Richard Collins

Australian Research Council Future Fellow

I obtained my PhD in 2002 and have since worked as a Research Engineer at the French Atomic Energy Commission, Saclay, France (2002-2005) and subsequently at the UNSW Water Research Centre in the School of Civil and Environmental Engineering since 2005. 

Research Projects

Environmental  Engineering

Coastal Lowland Acid Sulfate Soils

Over the last 10 years I have conducted applied research into managing coastal acid sulfate soils in northern NSW with the Tweed Shire Council, NSW Cane Growers’ Association and NSW Milling Cooperative.   The main research drivers are to: 1) identify acid sulfate soil hotspots within catchments; 2) devise site-specific land/drain modifications to limit acid sulfate soil problems, but maintain agricultural profitability and; 3) monitor how successful these modifications have been.  Some of the practicable outcomes from this research can be viewed at the Tweed Shire Council website (http://www.tweed.nsw.gov.au/Agriculture) or accessed through UNSWorks.

Iron Geochemistry

Coastal Lowland Acid Sulfate Soils

In addition to the applied research described above, I conduct research into the (redox) cycling of iron in coastal acid sulfate soils which drives many of the problems associated with these soils.  The transformations of iron in these soils are extremely dynamic and we have yet to formulate a complete understanding of all the processes involved.  This information could potentially be applied to devising novel and low-cost  in situ strategies to remediate disturbed acid sulfate soils.

Iron as an oxidant in mining

In many mining operations, ferric iron (Fe^III) is used as an oxidant to enhance the recovery of metals from ores.  Examples include uranium and copper heap leaching activities as well as in situ leach mining of uranium.  While the basics of the redox interplay between iron and these metals are considered to be reasonably well-understood, the generation of detailed (bio)geochemical knowledge on these processes could increase metal extraction efficiencies worth millions of dollars.

Iron as a reductant in remediation

Uranium is very insoluble when it is in its reduced form (U^IV).  Under certain conditions ferrous iron (Fe^II) can reduce uranium but the use of nanoscale zero valent iron (Fe⁰) as an in situ technique to immobilise uranium is also possible.  This research aims to better understand the conditions and mechanisms through which uranium is either reductively precipitated or structurally incorporated into secondary iron minerals upon reaction with either Fe^II or Fe⁰ and how this impacts upon the long-term immobilization of uranium at contaminated sites. 

Computational approaches to redox reactions

Determination of the thermodynamics and kinetics of many electron transfer reactions cannot be accessed through experiment.  Therefore, computational methods that facilitate quantum mechanical calculations are important tools to increase understanding of the redox reactions in the applications described above.   This is a relatively new research area that I have been developing in collaboration with Dr Kevin Rosso at Pacific Northwest National Laboratory and was initially supported by a 2012 Fulbright Fellowship.