Effect of pH on Cr(III) accumulation, biomass production and phenolic profile in two Salvinia species.

We analyzed the effect of pH on Cr(III) accumulation, biomass production, and phenolic profile of Salvinia rotundifolia and Salvinia minima plants grown in the presence of increasing concentrations of CrCl3. Biomass accumulation, metal tolerance index, and photosynthetic pigment contents indicate that Salvinia rotundifolia seems to be more tolerant of Cr(III) than S. minima at different pHs. Increased metal accumulation by Salvinia species under increasing pH could be explained by changes of the protonation status of cell wall functional groups because both the highest and the lowest pH values used in the present study were outside of the levels at which Cr(III) species start to precipitate. The metal translocation factor indicates that in buffered conditions S. rotundifolia tend to retain more Cr(III) in lacinias than S. minima, probably through the involvement of insoluble phenolics. The results of the present study could be useful to the management of solution pH to maximize the removal of Cr(III) by aquatic plants. Environ Toxicol Chem 2019;38:167-176. (c) 2018 SETAC