Growth and Nutrient Removal Efficiency of Duckweed (lemna minor) from Synthetic and Dumpsite Leachate Under Artificial and Natural Conditions

Abstract, PLOS, 2019

Sustainable management of leachate produced from the dumpsite is one of the major concerns in developing countries Aquatic plants such as duckweed have the potential to remove pollutants from wastewater which can also be cost-effective and feasible options for leachate treatment. Therefore, the objective of our present study was to examine the growth and nutrient removal efficiency of duckweed (Lemna minor) on leachate. Three tests were performed each by growing lemna minor on synthetic leachate under controlled conditions and on dumpsite leachate under natural conditions. During each test, duckweed was grown in 300 ml plastic containers with a surface area of 25.8 cm². About 60 mg of fresh mass of duckweed was grown on 250 ml leachate at an internal depth of 9.5 cm. Results revealed that, in comparison to synthetic leachate, duckweed removed Chemical Oxygen Demand (COD), nitrogen (N), and phosphorous (P) more efficiently from dumpsite leachate under natural climatic conditions. However, the amounts of N and P absorbed into duckweed body mass were about 16% and 35% respectively more at synthetic leachate under controlled conditions. Maximum growth rate of duckweed (7.03 g m^-2 day^-1) was also observed for synthetic leachate in comparison to the growth rate of 4.87 g m^-2 day^-1 at dumpsite leachate. Results of this study provide a useful interpretation of duckweed growth and nutrient removal dynamics from leachate under natural and laboratory conditions.