Tag Archives: ENP

Computer modeling of engineered nanoparticles in surface water, the NanoDUFLOW model

A June 4, 2015 news item on phys.org features research that could be very helpful in understanding the impact that engineered nanoparticles (ENP) have on the water in our environment,

Researchers of Wageningen University (Netherlands) provide the world’s first spatiotemporally explicit model that simulates the behaviour and fate of engineered nanoparticles (ENPs) in surface waters. Wageningen researcher Bart Koelmans: “This is important in order to assure safe nanotechnology. We do need to have an assessment of the risks of ENPs to man and the environment.”

Nanotechnology is developing fast, with the fast growing emission of less than 100 nm engineered nanoparticles as a consequence. ENPs are hard to measure in the environment so that exposure assessments have to rely on modelling. Previous models could only predict average background concentrations on a continental or national scale.

A June 3, 2015 Wageningen University press release, which originated the news item, describes the computer model,

The new NanoDUFLOW model however, developed by Joris Quik, Jeroen de Klein and Bart Koelmans and recently described in Water Research magazine, is capable of simulating the concentrations of ENPs, and their homo- and heteroaggregates in space and time, for any hydrological flow regime of a river. Under the hood of NanoDUFLOW is an ‘engine’ that calculates all relevant interactions among 35 types of particles including the ENPs, and that decides upon aggregation, settling or prolonged flow in the river. The rate of these interactions depends on the flow conditions in the river, which are calculated in the hydrology module of NanoDUFLOW. This module can be set to match the channel structure of any catchment as defined by the user, allowing for a great flexibility.

Development of the model

Development of the model took a long and winding road. ENPs are emerging chemicals with unique properties, which implies that some new process descriptions needed to be developed. One of the main parameters in this new type of models is the attachment efficiency. The attachment efficiency is the chance that two particles stay together when they collide, a chance that depends on the nature of the colliding particles and the chemistry of the water. A smart calculation method needed to be developed that enabled the estimation of the attachment efficiency from laboratory experiments with ENPs and natural particles and waters collected in the field.

Using NanoDUFLOW for the risk assessment of nanomaterials

In order to assure safe nanotechnology, society calls for an assessment of the risks of ENPs to man and the environment. A risk assessment for ENPs requires an assessment of ENP exposure, and of the effects caused by ENPs, which then can be compared in a risk characterisation. Whereas previous screening-level models still may be first choice for lower tiers in the risk assessment, NanoDUFLOW is believed to be useful for higher tiers of the risk assessment, where site specific risks need to be addressed. Simulations with NanoDUFLOW showed the occurrence of clear ENP contamination ‘hot spots’ in the water column and in sediments. Furthermore, NanoDUFLOW was capable of simulating the speciation of ENPs over different size fractions. This speciation defines the ecotoxicologically relevant fractions of ENPs, for a variety of species traits. Also in this respect NanoDUFLOW will add to refining the risk assessment for ENPs.

Here’s a link to and a citation for the paper,

Spatially explicit fate modelling of nanomaterials in natural waters by Joris T. K. Quika, Jeroen J.M. de Klein, & Albert A. Koelmans. Water Research Volume 80, 1 September 2015, Pages 200–208  doi:10.1016/j.watres.2015.05.025

This paper is behind a paywall.

Inaugural workshop using *nanomaterials for environmental remediation being held in Louisiana

Participants at the Nano-4-Rem (nanomaterials for environmental remediation) aNsseRS workshop will be visiting the Southeastern Louisiana University in Hammond in early June 2013. From the Nov.  6, 2012 news item on Nanowerk,

An inaugural workshop on the safe use of nanomaterials in environmental remediation will be held at Southeastern Louisiana University June 5-7, 2013.

With increased use of nanotechnology and nanomaterials in the cleanup of hazardous sites, there is now a growing body of evidence that exposure to these materials may have adverse health effects, said conference organizer Ephraim Massawe, assistant professor of occupational safety, health and environment.

“The applications and results of nano-enabled strategies and methods for environmental remediation are increasingly promising,” Massawe said. “The challenge is ensuring that such applications are both safe and sustainable.”

There is more information on Southeastern Louisiana University’s Nano-4-Rem aNsseRS webpage,

Background: Groundwater or soil contamination is present at most Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and Resource Conservation and Recovery Act (RCRA) corrective action sites. Traditional technologies, such as pump-and-treat (P&T) and permeable reactive barriers (PRBs), have been used for decades to remediate such sites. In recent years, remediation strategies involving engineered nanoparticles (ENPs) such as zero-valent iron and titanium dioxide have been demonstrated as viable time-saving and cost-effective alternatives to traditional remediation. In addition, advances in nanotechnology-enabled assessment and monitoring methods such as nano-sensors may support more extensive, reliable, and cost effective assessment and management of remediation activities.

At the same time that applications of nano-enabled strategies and methods for environmental remediation are increasingly promising, there is a growing body of evidence linking exposure to certain nanomaterials with adverse health effects in animals at the laboratory scale. The challenge is to ensure that such applications are both safe and sustainable. …

Workshop Objectives: This is the first national workshop that provides an opportunity for representatives from the environmental remediation community, industry, academia, and government to:

  • Share their perspectives, pose questions, and develop ideas for design of good guidelines, selection criteria, and work practices to support safe and sustainable nano-enabled environmental remediation;
  • Become acquainted with other U.S. nanotechnology stakeholders, including vendors, transporters, and contractors of the remediation sites and communities; and
  • Share case studies of nano-enhanced clean up technologies, including selection criteria for alternative remediation strategies and methods, job planning, job tasks, and nanomaterial handling practices.

Furthermore, in the context of nanoinformatics (Nanoinformatics 2020 Roadmap), the workshop will present:

  • Occupational and environmental regulatory issues as they relate to remediation, synthesis and characterization, and application of nanoinformatics for safe and sustainable use of nanomaterials during remediation;
  • Fate and transport of nanomaterials during and after remediation;
  • Risks, including contributions from both toxicological properties of nanomaterials (hazard) and potentials for occupational and environmental exposure, where hazard x exposure = risk;
  • Results of the recent nanoinformatics survey of state agencies and programs described on the workshop website; and
  • Opportunities for developing and sustaining continuing advances and collaborations.

Call for Presenters and Deadlines: Participants are invited from the industry; site contractors, nanomaterial vendors; laboratories that synthesize and characterize ENPs for environmental remediation; regulatory authorities (local, state, and federal government) and academia (faculty and students). Presenters should submit titles and abstracts for podium or poster presentations by December 14, 2012. The workshop or program schedule will be finalized by February 20, 2013. Event date: June 5-7, 2013. Students are encouraged to submit proposals for podium or poster presentations. “Best student” poster and presentation awards will be given. Information about this workshop can also be found at http://cluin.org [a US Environmental Protection Agency ‘office’].

The Nov. 7, 2012 news release from Southeastern Louisiana University which originated the news item (Nanowerk seems to have posted the item before the release was posted on the university website) provides more detail,

The event, “Nano-4-Rem-Anssers 2013: Applications of Nanotechnology for Safe and Sustainable Environmental Remediations,” is one of the first of its kind in the Southeast which has been designed to provide an opportunity for involved parties to share perspectives, pose questions and develop ideas for generating solid guidelines for best work practices that support safe and sustainable nano-enabled environmental remediation.

Southeastern is sponsoring the event with other agencies and institutions, including the U.S. Environmental Protection Agency (EPA), the National Institute of Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA) and in conjunction with the National Nanotechnology Coordination Office (NNCO).

The program will include case studies of nano-enhanced clean up technologies, including selection criteria for alternative remediation strategies and methods, job planning and tasks, and safe material handling practices. Other issues to be discussed are updates of toxicity studies, fate and transport of nanoparticules [the French word for nanoparticles is nanoparticules ..  this seems an unusual choice for a news release from a US university but Louisiana was French at one time, so perhaps there’s a desire to retain a linguistic link?]  in soils and groundwater, and nanoinformatics.

I have written about nanoremediation before. Here are a few of the latest,

Nanoremediation techniques from Iran and from South Carolina

Canadian soil remediation expert in Australia

Phyto and nano soil remediation (part 2: nano)

* ‘nanotechnolmaterials corrected to ‘nanomaterials’ on Sept. 23, 2013.