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Light intensity alters the phytoremediation potential of Lemna minor

Departments

Coastal resources

Abstract

Lemnaceae, i.e. duckweed species, are attractive for phytoremediation of wastewaters, primarily due to their rapid growth, high nutrient uptake rates, tolerance to a broad range of growing conditions and ability to expeditiously assimilate a variety of pollutants. Light is essential for plant growth, and therefore, phytoremediation. Nevertheless, the effect of light intensity remains poorly understood in relation to phytoremediation, a knowledge gap that impedes the development of indoor, fully controlled, stacked remediation systems. In the present study, the effect of light intensity (10–850 μmol m−2 s−1) on the phytoremediation potential of Lemna minor was assessed. Plants were grown on either an optimal growth medium (half-strength Hutner’s) or synthetic dairy processing wastewater, using stationary axenic (100 mL) or re-circulating non-sterile (11.7 L) systems. The relative growth rate (RGR) of L. minor grown on half-strength Hutner’s increased proportionally with increasing light intensity. In contrast, the RGR of L. minor grown on synthetic dairy wastewater did not increase with light over an intensity range from 50 to 850 μmol m−2 s−1. On synthetic dairy wastewater, total nitrogen and total phosphorous removal also remained unchanged between 50 and 850 μmol m−2 s−1, although L. minor protein content (% fresh weight) increased from 1.5 to 2% at higher light intensities. Similar results were obtained with the larger re-circulating system. The results demonstrate interactive effects of light intensity and wastewater composition on growth and phytoremediation potential of L. minor. The data imply that light intensities above 50 μmol m−2 s−1 may not necessarily confer benefits in duckweed wastewater remediation, and this informs engineering of stacked, indoor remediation systems.

Cite this activity

Walsh É., Kuehnhold H., O’Brien S., Coughlan N.E. and Jansen M.A.K. (2021) Light intensity alters the phytoremediation potential of Lemna minor. Environmental Science and Pollution Research 28(13): 16394-16407. 10.1007/s11356-020-11792-y

Details

Research topics
Date 02.01.2021
Journal Environmental Science and Pollution Research
Issue 13
Volume 28
Pages 16394-16407
Open Access Closed Access
Open Access Status Closed Access
Eprints_link https://cris.leibniz-zmt.de/id/eprint/4804
Peer-Reviewed

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