| Abstract: | Groundwater contamination with iron (Fe) and manganese (Mn) is directly related to drink water safety. It remains challenging to simultaneously remove Fe and Mn from groundwater by conventional physical and chemical methods. Willows (Salix spp.) show promise for co-phytofiltration of Mn and Fe from groundwater. Here, a floating culture system was developed using willows for co-phytofiltration of Mn and Fe from simulated groundwater. Genotypic differences of willows were evaluated in terms of their tolerance to and accumulation of a mixture of Fe and Mn. The results showed that the growth responses of eight genotypes significantly differed to a mixture of Fe and Mn, ranging from growth inhibition to enhancement. Tolerance index analysis further indicated wide variation in the responses of willows. Tissue-specific analysis also revealed genotypic variation in the capacity of willows for translocation and accumulation of Fe and Mn. Compared with other genotypes, SB7 (Salix babylonica) and J842 (S. babylonica × Salix alba) demonstrated higher co-phytofiltration potentials for Fe and Mn based on tolerance, tissue metal concentrations, and shoot metal contents. Thus, both SB7 and J842 are candidates for co-phytofiltration of Fe and Mn from groundwater. |
