Publications - Brett Robinson

Phytoremediation and phytomanagement

Phytoremediation/phytomanagement improves trace element (TE) contaminated sites by the immobilisation of TEs (phytostabilisation), or their extraction (phytoextraction). Phytostabilisation exploits transpiration and root-growth to immobilise contaminants by reducing leaching, controlling erosion, creating an aerobic environment in the root-zone, and adding organic matter to the substrate that binds TEs. Soil amendments can promote plant growth and enhance TE immobilisation. Phytostabilisation requires the establishment of tailored vegetation on the site that is left there in perpetuity. A succession of plant species may be used to establish the desired climax vegetation. Unlike phytoextraction, there are numerous examples of successful phytostabilisation on TE-contaminated sites.

Phytoextraction removes TEs from the soil by repeated crops of plants that accumulate large amounts of one or more target TEs in their above-ground biomass. The harvested plant material is removed from the site. There are few examples of successful phytoextraction. This technology is limited by the long period required for cleanup, the restricted number of target TEs that can be extracted, the limited depth that can be accessed by roots, and the difficulty of producing a high-biomass crop of the desired species. There is also concern about TE-accumulating plants providing an exposure pathway for toxic elements to enter the food chain. The addition of chelants to enhance plant-TE uptake, invariably increases the risk of TE leaching.

Phytoremediation technology is site specific due to the plethora of environmental variables that affect plant growth and TE mobility. Most contaminated sites contain a heterogeneous mixture of several elemental and organic contaminants. Plant-growth may be limited by other environmental variables, such as low pH, low nutrient availability, salinity, insufficient aeration or low water availability. The commercial success of phytoremediation is thus dependent on convincing decision makers that phytoremediation can satisfy environmental regulations. Obviously, field demonstrations at each site are not practical.

Our current research aims to elucidate the key mechanisms of plant-TE interactions to develop mechanistic models are required to calculate the effect of phytoremediation on TE fluxes. Central to such models is an understanding of root-TE interactions in these typically heterogeneous media.

Phytoremediation in action

The early stages of the phytoremediation of a five hectare wood waste pile in New Zealand. The trace elements of concern are boron, copper, chromium and arsenic. Details of this project can be found in Robinson et al. (2003a).

Phytoremediation potential

The Tui Mines, Te Aroha, New Zealand leach large amounts of lead and other toxic trace elements into local waterways. In the summer months, lead-contaminated dust blows into surrounding areas, polluting soils and water. This trial plot demonstrates that phytoremediation can provide a low-cost means to eliminate dust and reduce leaching.

Phytoremediation decision support system (Phyto-DSS)

A mechanistic model that calculates the effect of phytoremediation. The Phyto-DSS indicates the feasibility of phtoremediation and can be used to develop land management strategies.

Phytomanagement case studies

Kopu wood-waste pile

Disused sheep-dip site

Trial on Tui mine tailings

Trial on Werribee biosolids

Phytomanagement-related publications

General overview

Robinson BH, Bañuelos GS, Conesa HM, Evangelou MWH, Schulin R (2009). The phytomanagement of trace elements in soil. Critical Reviews in Plant Sciences 28(4), 240-266.

Robinson BH, Green SR, Mills TM, Clothier BE, van der Velde M, Laplane R, Fung L, Deurer M, Hurst S, Thayalakumaran T, van den Dijssel C (2003). Phytoremediation: using plants as biopumps to improve degraded environments. Australian Journal of Soil Research 41(3), 599-611.

Robinson BH, Fernández JE, Madejón P, Marañón T, Murillo JM, Green SR, Clothier BE (2003). Phytoextraction: an assessment of biogeochemical and economic viability. Plant and Soil 249(1), 117-125.

Robinson BH, Schulin R, Nowack B, Roulier S, Menon M, Clothier BE, Green SR, Mills TM (2006). Phytoremediation for the management of metal flux in contaminated sites. Forest, Snow and Landscape Research 80(2), 221-234.

Other phytoremediation publications

Tschan M, Robinson B, Johnson A, Buergi A, Schulin R. Antimony uptake and toxicity in sunflower and maize growing in Sb^III and Sb^V contaminated soil. Plant and Soil. In press. DOI: 10.1007/s11104-010-0378-2

Moradi AB , Swoboda S, Robinson B, Prohaska T, Kaestner A, Oswald SE, Wenzel WW , Schulin R (2010) Mapping of nickel in root cross-sections of the hyperaccumulator plant Berkheya coddii using laser ablation ICP-MS. Environmental and Experimental Botany 69(1), 24-31.

Fässler E, Robinson BH, Gupta SK, Schulin R (2010). Uptake and allocation of plant nutrients and Cd in maize, sunflower and tobacco growing on a contaminated soil and the effect of soil conditioners under field conditions. Nutrient cycling in Agroecosystems 136, 1-2, 49-58

Fässler E, Robinson BH, Stauffer W, Gupta SK, Papritz A, Schulin R (2010). Phytomanagement of metal-contaminated agricultural land using sunflower, maize and tobacco. Agriculture, Ecosystems and Environment 136, 49-58.

Domínguez MT Marañón T, Murillo JM, Schulin R, Robinson BH (2010). Nutritional Status of Mediterranean Trees Growing in a Contaminated and Remediated Area. Water Air and Soil Pollution 205, 305-321.

Tschan M, Robinson BH, Schulin R (2009) Antimony in the soil–plant system – a review. Environmental Chemistry 6, 106–115.

Tschan M, Robinson BH, Nodari M, Schulin R (2009). Antimony uptake by different plant species from nutrient solution, agar and soil. Environmental Chemistry 6, 144–152.

Conesa HM, Moradi AB, Robinson BH, Kühne G, Lehmann E, Schulin R (2009). Response of native grasses and Cicer arietinum to soil polluted with mining wastes: Implications for the management of land adjacent to mine sites. Environmental and Experimental Botany 65, 198-204.

Robinson BH, Bischofberger S, Stoll A, Schroer D, Furrer G, Roulier S, Gruenwald A, Attinger W, Schulin R (2008). Plant uptake of trace elements on a Swiss military shooting range: Uptake pathways and land management implications. Environmental Pollution 153, 668-676.

Domínguez MT, Marañón T, Murillo JM, Schulin R, Robinson BH (2008). Trace element accumulation in woody plants of the Guadiamar Valley, SW Spain: A large-scale phytomanagement case study. Environmental Pollution 152(1), 50-59.

Moreno FN, Anderson CWN, Stewart RB, Robinson BH (2008). Phytofiltration of mercury-contaminated water: volatilisation and plant-accumulation aspects. Environmental and Experimental Botany 62, 78-85.

Robinson BH, Green SR, Chancerel B, Mills TM, Clothier BE (2007). Poplar for the phytomanagement of boron contaminated sites. Environmental Pollution 150, 225-233.

Conesa HM, Robinson BH, Schulin R, Nowack B (2007). Growth of Lygeum spartum in acid mine tailings: response of plants developed from seedlings, rhizomes and at field conditions. Environmental Pollution. 145, 700-707.

Nowack B, Schulin R, Robinson BH (2006). A critical assessment of chelant-enhanced metal phytoextraction. Environmental Science and Technology. 40(17), 5525-5532.

Mills TM, Arnold B, Sivakumaran S, Northcott G, Vogeler I, Robinson BH, Norling C, Leonil D (2006). Phytoremediation and long-term site management of soil contaminated with pentachlorophenol (PCP) and heavy metals. Journal of Environmental Management 79, 232-241.