Below are my research papers on Duckweed. Click on the title to download the files:
Abstract
Duckweed species have been used for several years as a means for recovering nutrients from wastewater and at the same time producing feed for livestock, fish and poultry1.
We have grown the duckweed species Lemna gibba 8678 on anaerobic ally digested wastewater from a swine rearing facility at the Lake Wheeler Agricultural Research Center, Raleigh, North Carolina. The Lemna produced was dried and analyzed for dry matter, total protein, and fiber, amino acid and trace mineral composition. This composition was compared with that of soybean and fish meal and its potential value as a feed ingredient in fish and shrimp diets assessed based on this analysis. The practical value of wastewater-grown duckweed was examined based on its nutritional value in formulated diets.
Author: | Louis Landesman1*, Jiayang Chang1, Yuri Yamamoto2 and Jeremy Goodwin1. |
Date: | August 20, 2012 |
Goals and Objectives
The main purpose of my research was to determine how species of Lemnaceae
(duckweed) interact when growing in wastewater treatment systems and to see how
grazing by fish (herbivory) effected the outcome of this interaction. Results of my
research will help determine which species, or combination of species, of duckweed is
best suited for use in wastewater treatment systems and which species will produce
the most nutritious forage when grown on this wastewater.
Author: | Dr. Louis Landesman |
Date: | August 20, 2012 |
Goals and Objectives
The main purpose of my research was to determine how species of Lemnaceae
(duckweed) interact when growing in wastewater treatment systems and to see how
grazing by fish (herbivory) effected the outcome of this interaction. Results of my
research will help determine which species, or combination of species, of duckweed is
best suited for use in wastewater treatment systems and which species will produce
the most nutritious forage when grown on this wastewater.
Author: | Dr. Louis Landesman |
Date: | August 20, 2012 |
Abstract
Species of the genera Lemnaceae, or duckweeds, are floating aquatic plants that show great promise for both wastewater treatment and livestock feed
production. Research conducted in the Southern High Plains of Texas has shown that Lemna obscura grew well in cattle feedlot runoff water and
produced leaf tissue with a high protein content. A model or mathematical expression derived from duckweed growth data was used to fit data from
experiments conducted in a greenhouse in Lubbock, Texas.
The relationship between duckweed growth and the total nitrogen concentration in the mediium follows the Mitscherlich Function and is similar to that of
other plants. Empirically derived model equations have successfully predicted the growth response of Lemna obscura.
Keywords: Duckweed, Lemna, Lemnaceae, model, total nitrogen, wastewater
Author: | Dr. Louis Landesman |
Date: | August 21, 2012 |
ABSTRACT
Nitrogen and phosphorus removal from swine lagoon liquid by growing Lemna minor 8627, a promising duckweed identified in previous studies, was investigated under in vitro and field conditions. The rates of nitrogen and phosphorus uptake by the duckweed growing in the in vitro system were as high as 3.36 g m–2 day –1and 0.20 g m–2 day–1, respectively.The highest nitrogen and phosphorus removal rates in the field duckweed system were 2.11 g m–2 day –1and 0.59 g m–2 day –1,respectively. The highest observed duckweed growth rate was close to 29 g m–2 day –1in both conditions.
Wastewater concentrations and seasonal climate conditions had direct impacts on the duckweed growth and nutrient
removal in outdoor tanks. The rate of duckweed production in diluted swine lagoon liquid increased as the dilution rate
increased. Duckweed assimilation was the dominant mechanism for nitrogen and phosphorus removal from the swine lagoon
liquid when the nutrient concentration in the wastewater was low, but became less important as nutrient concentration
increased. Reasonably high light intensity and a longer period of warm temperature could result in a higher growth rate for
the duckweed. Pre–acclimation of the duckweed with swine lagoon liquid could accelerate the start–up of a duckweed system
to remove nutrients from the wastewater by preventing the lag phase of duckweed growth.
Keywords. Ammonium, Duckweed, Lemna minor, Nitrogen, Nutrient removal, Phosphorus, Swine wastewater treatment.
Author: | J. Cheng, L. Landesman, B. A. Bergmann, J. J. Classen, J. W. Howard, Y. T. Yamamoto |
Date: | August 21, 2012 |