (strength, weakness, opportunity, threat) analysis.
  
  
  RESULTS
  There are significant differences in the extent and type of technology used between NZVI applications in Europe and the USA. In Europe, only three full-scale remediations with NZVI have been carried out so far, while NZVI is an established treatment method in the USA. Bimetallic particles and emulsified NZVI, which are extensively used in the USA, have not yet been applied in Europe. Economic constraints and the precautionary attitude in Europe raise questions regarding whether NZVI is a cost-effective method for aquifer remediation. Challenges to the commercialization of NZVI include mainly non-technical aspects such as the possibility of a public backlash, the fact that the technology is largely unknown to consultants, governments and site owners as well as the lack of long-term experiences.
  
  
  CONCLUSIONS
  Despite these concerns, the results of the current field applications with respect to contaminant reduction are promising, and no major adverse impacts on the environment have been reported so far. It is thus expected that these trials will contribute to promoting the technology in Europe.
authors.affiliation: Technology and Society Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St Gallen, Switzerland. nicole.mueller@empa.ch
authors.forename: Nicole C
authors.initials: NC
authors.lastname: Mueller
authors.forename: Jürgen
authors.initials: J
authors.lastname: Braun
authors.forename: Johannes
authors.initials: J
authors.lastname: Bruns
authors.forename: Miroslav
authors.initials: M
authors.lastname: Černík
authors.forename: Peter
authors.initials: P
authors.lastname: Rissing
authors.forename: David
authors.initials: D
authors.lastname: Rickerby
authors.forename: Bernd
authors.initials: B
authors.lastname: Nowack
mesh_terms: D001673:Biodegradation, Environmental; D004784:Environmental Monitoring / Q000379:methods*; D004787:Environmental Pollution / Q000032:analysis; D005060:Europe; D060587:Groundwater / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010865:Pilot Projects; D012989:Soil Pollutants / Q000032:analysis; D014481:United States; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D007501:Iron