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Jay J. Cheng - One of the best experts on this subject based on the ideXlab platform.
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Effects of selenium on biological and physiological properties of the Duckweed Landoltia punctata.
Plant Biology, 2016Co-Authors: Yu Zhong, Jay J. ChengAbstract:Duckweed can be used for bioremediation of selenium (Se) polluted water because of its capability of absorbing minerals from growing media. However, the presence of Se in the media may affect the growth of the Duckweed. Landoltia punctata 7449 has been studied for its changes in chemical and biological properties with the presence of Se in the media. The Duckweed was cultivated over a 12-day period at different initial concentrations of selenite (Na2 SeO3 ) from 0 to 80 μmol·l(-1) . The growth rate, the organic and total Se contents, the activity of antioxidant enzymes, the photosynthetic pigment contents, the chlorophyll a fluorescence OJIP transient, and the ultrastructure of the Duckweed were monitored during the experiment. The results have shown that Se at low concentrations of ≤20 μmol·l(-1) promoted the growth of the L. punctata and inhibited lipid peroxidation. Substantial increases in Duckweed growth rate and organic Se content in the Duckweed were observed at low Se concentrations. The anti-oxidative effect occurred likely with the increases in guaiacol peroxidase, catalase and superoxide dismutase activities as well as the amount of photosynthetic pigments. However, negative impact to the Duckweed was observed when the L. punctata was exposed to high Se concentrations (≥40 μmol·l(-1) ), in which the Duckweed growth was inhibited by the selenium. The results indicate that L. punctata 7449 can be used for bioremediation of selenium (Se) polluted water when the Se concentration is ≤20 μmol·l(-1) .
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Growing Duckweed for biofuel production: a review
Plant Biology, 2014Co-Authors: W. Cui, Jay J. ChengAbstract:Duckweed can be utilised to produce ethanol, butanol and biogas, which are promising alternative energy sources to minimise dependence on limited crude oil and natural gas. The advantages of this aquatic plant include high rate of nutrient (nitrogen and phosphorus) uptake, high biomass yield and great potential as an alternative feedstock for the production of fuel ethanol, butanol and biogas. The objective of this article is to review the published research on growing Duckweed for the production of the biofuels, especially starch enrichment in Duckweed plants. There are mainly two processes affecting the accumulation of starch in Duckweed biomass: photosynthesis for starch generation and metabolism-related starch consumption. The cost of stimulating photosynthesis is relatively high based on current technologies. Considerable research efforts have been made to inhibit starch degradation. Future research need in this area includes Duckweed selection, optimisation of Duckweed biomass production, enhancement of starch accumulation in Duckweeds and use of Duckweeds for production of various biofuels.
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The production of Duckweed as a source of biofuels
Biofuels, 2012Co-Authors: Hai Zhao, Anne-marie Stomp, Jay J. ChengAbstract:Duckweed is a promising feedstock for the production of biofuels. Advantageous characteristics include rapid, clonal growth as small free-floating plants on nutrient-rich water; global adaptability across a broad range of climates; naturally high protein content; and inducible high starch content with low or no lignin, which enables other value-added products. The objective of this article is to review the published research on Duckweed cultivation in nutrient-rich wastewaters, starch enrichment in Duckweed plants and conversion of high-starch Duckweed to biofuels. Duckweed yields of 39.1–105.9 t ha-1 year-1 have been achieved using wastewater as the nutrient source, which are much higher than the yields of most other potential energy crops. Duckweed starch contents of 31.0–45.8% dry weight have been achieved after it has been subjected to nutrient starvation for 5–10 days, and up to 94.7% of the starch could be converted to ethanol using the existing technologies for corn starch conversion. Future resear...
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production of high starch Duckweed and its conversion to bioethanol
Biosystems Engineering, 2011Co-Authors: Jiele Xu, Jay J. Cheng, Annem StompAbstract:Growing high-starch Duckweed for its conversion to bioethanol was investigated as a novel technology to supplement maize-based ethanol production. Under the fall (autumn) climate conditions of North Carolina, the biomass accumulation rate of Spirodela polyrrhiza grown in a pilot-scale culture pond using diluted pig effluent was 12.4 g dry weight m−2 day−1. Through simple transfer of Duckweed plants into well water for 10 days, the Duckweed starch content increased by 64.9%, resulting in a high annual starch yield of 9.42 × 103 kg ha−1. After enzymatic hydrolysis and yeast fermentation of high-starch Duckweed biomass in a 14-l fermentor, 94.7% of the theoretical starch conversion was achieved. The ethanol yield of Duckweed reached 6.42 × 103 l ha−1, about 50% higher than that of maize-based ethanol production, which makes Duckweed a competitive starch source for fuel ethanol production.
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Functional, physiochemical, and rheological properties of Duckweed (Spirodela polyrhiza) protein.
Transactions of the ASABE, 2011Co-Authors: H. Liu, Jay J. Cheng, K. Venkateshan, S. Yan, X. S. Sun, D. WangAbstract:Duckweed contains mainly starch and protein, and protein is a coproduct of starch-based biofuel production. Plant proteins have a great potential for value-added products. However, the lack of information on Duckweed protein as a bioenergy coproduct limits its use. In this study, Duckweed protein was extracted, purified, and characterized for chemical composition, molecular weight, surface hydrophobicity, emulsion, thermal stability, and rheological properties. Duckweed (Spirodela polyrhiza) with an initial protein content of 34.5% was selected for this study, and the protein was extracted from fresh, frozen, and ambient temperature dried Duckweed. The highest extraction rate (52.1%) was obtained from fresh Duckweed, followed by ambient-dried Duckweed (45.6%) and frozen Duckweed (44.3%). The protein samples extracted from ambient-dried Duckweed had the highest purity (67.8%) of the three prepared Duckweed sources. Duckweed protein showed a low stability of the emulsion and poor emulsifying properties. Molecular weights of Duckweed protein fractions ranged from 14 kDa to more than 160 kDa. FTIR showed five distinct absorption bands related to amide A and B, amide I and II, and the carbohydrate component. The melting peak of the Duckweed protein sample was broad; it began below 50°C, covered a range of about 120°C, ended at 160°C, and degraded at 250°C. Duckweed protein is more hydrophobic than soy proteins at the same pH value, which suggests that Duckweed protein has potential to improve water resistance of protein-based adhesives.
Huub J. Gijzen - One of the best experts on this subject based on the ideXlab platform.
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The effect of a Duckweed cover on sulphide volatilisation from waste stabilisation ponds
Ecological Engineering, 2009Co-Authors: S.m. Kerstens, N.p. Van Der Steen, Huub J. GijzenAbstract:Abstract The effects of a Duckweed (DW) cover on the surface of waste stabilisation ponds on sulphide emissions were studied in a laboratory scale set-up of an anaerobic pond-reactor, followed by two algae ( A ) pond-reactors and two Duckweed ( Lemna gibba ) pond-reactors. The concentrations of various S-components were measured at different depth in the reactors, while sulphide emissions were measured at the surface. Presence of a Duckweed cover on the anaerobic pond-reactor resulted in a reduction of 99% in sulphide emission. In algae pond-reactors, sulphide emissions were negligible through chemical and biological conversion of sulphide. In the Duckweed pond-reactors, colourless sulphur bacteria ( Beggiatoa sp.) were observed on the Duckweed roots. Batch tests showed that both micro-biological and possibly chemical oxidation occurred in a typical Duckweed pond environment. The Duckweed cover reduced H 2 S volatilisation via two mechanisms, by forming a physical barrier and by providing attachment area for sulphide oxidising bacteria.
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Nitrogen recovery in an integrated system for wastewater treatment and tilapia production
The Environmentalist, 2007Co-Authors: Saber A. El-shafai, Fatma A. El-gohary, Fayza A. Naser, P. Van Der Steen, Huub J. GijzenAbstract:An integrated system, consisting of Up-flow Anaerobic Sludge Blanket (UASB)-Duckweed-tilapia ponds was used for recovery of sewage nutrients and water recycling. A UASB reactor with 40 liter working volume was used as pre-treatment unit followed by a series of three Duckweed ponds for nitrogen recovery. The treated effluent and Duckweed biomass was used to feed fishponds stocked with Nile tilapia ( Oreochromis niloticus ). The UASB reactor was fed with raw, domestic sewage at 6 h hydraulic retention time. The three Duckweed ponds were stocked with Lemna gibba and fed with UASB effluent at 15 days hydraulic retention time. Nitrogen recovery from UASB effluent via Duckweed biomass represented 81% of total nitrogen removal and 46.5% from the total nitrogen input to the system. In subsequent fishponds the nitrogen recovery from Duckweed as fish feed was in the range of 13.4–20%. This nitrogen in fish biomass represented 10.6–11.5 g N from the total nitrogen in the raw sewage fed to the UASB reactor. The growth performance of tilapia ( Oreochromis niloticus ) showed specific growth rates (SGR) in the range of 0.53–0.97. The range of feed conversion ratio (FCR) and protein efficiency ratio (PER) were 1.2–2.2 and 2.1–2.28, respectively. The results of the experiments showed total fish yield and net fish yield in the range of 17–22.8 ton/ha/y and 11.8–15.7 ton/ha/y respectively. In conclusion UASB-Duckweed-tilapia ponds provide marketable by-products in the form of Duckweed and fish protein, which represent a cost recovery for sewage treatment.
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effect of total ammonia nitrogen concentration and ph on growth rates of Duckweed spirodela polyrrhiza
Water Research, 2000Co-Authors: J R Caicedo, N.p. Van Der Steen, O Arce, Huub J. GijzenAbstract:Abstract The use of Duckweed in domestic wastewater treatment is receiving growing attention over the last few years. Duckweed-based ponds in combination with anaerobic pre-treatment may be a feasible option for organic matter and nutrient removal. The main form of nitrogen in anaerobic effluent is ammonium. This is the preferred nitrogen source of Duckweed but at certain levels it may become inhibitory to the plant. Renewal fed batch experiments at laboratory scale were performed to assess the effect of total ammonia (NH3+NH+4) nitrogen and pH on the growth rate of the Duckweed Spirodela polyrrhiza. The experiments were performed at different total ammonia nitrogen concentrations, different pH ranges and in three different growth media. The inhibition of Duckweed growth by ammonium was found to be due to a combined effect of ammonium ions (NH+4) and ammonia (NH3), the importance of each one depending on the pH.
Annem Stomp - One of the best experts on this subject based on the ideXlab platform.
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production of high starch Duckweed and its conversion to bioethanol
Biosystems Engineering, 2011Co-Authors: Jiele Xu, Jay J. Cheng, Annem StompAbstract:Growing high-starch Duckweed for its conversion to bioethanol was investigated as a novel technology to supplement maize-based ethanol production. Under the fall (autumn) climate conditions of North Carolina, the biomass accumulation rate of Spirodela polyrrhiza grown in a pilot-scale culture pond using diluted pig effluent was 12.4 g dry weight m−2 day−1. Through simple transfer of Duckweed plants into well water for 10 days, the Duckweed starch content increased by 64.9%, resulting in a high annual starch yield of 9.42 × 103 kg ha−1. After enzymatic hydrolysis and yeast fermentation of high-starch Duckweed biomass in a 14-l fermentor, 94.7% of the theoretical starch conversion was achieved. The ethanol yield of Duckweed reached 6.42 × 103 l ha−1, about 50% higher than that of maize-based ethanol production, which makes Duckweed a competitive starch source for fuel ethanol production.
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Growing High-Starch Duckweed for the Production of Fuel Ethanol
2011 Louisville Kentucky August 7 - August 10 2011, 2011Co-Authors: Jay J. Cheng, Annem StompAbstract:Corn-based ethanol production has raised much concern over its impact on food/feed supply. It is necessary, therefore, to explore novel starch sources to supplement corn starch to make the development of ethanol industry more sustainable. Duckweed is a small floating aquatic plant within the family Lemnaceae, which has been studied extensively to remove nutrients from wastewaters due to its rapid proliferation and excellent nutrient uptake ability. Duckweed is also considered as a potential starch source. Depending on the Duckweed species and the growing conditions applied, starch contents ranging from 3-75% dry weight have been reported. Studies also show that starch accumulation in Duckweed plant can be triggered at specific growing conditions especially nutrient starvation. To investigate the promise of growing high-starch Duckweed for fuel ethanol production, in this study, the Duckweed Spirodela polyrrhiza was grown using swine wastewater in a pilot-scale Duckweed culture pond. The harvested Duckweed was transferred to well water for starch accumulation. Enzymatic hydrolysis and yeast fermentation of the high-starch Duckweed biomass were carried out to evaluate the effectiveness of ethanol production. The results show that Spirodela polyrrhiza grew well in swine wastewater in summer months and simple transfer of Duckweed plants into well water for 10 days caused increases of total biomass by 81.4% and starch content by 64.9%, which resulted in a starch yield of 9.42 x103 kg ha-1. After enzymatic hydrolysis and yeast fermentation of high-starch Duckweed biomass, 94.7% of the theoretical starch conversion was achieved.
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Growing Duckweed for Bioethanol Production
2010 Pittsburgh Pennsylvania June 20 - June 23 2010, 2010Co-Authors: Weihua Cui, Jay J. Cheng, Annem StompAbstract:Duckweed is a free-floating aquatic plant that not only has shown great promise in recovering nutrients from wastewater, but also is considered as a potential energy crop that can be used for bioethanol production due to its excellent growth and starch accumulation capability. The starch content of Duckweed can be increased by manipulating growth conditions including light intensity, photoperiod, temperature, pH, and nutrient level in the culture medium. Spirodela polyrrhiza, a local Duckweed strain in North Carolina showing a great potential for starch production, was grown on nutrient-rich swine lagoon effluent for starch accumulation investigation. The effects of temperature, nutrient level, and photoperiod on the starch content of Duckweed plant were investigated. The results showed that, with the decrease of temperature from 25 to 5 oC, the starch content in Duckweed increased remarkably. With the removal of nutrients, the starch content could be increased by 59.3% within four days at 5 oC. The photoperiod test indicated that longer photoperiod favored the starch accumulation.
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growing Duckweed to recover nutrients from wastewaters and for production of fuel ethanol and animal feed
Clean-soil Air Water, 2009Co-Authors: Jay J. Cheng, Annem StompAbstract:Lemnaceae or Duckweed is an aquatic plant that can be used to recover nutrients from wastewaters. The grown Duckweed can be a good resource of proteins and starch, and utilized for the production of value-added products such as animal feed and fuel ethanol. In the last eleven years we have been working on growing Duckweed on anaerobically treated swine wastewater and utilizing the Duckweed for fuel ethanol production. Duckweed strains that grew well on the swine wastewater were screened in laboratory and greenhouse experiments. The selected Duckweed strains were then tested for nutrient recovery under laboratory and field conditions. The rates of nitrogen and phosphorus uptake by the Duckweed growing in the laboratory and field systems were determined in the study. The mechanisms of nutrient uptake by the Duckweed and the growth of Duckweed in a nutrient-limited environment have been studied. When there are nutrients (N and P) available in the wastewater, Duckweed takes the nutrients from the wastewater to support its growth and to store the nutrients in its tissue. When the N and P are completely removed from the wastewater, Duckweed can use its internally stored nutrients to keep its growth for a significant period of time. A modified Monod model has been developed to describe nitrogen transport in a Duckweed-covered pond for nutrient recovery from anaerobically treated swine wastewater. Nutrient reserve in the Duckweed biomass has been found the key to the kinetics of Duckweed growth. Utilization of Duckweed for value-added products has a good potential. Using Duckweed to feed animals, poultry, and fish has been extensively studied with promising results. Duckweed is also an alternative starch source for fuel ethanol production. Spirodela polyrrhiza grown on anaerobically treated swine wastewater was found to have a starch content of 45.8% (dry weight). Enzymatic hydrolysis of the Duckweed biomass with amylases yielded a hydrolysate with a reducing sugar content corresponding to 50.9% of the original dry Duckweed biomass. Fermentation of the hydrolysate using yeast gave an ethanol yield of 25.8% of the original dry Duckweed biomass. These results indicate that the Duckweed biomass can produce significant quantities of starch that can be readily converted into ethanol.
Kazuhiro Mori - One of the best experts on this subject based on the ideXlab platform.
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comprehensive evaluation of nitrogen removal rate and biomass ethanol and methane production yields by combination of four major Duckweeds and three types of wastewater effluent
Bioresource Technology, 2018Co-Authors: Tadashi Toyama, Masaaki Morikawa, Tsubasa Hanaoka, Yasuhiro Tanaka, Kazuhiro MoriAbstract:Abstract To assess the potential of Duckweeds as agents for nitrogen removal and biofuel feedstocks, Spirodela polyrhiza , Lemna minor , Lemna gibba , and Landoltia punctata were cultured in effluents of municipal wastewater, swine wastewater, or anaerobic digestion for 4 days. Total dissolved inorganic nitrogen (T-DIN) of 20–50 mg/L in effluents was effectively removed by inoculating with 0.3–1.0 g/L Duckweeds. S. polyrhiza showed the highest nitrogen removal (2.0–10.8 mg T-DIN/L/day) and biomass production (52.6–70.3 mg d.w./L/day) rates in all the three effluents. Ethanol and methane were produced from Duckweed biomass grown in each effluent. S. polyrhiza and L. punctata biomass showed higher ethanol (0.168–0.191, 0.166–0.172 and 0.174–0.191 g-ethanol/g-biomass, respectively) and methane (340–413 and 343–408 NL CH 4 /kg VS, respectively) production potentials than the others, which is related to their higher carbon and starch contents and calorific values.
Douglas R Tocher - One of the best experts on this subject based on the ideXlab platform.
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mass production of lemna minor and its amino acid and fatty acid profiles
Frontiers in Chemistry, 2018Co-Authors: Rina Chakrabarti, William D Clark, Jai Gopal Sharma, Ravi Kumar Goswami, Avanish Kumar Shrivastav, Douglas R TocherAbstract:The surface floating Duckweed Lemna minor (Lemnaceae) is a potential ingredient to replace the application of fish-meal in the aqua-feed. The culture technique of the Duckweed was standardized in outdoor tanks and then applied in the pond. Three consecutive experiments were conducted in tanks (1.2 m x 0.35 m x 0.3 m). In experiment 1, four different manures were used. In manure 1 (organic manure, OM) and manure 3 (2x OM), cattle manure, poultry droppings and mustard oil cake (1:1:1) were used; in manure 2 (inorganic fertilizer, IF), urea, potash, triple superphosphate were used; manure 4 (2x OM+IF) was a combination of manure 2 and manure 3. In experiment 2, manure 1 (OM) and manure 2 (IF) were used and manure 3 (OM+IF) was a combination of both manures. In experiment 3, OM and IF were selected. In pond (20 m x 10 m x 0.5 m), OM was applied. Fresh Duckweed was seeded after 5 days of manure application. In experiments 1 and 3, total production was significantly (P < 0.05) higher in OM compared to other treatments. In experiment 2, there was no significant (P < 0.05) difference in production between OM and IF. In pond, relative growth rate of Duckweed ranged from 0.422 - 0.073 g/g/day and total production was 702.5 Kg/ha/month (dry weight). Protein, lipid and ash contents were higher in Duckweed cultured in OM compared to IF. The Duckweed was a rich source of essential (39.20%), non-essential (53.64%) and non-proteinogenic (7.13%) amino acids. Among essential amino acids, leucine, isoleucine and valine constituted 48.67%. Glutamic acid was 25.87% of total non-essential amino acids. Citrulline, hydroxiproline, taurine etc. were found in the Duckweed. The fatty acid composition was dominated by PUFA, 60-63% of total fatty acids, largely -linolenic acid (LNA, 18:3n-3) at around 41 - 47% and linoleic acid (LA, 18:2n-6) at 17 - 18%. The nutritional value of Duckweeds and their production potential in the pond conditions were evaluated. Duckweed biomass may thus be used to replace commercial fish-meal that is currently used in aquaculture.
