Limnobium Laevigatum Research Articles

Development of an Environmental DNA Assay for Prohibited Matter Weed Amazon Frogbit (Limnobium laevigatum)

Environmental DNA (eDNA) is widely used for detecting target species, including monitoring endangered species and detecting the presence of invasive species. Detecting targeted species using the eDNA approach is typically carried out with species-specific qPCR assays. Amazon frogbit (Limnobium laevigatum) is classified as a State-Prohibited Matter Weed in NSW, Australia. It is a fast-growing perennial aquatic weed that outcompetes native aquatic plants, leading to a reduction in the habitats of aquatic animals. Early detection is crucial for the effective management of this species. In this study, we developed a qPCR assay for L. laevigatum based on the rpoB gene sequence. This assay was validated against 25 non-target aquatic and terrestrial species. It was found to be species-specific, with the positive signal exclusively detected in L. laevigatum. The assay was highly sensitive with the modelled detection limits of 3.66 copies of DNA/µL. Furthermore, our assay was validated using environmental samples collected from field sites with and without the presence of L. laevigatum. Our assay is an effective tool for targeted eDNA detection of L. laevigatum, which will enhance efforts to monitor and control this invasive aquatic weed.

CONSIDERATIONS UPON THE MORPHOANATOMICAL FEATURES OF DECORATIVE AQUATIC PLANTS Hydrocharis laevigata AND Lagenandra meeboldii

Two aquatic plant species were subjected to this study: Hydrocharis laevigata synonym Limnobium laevigatum (Alismatales: Hydrocharitaceae) and Lagenandra meeboldii (Alismatales: Araceae). The paper presents first insight into the microscopic aspects of cross-sections made through root, petiole and leaves of in-vitro plant L. laevigatum and Lagenandra meeboldii ‘Red’ form, biological material purchased from the Romanian market of ornamental aquarium plants. Considering the invasive potential of South American spongeplant, already well documented for other European countries, this short survey draws attention to the danger represented by releasing decorative aquatic plants from aquarium as a factor involved in a possible future spreading of this species into natural environments.

The effect of lead (Pb) on the growth rates of two aquatic macrophyte species; Limnobium laevigatum (Humb & Bonpl. ex Willd) Heine and Egeria densa Planch. grown in different experimental media

Anthropogenic causes contribute to toxic pollutants in aquatic environments and heavy metal pollution. As a heavy metal, Lead (Pb), is one of the most common causes of pollution in water. Heavy metals must be removed from the aquatic environment because they adversely affect health and all living things in each environment. In this study we aimed to determine the effects of lead (Pb) exposure on the growth rates and biomass of two aquatic macrophyte species, E. densa and L. laevigatum. Plants grown in in two different experimental media. For this purpose, both plants were exposed to 3 different concentrations of lead (1 ppm, 5 ppm, 15 ppm). Samples were measured on the 1st, 4th and 7th days, and the first and last weights of the plants were compared. Bioexperiments were run in triplicate. Positive values were observed in the growth rates of both plants, except for the negative growth rates observed on the 1st day at 1 ppm and 5 ppm lead concentrations in the pond water environment. Both plants showed positive growth in 25% Hoagland medium at all concentrations and days, except for the 1 ppm lead concentration, being observed for E. densa. As a result of our study, lead exposure did not significantly alter the growth rates of E. densa and L. laevigatum in the experimental media used for short-term (up tp 7 days) durations.

Bioaccumulation of heavy metals using aquatic plants in wastewater

Heavy metals are very harmful to the environment if present in excessive concentrations and will have an effect on humans if they interact directly. Knowing the findings of heavy metal bioaccumulation in aquatic plants when reducing pollutants in liquid waste is the main goal of this study. Various types of data were developed and analyzed to answer the specific goals set through the EBSCO, ProQuest, and Science Direct Search Engine, by looking at several parameters. Bioaccumulation data for aquatic plants in liquid waste were obtained from five articles that met the criteria. The findings showed that there are six types of plants that can be used as heavy metal bioaccumulators in wastewater, including Limnobium laevigatum, Salvinia auriculata, Lemna minor, Colocasia esculenta, T. latifolia, and T. palustris. Data was also obtained that most research was carried out using liquid waste originating from within the city with a research time ranging from 1-45 days. The heavy metals that were most commonly accumulated in these plants were Zn, Pb, Cr, Ni, Cu, Fe, Mn, and Cd. It can be concluded that bioaccumulation using aquatic plants is very reliable for various types of heavy metals that can be removed.

Hydrocharis laevigata in Europe.

Hydrocharis laevigata (Humb. & Bonpl. ex Willd.) Byng & Christenh. [= Limnobium laevigatum (Humb. & Bonpl. ex Willd.) Heine], Hydrocharitaceae, is a floating-leaf aquatic plant that is native to inland South America. It is an invasive species in several parts of the world. Reports of its presence in Europe have been recently published: naturalised populations occur in three locations on the Iberian Peninsula. The literature also contains records of the species in Hungary and Poland. In addition, it has been observed in Sweden, Belgium, and the Netherlands. H. laevigata is highly adaptable and can profoundly transform habitat conditions in its invasive range, causing major issues for ecosystem conservation and human activities. Until recently, H. laevigata was not to be found in natural environments in Europe. Factors explaining its spread include its use as an ornamental plant, the eutrophication of inland waters, and the effects of global warming. With a focus on Europe, this short communication provides information on the species' distribution, taxonomy, biology, habitat, and negative impacts.

Study of the Phytoextraction and Phytodegradation of Sulfamethoxazole and Trimethoprim from Water by Limnobium laevigatum

Phytoremediation is an environmentally friendly and economical method for removing organic contaminants from water. The purpose of the present study was to use Limnobium laevigatum for the phytoremediation of water from sulfamethoxazole (SMX) and trimethoprim (TRI) residues. The experiment was conducted for 14 days, in which the loss of the pharmaceuticals in water and their concentration in plant tissues was monitored. Determination of SMX and TRI was conducted using liquid chromatography coupled with tandem mass spectrometry. The results revealed that various factors affected the removal of the contaminants from water, and their bioaccumulation coefficients were obtained. Additionally, the transformation products of SMX and TRI were identified. The observed decrease in SMX and TRI content after 14 days was 96.0% and 75.4% in water, respectively. SMX removal mainly involved photolysis and hydrolysis processes, whereas TRI was mostly absorbed by the plant. Bioaccumulation coefficients of the freeze-dried plant were in the range of 0.043-0.147 for SMX and 2.369-2.588 for TRI. Nine and six transformation products related to SMX and TRI, respectively, were identified in water and plant tissues. The detected transformation products stemmed from metabolic transformations and photolysis of the parent compounds.

The Use of Chlorophyll a fluorescence as a Marker for the Stress Detection in situ Bioassays with Limnobium laevigatum

The aim of this study was to evaluate the use of the Fluorescence of chlorophyll a (FChla) as a marker for stress detection in bioassays with Limnobium laevigatum. Therefore, three tests were carried out: 1) in the laboratory; 2) in situ in a polluted aquatic environment; 3) in situ in a preserved aquatic environment. To diagnose the environmental status of aquatic environments, physical and chemical parameters were measured using a Multiparameter probe (Hanna, Hi 9828). FChla was measured and calculated using the PAM-2500 Fluorometer (Pulse Amplitud Modulated, Heinz Walz, GmB) and the JIP test. The chlorophyll a extraction and analysis was carried out according to the methodology proposed by Porra (2002). The data set was submitted to statistical analysis by generalized linear models (GLM) with normal and gamma distribution with functions of Identity and Log binding. The chlorophyll a fluorescence using the JIP test parameters was able to detect changes in the physiological conditions of the macrophyte Limnobium laevigatum after in situ ecotoxicological assays in preserved and anthropized aquatic environments. This type of spectroscopy can be used as a marker to indicate degrees of pollution in aquatic environments. It was that L. laevigatum, a species not conventionally used yet in bioassays in the field of aquatic ecotoxicology, is sensitive to changes in environmental conditions. Keywords: OJIP Test. Energy Dissipation. Photosynthesis. Macrophyte. Resumo O objetivo deste estudo foi avaliar o uso da Fluorescência da clorofila (FChla) a como marcador para detecção de estresse em bioensaios com Limnobium laevigatum. Para tanto, foram realizados três ensaios: 1) em laboratório; 2) in situ em um ambiente aquático poluído; 3) in situ em um ambiente aquático preservado. Para diagnosticar o status ambiental dos meios aquáticos foram mensurados parâmetros físicos e químicos por meio de sonda Multiparâmetros (Hanna, Hi 9828). A FChla foi mensurada por meio do Fluorômetro PAM-2500 (Pulse Amplitud Modulated, Heinz Walz, GmB) e do JIP teste. A extração e análise de clorofila a foi realizada segundo a metodologia proposta por Porra (2002). O conjunto de dados foi submetido a análise estatística pelos modelos lineares generalizados (MLG) com distribuição normal e gama com funções de ligação Identidade e Log. A fluorescência da clorofila a por meio dos parâmetros do JIP teste foi capaz de detectar mudanças nas condições fisiológicas da macrófita Limnobium laevigatum após os ensaios ecotoxicológicos in situ em ambientes aquáticos preservados e antropizados. Esse tipo de espectroscopia pode ser utilizado como marcador para indicar graus de poluição em ambientes aquáticos. Concluímos que L. laevigatum, espécie ainda não convencionalmente utilizada em bioensaios na área da ecotoxicologia aquática, se apresenta sensível às mudanças em condições ambientais. Palavras-chave: Teste OJIP. Dissipação Energética. Fotossíntese. Macrófita.

Mansonia spp. population genetics based on mitochondrion whole-genome sequencing alongside the Madeira River near Porto Velho, Rondonia, Brazil.

In high abundance, females of the genus Mansonia (Blanchard) can be a nuisance to humans and animals because they are voraciously hematophagous and feed on the blood of a myriad of vertebrates. The spatial-temporal distribution pattern of Mansonia species is associated with the presence of their host plants, usually Eichhornia crassipes, E. azurea, Ceratopteris pteridoides, Limnobium laevigatum, Pistia stratiotes, and Salvinia sp. Despite their importance, there is a lack of investigation on the dispersion and population genetics of Mansonia species. Such studies are pivotal to evaluating the genetic structuring, which ultimately reflects populational expansion-retraction patterns and dispersal dynamics of the mosquito, particularly in areas with a history of recent introduction and establishment. The knowledge obtained could lead to better understanding of how anthropogenic changes to the environment can modulate the population structure of Mansonia species, which in turn impacts mosquito population density, disturbance to humans and domestic animals, and putative vector-borne disease transmission patterns. In this study, we present an Illumina NGS sequencing protocol to obtain whole-mitogenome sequences of Mansonia spp. to assess the microgeographic genetic diversity and dispersion of field-collected adults. The specimens were collected in rural environments in the vicinities of the Santo Antônio Energia (SAE) hydroelectric reservoir on the Madeira River.

Plastome phylogenomics and historical biogeography of aquatic plant genus Hydrocharis (Hydrocharitaceae)

BackgroundHydrocharis L. and Limnobium Rich. are small aquatic genera, including three and two species, respectively. The taxonomic status, phylogenetic relationships and biogeographical history of these genera have remained unclear, owing to the lack of Central African endemic H. chevalieri from all previous studies. We sequenced and assembled plastomes of all three Hydrocharis species and Limnobium laevigatum to explore the phylogenetic and biogeographical history of these aquatic plants.ResultsAll four newly generated plastomes were conserved in genome structure, gene content, and gene order. However, they differed in size, the number of repeat sequences, and inverted repeat borders. Our phylogenomic analyses recovered non-monophyletic Hydrocharis. The African species H. chevalieri was fully supported as sister to the rest of the species, and L. laevigatum was nested in Hydrocharis as a sister to H. dubia. Hydrocharis-Limnobium initially diverged from the remaining genera at ca. 53.3 Ma, then began to diversify at ca. 30.9 Ma. The biogeographic analysis suggested that Hydrocharis probably originated in Europe and Central Africa.ConclusionBased on the phylogenetic results, morphological similarity and small size of the genera, the most reasonable taxonomic solution to the non-monophyly of Hydrocharis is to treat Limnobium as its synonym. The African endemic H. chevalieri is fully supported as a sister to the remaining species. Hydrocharis mainly diversified in the Miocene, during which rapid climate change may have contributed to the speciation and extinctions. The American species of former Limnobium probably dispersed to America through the Bering Land Bridge during the Miocene.

Potential phytoremediation system using macrophyte Limnobium laevigatum to remove in situ Cr from contaminated bottom sediments

ABSTRACT The contamination of aquatic environments with heavy metals is an important issue, and in turn, it is crucial to study remediation techniques that can be applied in situ. In this work, the use of a containment system with macrophytes Limnobium laevigatum is explored in the laboratory to evaluate the remotion of Cr in contaminated sediments. The roots of the plants were placed in contact with the bottom sediment through a containment system. The concentration of Cr in macrophyte and sediment samples exposed to different exposure times (1, 4 and 7 days) was determined by laser-induced breakdown spectroscopy technique. The initial concentration of Cr in the sediment was 112 ± 5 mg/kg and decreased by 65% to the control (p < 0.05) after 24 h of exposure. The removal continued throughout the study time until reaching values of 23 ± 1 mg/kg. In macrophytes, the Cr concentration increased from 20 ± 5 mg/kg to 2066 ± 216 mg/kg after seven days of exposure. The correlation coefficient between Cr concentrations in both matrices was −0.96. Finally, the bioaccumulation factor of Cr in L. laevigatum was 95.22 ± 8.51. Therefore, the system studied could be a potential tool to remedy the bottom sediments of streams and lakes contaminated with heavy metals in situ.

Biosorption of uranium from aqueous solutions by Azolla sp. and Limnobium laevigatum.

The main goal of this study was to assess alternatives to the current challenges on environmental quality and circular economy. The former is here addressed by the treatment of radioactively contaminated solutions, and the latter by using abundant and low-cost biomass. In this paper, we examine the biosorption of hexavalent uranium (U(VI)) in a batch system using the macrophytes Limnobium laevigatum and Azolla sp. by three operational parameters: biomass dose, metal ion concentration, and contact time. Simulated solutions were firstly addressed with two biomasses, followed by studies with real liquid organic radioactive waste (LORW) with Azolla sp. The batch experiments were carried out by mixing 0.20g biomass in 10mL of the prepared solution or LORW. The total contact time employed for the determination of the equilibrium times was 240min, and the initial U(VI) concentration was 0.63mmol L-1. The equilibrium times were 15min for L. laevigatum and 30min for Azolla sp. respectively. A wide range of initial U(VI) concentrations (0.25-36mmol L-1) was then used to assess the adsorption capacity of each macrophyte. Isotherm models validated the adsorption performance of the biosorption process. Azolla sp. presented a much higher U(VI) uptake (0.474mmolg-1) compared to L. laevigatum (0.026mmolg-1). When in contact with LORW, Azolla sp. removed much less uranium, indicating an adsorption capacity of 0.010mmolg-1. In conclusion, both biomasses, especially Azolla sp., can be used in the treatment of uranium-contaminated solutions.

Aquatic Macrophytes Hosting Immature Mansonia (Mansonia) Blanchard, 1901 (Diptera, Culicidae) in Porto Velho, Rondonia State, Brazil.

High abundance of hematophagous mosquitoes of the genus Mansonia Blanchard, 1901 (Diptera: Culicidae) threatens human and domestic animal health and well-being. Knowledge of the biology of nuisance mosquito species is necessary to understand specific ecological and biological factors to enable rapid and effective monitoring measures for sustainable control programs. The establishment and dispersion of Mansonia species are associated with the occurrence of aquatic macrophytes species, which are indispensable for the development of larvae and pupae. To increase knowledge of the host plants for Mansonia immature stages in Porto Velho, Rondonia State, Brazil, specimens of four plant species, which occur across the tributaries of the Madeira River were sampled and inspected for the presence of egg batches, larvae, and pupae. A total of 1,386 larvae and pupae of Mansonia spp. were collected attached to the roots of Eichhornia crassipes (Mart.) Solms (Commelinales: Pontederiaceae), Pistia stratiotes L. (Alismatales: Araceae), and Limnobium laevigatum (Humb. and Bonpl. Ex Willd.) Heine (Alismatales: Hydrocharitaceae). The novel association of Mansonia species with L. laevigatum is presented. Egg batches of Mansonia spp. were found only on Salvinia molesta D.S. Mitch. (Salviniales: Salviniaceae). Possible differences in the roles played by E. crassipes and S. molesta in the reproductive cycle of Mansonia spp. in the surveyed area are discussed. All species of host plants including E. crassipes, P. stratiotes, S. molesta, and L. laevigatum should be considered when planning macrophyte management for the control of Mansonia species.

Preference of the Waterlily Aphid, Rhopalosiphum nymphaeae (Hemiptera: Aphididae) on Four Hostplants

Waterlily aphid Rhopalosiphum nymphaeae is one of the aphids that have many hosts, including Azolla filiculoides, Limnobium laevigatum, Monochoria vaginalis and Spirodela polyrhiza. The aim of this study was to study the effect of host shift and confirm the results of previous studies on the effect of nitrogen and carbon factors among A. filiculoides, L. laevigatum, M. vaginalis and S. polyrhiza on the level of aphid preference and number of offspring. Analysis of the nitrogen and carbon content of plants was also carried out to confirm the preference and number of offspring produced by aphids. The study began with maintaining aphids on the four tested hosts, up to the 4th generation. Twenty five individuals were randomly selected from each host, then released on the inner wall of the plastic container (14 x 7.5 x 15 cm3) which was filled with four hosts arranged side by side. Observations were made every 24 hours up to 97 hours starting from the first hour after treatment. Observations after 97 hours showed that waterlily aphids imago preferred L. laevigatum the most (49.28%), then on M. vaginalis (20.43%), S. polyrhiza (16.33%), and A. filiculoides (1.75%). Meanwhile, the number of offspring produced by each group of aphids that selected on four hosts were: 46.65 individuals on L. laevigatum, 37.8 individuals on M. vaginalis, 19 individuals on S. polyrhiza, and 0.6 individuals on A. filiculoides. The analysis showed that the highest nitrogen content was found in M. vaginalis (4.16%), followed by S. polyrhiza (3.71%), L. laevigatum (2.33%), and A. filiculoides (2.08%).

Distribución en Chile y colonización del río Cayumapu (Valdivia) por el macrófito acuático invasor Limnobium laevigatum

Limnobium laevigatum is an invasive aquatic herb that increases its range in Chile to displace native species from its place in the coastal zonation of the fresh water bodies. Seasonal biomass production and reproduction of this species are studied in the Sanctuary of Nature “Carlos Anwandter” in Valdivia, Chile. The change experienced by the coastal zonation of the river is established due to the aggressiveness of this invasive species, which was favored by the eutrophication of the waters. The average annual biomass reaches 6,140 kg/ha. The organs with the greatest contribution to biomass are the emergent leaves and the roots. Biomass production was higher in summer and lower in spring, when high values of necromass were also measured, indicating the presence of an unknown deleterious factor. The biomass of roots and emerging leaves has the same seasonal route with a decrease in spring, while the swimming leaves and the necromass show an inverse behavior. The presence of flowers and fruits was confirmed, which supports the hypothesis proposed of sexual reproduction for the Valdivian populations. Finally, a phenological diagram indicates the presence of viable fruits and seeds throughout the year.

Electrical current generation from a continuous flow macrophyte biocathode sediment microbial fuel cell (mSMFC) during the degradation of pollutants in urban river sediment.

A new type of sediment microbial fuel cell (SMFC) with floating macrophyte Limnobium laevigatum, Pistia stratiotes, or Lemna minor L. biocathode was constructed and assessed in three phases at different hydraulic retention time (HRT) for electrical current generation during the degradation of urban river sediment. The results showed a highest voltage output of 0.88 ± 0.1V, maximum power density of 80.22mWm-3, highest columbic efficiency of 15.3%, normalized energy recovery of 0.030kWhm-3, and normalized energy production of 0.005kWhm-3 in the Lemna minor L. SMFC during phase 3 at HRT of 48h, respectively. Highest removal efficiencies of total chemical oxygen demand of 80%, nitrite of 99%, ammonia of 93%, and phosphorus of 94% were achieved in Lemna minor L. system, and 99% of nitrate removal and 99% of sulfate removal were achieved in Pistia stratiotes and Limnobium laevigatum system during the SMFC operation, respectively. Pistia stratiotes exhibited the highest growth in terms of biomass and tap root system of 29.35g and 12.2cm to produce the maximum dissolved oxygen of 16.85 ± 0.2mgL-1 compared with other macrophytes. The predominant bacterial phylum Proteobacteria of 62.86% and genus Exiguobacterium of 17.48% were identified in Limnobium laevigatum system, while the class Gammaproteobacteria of 28.77% was observed in the control SMFC. The integration of technologies with the continuous flow operation shows promising prospect in the remediation of polluted urban river sediments along with the generation of electrical current.

Resource Relationships Among Foods Consumed by the Spot-Flanked Gallinule (Porphyriops melanops) in Colombia

The Spot-flanked Gallinule (Porphyriops melanops) is an endangered wetland-dwelling bird in Colombia. A field experiment was conducted to experimentally quantify the gallinule's food consumption and the nutritional relationships among the food resources it consumes, i.e., whether the abundance of one resource changed the consumption of another. Three wetland plant species were used for the experiments (Limnobium laevigatum, Hydrocotile ranunculoides, Azolla filiculoides), along with sesame seeds (Sesamum indicum) as a surrogate for a seed food source. Pairwise comparisons were made to determine food consumption when resources were equally available (first experiment), and after augmenting the most consumed resource in the previous experiment (second experiment). The gallinules behaved selectively during both experiments, and the value of the foods based on consumption was: L. laevigatum > S. indicum > H. ranunculoides > A. filiculoides. However, in the second experiment, L. laevigatum and S. indicum were equally consumed. Food preferences of the least consumed food in the first experiment indicated that in two pairwise comparisons the resources were perfect substitutes. In three pairwise comparisons the resources were treated as complementary, whereas two resources had an antagonistic relation. In conclusion, the gallinules' preferences depended on the context, and keeping mixtures of the preferred and complementary food resources available for the gallinules may improve the quality of wetlands.

Selenium nanovirus and its cytotoxicity in selenite-exposed higher living organisms

Selenium (Se) is an essential micronutrient in living organisms, having a narrow margin between essential and potentially toxic intake/exposure. Thus, the biochemistry of Se in living organisms must be studied in-depth to determine the underlying mechanism of Se cytotoxicity. In this study, we report the emergence of selenium nanovirus (SeNVs) in selenite-exposed fish (freshwater and saltwater) and plants (dryland) and its toxicity in them. SeNVs were found in both the abdomen and tail of Oryzias melastigma and saltwater Rhodeus ocellatus, which led to their death. The occurrence of the intracellular assembly of SeNVs was observed in the roots and leaves of corn Zea mays, but not in those of Limnobium laevigatum. SeNVs led to the death of Z. mays but caused chronic toxicity in L. laevigatum. SeNVs should be a system or structure that dissipates the intracellular redox gradients of the host cells, with simple information consisting Se–O, Se–N, or Se–S bond, that would ensure elemental Se ligand binding with nearly specific biomolecules in host cells, thereby maintaining their composition and stabilizing their structure. The multiple toxic effects of Se, therefore, could be the consequence of increase of entropy in the host cells caused by the intracellular assembly of SeNVs. This study may provide an insight into the underlying mechanism of Se in environmental toxicology and its applications in human health.

The Use of Spirodela polyrrhiza (Duckweed) and Eichhornia crassipes (Water Hyacinth) to Phytoremediate Wastewater in Guyana

Spirodela polyrhiza (orth. var. S. polyrrhiza) is a species of duckweed known by the common names common duckmeat,[1] greater duckweed,[2] great duckmeat,[3] common duckweed, and duckmeat. It can be found nearly worldwide in many types of freshwater habitat. S. polyrhiza is an ideal system for biofuels, bioremediation, and carbon cycling due to its aspects of fast-growing, direct contact with media, and smallest genome size (~150 Mb).[4] A comprehensive genomic study of S. polyrhiza was published in February 2014. The results provide insights into how this organism is adapted to rapid growth and an aquatic lifestyle.[5] Eichhornia crassipes, commonly known as common water hyacinth, is an aquatic plant native to the Amazon basin, and is often a highly problematic invasive species outside its native range. Water hyacinth is a free-floating perennial aquatic plant (or hydrophyte) native to tropical and sub-tropical South America. With broad, thick, glossy, ovate leaves, water hyacinth may rise above the surface of the water as much as 1 meter (3 feet) in height. They have long, spongy and bulbous stalks. The feathery, freely hanging roots are purple-black. An erect stalk supports a single spike of 8–15 conspicuously attractive flowers, mostly lavender to pink in colour with six petals. When not in bloom, water hyacinth may be mistaken for frog's-bit (Limnobium spongia)[6] or Amazon frogbit (Limnobium laevigatum). This research was conducted to study the phytoremediation effect of Spirodela polyrrhiza and Eichhornia crassipes respectively on domestic wastewater in East Bank of Essequibo, Essequibo Islands, West Bank Regions, Region Three, Canal Number Two Polder, Belle West, Guyana, South America. The analysis of the quantity of the influent and effluent wastewater residues (mg/L): Chloride, Sulphate, Phosphate, Potassium and Lead. Data was statistically analysed using: Levene`s F Test, Paired –Wise T-Test, Analysis of Variance – two way, and the Fisher`s Least Significant Difference Test using R-Studio. Data were analysed at the 95% confidence level with the p-value of 0.05. Results showed from this experiment indicated that influent wastewater was highly contaminated with Sulphate and was least contaminated with Lead; there was a statistically significant difference between the influent and effluent wastewater residues and also between the measured intervals (day 5, 10 and 15) for E. crassipes and S. polyrrhiza respectively; both aquatic species showed significant phytoremediation effect from as early as five days when tested. Results also showed that E. crassipes showed a great affinity for Sulphate throughout the measured intervals when compared to the other residues whereas S. polyrrhiza showed a great affinity for Phosphate throughout the measured intervals when compared to the other residues and the result showed that S. polyrrhiza showed a greater phytoremediation effect than E. crassipes since it removed > 90% of the residues in effluent wastewater.

All day Limnobium laevigatum inspired nanogenerator self-driven via water evaporation

Owing to its high conversion efficiency of solar energy and transformative industrial potential, solar-driven interfacial evaporation has been proposed as a promising alternative to conventional bulk heating-based evaporation, potentially reducing thermal losses and improving energy conversion efficiency. By using the process of plant transpiration, we developed here the Limnobium laevigatum inspired nanogenerator (LLN) made of multi-walled carbon nanotubes (MWNTs)-coated cellulose paper-located on Polystyrene (PS) foam that can float on water surface with high electricity generation and excellent freshwater production in water-rich locations such as lakes, rivers, and oceans at all hours of the day. LLN can achieve a high power density of over 50 mW m−2 and procedure freshwater at high evaporation rates of 1.48 kg m−2 h−1 during the daytime and 0.58 kg m−2 h−1 in the night, at an ambient temperature of 20 °C and humidity of 40%. The maximum power density of an LLN can be as high as 248.57/107.38 mW m−2 with a NaCl solution of 0.6 M under 1-sun/0-sun conditions that is expected the same value for seawater. The LLN can support useful power in offshore locations or deserted islands.

Floating aquatic plants for total nitrogen and phosphorus removal from treated swine wastewater and their biomass characteristics

In this study, the removal of nitrogen and phosphorus from the effluent of treated swine wastewater by Eichhornia crassipes, Pistia stratiotes, Limnobium laevigatum, and Lemna sp. was investigated. This study also aimed to quantify the potential biomass production and lignocellulosic composition of the floating plants cultured in the effluent. Plants were grown in treated swine wastewater effluent or Hoagland's solution. Pistia stratiotes showed the highest total nitrogen removal of 63.15% from the treated effluent. Lemna sp. showed the highest phosphorus removal of 36.15% from the treated effluent. However, Lemna sp. could not be further utilized because the plants could only be cultured for 13 days. The effluent likely had properties that inhibited the growth and nutrient uptake by the plants; further studies would be required to verify these properties. Pistia stratiotes and Eichhornia crassipes have higher tolerance than Lemna sp. to grow in treated swine wastewater. Eichhornia crassipes produced the highest biomass of 5.19 g dry weight/m2/day. Cellulose and lignin contents were higher in the Hoagland's solution treatment when compared with the effluent. However, based on an independent T-test analysis, the cellulose contents of plants grown in different media were not significantly different. Hemicellulose content was significantly different for Pistia stratiotes (p < 0.05). Finally, lignin content was significantly different for Eichhornia crassipes and Lemna sp (p < 0.05). The nutrient composition and available plant nutrients as well as other substances present in the effluent might have influenced the plant cell wall composition.