Application of Lemna minor in site remediation strategies (R-10194)

This PhD project deals with phytoremediation: the development of an eco-friendly and cost-effective technology to remove radioactive pollution from waste water using the aquatic plant Lemna minor (duckweed). A literature review on the potential of using photosynthetic organisms for remediation of radioactively contaminated water, revealed a small number of good quality studies for a limited amount of radionuclides. Most studies are performed under controlled laboratory conditions rather than under realistic conditions or on an industrial scale. The final result and success of a phytoremediation application is known to be influenced by the physicochemical and biological characteristics of the plant species together with environmental factors such as pH, cations (e.g. K+, Na+, Ca2+), anions (e.g. PO43-, CO32-), radionuclide concentration and speciation, growth conditions (e.g. light, nutrients, temperature), set-up (e.g. biomass/water ratio, contact time). Based on available literature and recent studies, Lemna minor has the ability to remediate radioactively contaminated water, but the final result is dependent on the scenario. The optimum conditions under which Lemna minor can be used to remove radio-pollutants from waste water will be established from several detailed experimental studies by investigating removal efficiency, metal uptake and bio-concentration factors under a variety of chemical and environmental influences. The results will be used in the mathematical modelling approach, whereby the outcome of a Lemna-oriented system based on the laboratory results can be predicted. Several processes will be included and the modelling will help guide the laboratory experiments, and vice versa. Going beyond the laboratory experiments and trying to understand and model the system will contribute to bridge the gap between laboratory studies and field applications. In the end, the outcome of a Lemna-oriented remediation system will be validated with real polluted water and compared with conventional waste water treatment techniques. In addition, by generating new understanding on the plant uptake of radionuclides in aquatic environments, the project is expected to yield important benefits for impact assessments of humans and the environment, whilst introducing new environmentally friendly depollution techniques for remediation projects.

Keywords:Lemna minor, PHYTOREMEDIATION, Radionuclides

Disciplines:Soil biology, Soil sciences, challenges and pollution not elsewhere classified