Nymphaea Rubra Research Articles

Optimizing ultrasonic-assisted extraction and untargeted metabolite identification from red water lily (Nymphaea rubra) leaves with enhanced antioxidant activity

This study aimed to optimize the ultrasonic-assisted extraction of polyphenolic compounds from red water lily (Nymphaea rubra) leaves (NRL) with heightened antioxidant activities and perform untargeted metabolite identification. Response surface methodology, employing Box-Behnken design, determined optimal conditions: 53.0 % ethanol, 32.0 min extraction time, and 53.0 °C temperature. The resulting extraction demonstrated significant total phenolic content of 45.12 ± 1.12 mgGAE/g and total flavonoid content of 44.05 ± 1.65 mgCAE/g. High-resolution mass spectrometry identified 150 secondary metabolites, encompassing phenols, flavonoids, tannins, terpenoids, and fatty acids. The optimized NRL extract exhibited notably increased radical scavenging abilities (19.21 ± 1.71 μM ASCE/g for DPPH and 24.59 ± 1.35 μM ASCE/g for ABTS) along with elevated reducing power potential (63.35 ± 4.28 μM ASCE/g for CUPRAC and 61.32 ± 2.56 μM ASCE/g for FRAP) in comparison to traditional extracts, which ranged from (7.23 ± 1.58 to 15.13 ± 1.79 μM ASCE/g, 13.29 ± 1.32 to 19.29 ± 1.69 μM ASCE/g, 22.74 ± 1.68 to 54.37 ± 3.38 μM ASCE/g, 24.14 ± 2.00 to 52.77 ± 2.33 μM ASCE/g for DPPH, ABTS, CUPRAC and FRAP, respectively). This suggests its promising potential for incorporation into antioxidant-rich functional foods. These findings underscore NRL's promise for commercial applications in the nutraceutical, food, and pharmaceutical industries.

Biological activities, identification, method development, and validation for analysis of polyphenolic compounds in Nymphaea rubra flowers and leaves by UHPLC-Q-cIM-TOF-MS and UHPLC-TQ-MS.

Nymphaea rubra belongs to the Nymphaea family and is regarded as a vegetable used in traditional medicine to cure several ailments. These species are rich in phenolic acid, flavonoids, and hydrolysable tannin. This study aimed to assess the biological activities of Nymphaea rubra flowers (NRF) and leaves (NRL) by identifying and quantifying their polyphenolic compounds using ultra-performance liquid chromatography coupled to quadrupole cyclic ion mobility time-of-flight mass spectrometry (UHPLC-Q-cIM-TOF-MS) and triple quadrupole mass spectrometry (UHPLC-TQ-MS). NRF and NRL powder was extracted with methanol and fractionated using hexane, ethylacetate, and water. Antioxidant and α-glucosidase, and tyrosinase enzyme inhibitory activities were evaluated. The polyphenolic components of NRF and NRL were identified and quantified using UHPLC-Q-cIM-TOF-MS and UHPLC-TQ-MS. The method was validated using linearity, precision, accuracy, limit of detection (LOD), and lower limit of quantification (LLOQ). Bioactive substances and antioxidants were highest in the ethylacetate fraction of flowers and leaves. Principal component analysis showed how solvent and plant components affect N. rubra's bioactivity and bioactive compound extraction. A total of 67 compounds were identified, and among them 21 significant polyphenols were quantified. Each calibration curve had R2 > 0.998. The LOD and LLOQ varied from 0.007 to 0.09 μg/mL and from 0.01 to 0.1 μg/mL, respectively. NRF contained a significant amount of gallic acid (10.1 mg/g), while NRL contained abundant pentagalloylglucose (2.8 mg/g). The developed method is simple, rapid, and selective for the identification and quantification of bioactive molecules. These findings provide a scientific basis for N. rubra's well-documented biological effects.

Comparative transcriptome analysis reveals the regulatory mechanisms of two tropical water lilies in response to cold stress

BackgroundTropical water lily is an aquatic plant with high ornamental value, but it cannot overwinter naturally at high latitudes. The temperature drop has become a key factor restricting the development and promotion of the industry.ResultsThe responses of Nymphaea lotus and Nymphaea rubra to cold stress were analyzed from the perspective of physiology and transcriptomics. Under the cold stress, Nymphaea rubra had obvious leaf edge curling and chlorosis. The degree of peroxidation of its membrane was higher than that of Nymphaea lotus, and the content of photosynthetic pigments also decreased more than that of Nymphaea lotus. The soluble sugar content, SOD enzyme activity and CAT enzyme activity of Nymphaea lotus were higher than those of Nymphaea rubra. This indicated that there were significant differences in the cold sensitivity of the two varieties. GO enrichment and KEGG pathway analysis showed that many stress response genes and pathways were affected and enriched to varying degrees under the cold stress, especially plant hormone signal transduction, metabolic pathways and some transcription factor genes were from ZAT gene family or WKRY gene family. The key transcription factor ZAT12 protein in the cold stress response process has a C2H2 conserved domain, and the protein is localized in the nucleus. Under the cold stress, overexpression of the NlZAT12 gene in Arabidopsis thaliana increased the expression of some cold-responsive protein genes. The content of reactive oxygen species and MDA in transgenic Arabidopsis thaliana was lower, and the content of soluble sugar was higher, indicating that overexpression of NlZAT12 can improve the cold tolerance of Arabidopsis thaliana.ConclusionWe demonstrate that ethylene signalling and reactive oxygen species signalling play critical roles in the response of the two cultivars to cold stress. The key gene NlZAT12 for improving cold tolerance was identified. Our study provides a theoretical basis for revealing the molecular mechanism of tropical water lily in response to cold stress.

Antidiabetic Properties of Nymphaea Species (Water Lilies): A Review

Abstract: Diabetes mellitus is a highly prevalent metabolic disease specified by increased blood glucose and impaired insulin function. Various antidiabetic drugs are currently being used, but plant sources of antidiabetic agents are of recent scientific interest as they possess multitarget effects and the most negligible side effects. Nymphaea species (water lilies) have long been traditionally taken as food and antidiabetic agents. Growing research evidence suggests that different Nymphaea species exhibit antidiabetic activity. Therefore, we took an endeavor to summarize the available scientific literature on the antidiabetic activity of the genus Nymphaea. We extensively searched in three search engines and selected 27 in vivo, 9 in vitro, and 4 in silico studies regarding antidiabetic properties of 7 Nymphaea species named Nymphaea stellata, Nymphaea pubescens, Nymphaea lotus, Nymphaea alba, Nymphaea nouchali, Nymphaea rubra, and Nymphaea odorata. All these studies coincided with the conclusion that the Nymphaea species have effective antidiabetic properties and safety. Therefore, Nymphaea species are potential candidates for evidence-based complementary and alternative medicine and integrative medicine. The species have been found to show antidiabetic properties by antihyperglycemic, antihyperlipidemic, pancreatic β-cell-regenerating, insulin secretion and sensitivity promoting, glucose uptake and metabolizing protein-expressing, intestinal glucose metabolizing enzyme inhibiting, hepatoprotective, cardiovascular protective, nephroprotective, antioxidant, and anti-inflammatory activity. A variety of antidiabetic compounds have been identified in the 7 Nymphaea species, which can be responsible for the antidiabetic activity exerted by diverse mechanisms. Future studies should be conducted on other Nymphaea species and different plant parts and diabetic parameters to investigate their antidiabetic activity and responsible phytochemical contents.

Nutraceutical Prospects and Antioxidant Activity of White and Red Water Lily Stem Available in Bangladesh

Generally, the white and red water lily cultivars' stems are consumed as vegetables in Bangladesh. However, data on the nutritional benefits and antioxidant properties of these aquatic plant’s stem are scant. Considering the aforementioned possibilities, the goal of this study was to evaluate the nutritional value, anti-nutritional factors, and antioxidant activity of two common Nymphaea species such as Nymphaea nouchali (white variety), and Nymphaea rubra (red variety) grown in Bangladesh. The proximate analysis and mineral content were determined by following AOAC methods. Crude fiber content was significantly higher in the white lily (19.56±0.68%) compared to the red cultivar (16.24±1.05%). Conversely, the red lily showed a higher value (18.52±1.01%) for ash content than the white species (15.44±0.79%). However, the varieties had no significant differences in moisture, protein, fat, and carbohydrate content. Both stems were rich in essential minerals, whereas Na and Cu were significantly higher in white water lily (WWL); however, the red water lily (RWL) stem possessed significantly copious amounts of K and P. On the other hand, there was no significant difference between two species in the case of Ca, Mg, Fe, and Zn content. The assay showed that the total phenolic contents (mg GAE/g) and total flavonoid contents (mg QE/g) were 16.51±0.05 and 15.48±02, 476±0.1 and 7.846±0.1 in white and red water lily stems respectively. In addition, the anti-nutrient screening revealed that both species were positive for saponin and tannin. Furthermore, the extract of RWL stem showed more antioxidant activity (IC50 value 28.48±0.12µg/ml) against DPPH than WWL (IC50 value 36.67±0.09 µg/ml). Thus, water lily stems can be incorporated into our diet as a potential natural source of antioxidants and vital elements.

Investigation of aquatic vascular flora at Sadullapur Upazila of Gaibandha District, Bangladesh

The present article focused on aquatic vascular plants diversity and their conservation status in natural and manmade wetlands habitats of Sadullapur Gaibandha. The study was conducted in between May 2019 to June 2020. A total of 52 aquatic plant species was recorded from Sadullapur Gaibandha in the present study. These are assigned to 35 genera under 30 families. For each species scientific name, local name, family, division, habit, habitat, use and status are provided. Ecological habitats analysis of aquatics shows variations. Among them, 37% species prefers to grow near the edge of water, 13% submerged, 11% as emergent, 11% as free floating and 28% as rooted floating in the aquatic habitat. In case of submerged species, they produce flowers on surface of the water. After pollination fruits remain under water up to maturation. Among them, 49% species used as fodder, 22% as medicinal, 4% as aquarium purpose, 9% as vegetable, 6% as edible, 10% as fish food in the study area. The population number of different aquatic plant species in habitats is not uniform. Overall analysis showed that 46% aquatic plant species in the study area found to be rare, 44% species found common and 10% species found as abundant. This status of aquatic plant species is very preliminary. Based on field observations and discussion with local people we are able to identify a good number of rare aquatic plants and also pointed some conservation measures for them in future. The investigation recorded a number of rare aquatic plant species from the study area. These are Trapa bispinosa (Singara), Nelumbo nucifera (Paddo), Nymphaea pubescens (Sada shapla), Oenanthe javanica (Panidhone), Nymphaea rubra (Lal shapla), Ottelia alismoides (Panikola), Enhydra fluctuans (Titidata) and Centrostachys aquatica (Thuash). Populations of such species in the wild are very rare because of local demand for the use. These species need to be cared for conservation.

Metabolite profiling of Nymphaea rubra (Burm. f.) flower extracts using cyclic ion mobility–mass spectrometry and their associated biological activities

Nymphaea rubra flowers (NRF) are widely used as a food and in folk medicine throughout the subtropical regions due to their health-promoting characteristics. This study characterized the phytochemical composition of various extracts/fractions of NRF by establishing a quadrupole–cyclic ion mobility–time-of-flight (Q-cIM-TOF) mass spectrometry method in both positive and negative electrospray ionization modes. Over 100 phytoconstituents were tentatively identified, among which 53 phytochemicals belonging to phenolic acids, tannins, flavonoids, terpenoids, alkaloids, xanthones, and naphthopyrones have never been documented in NRF before. Moreover, the ethyl acetate fraction of NRF demonstrated strong antioxidant potential (IC50: 9.21 ± 0.47 μg/mL in DPPH assay and 13.65 ± 0.03 μg/mL in ABTS assay) and tyrosinase, α-glucosidase, and elastase inhibition (IC50: 10.58 ± 0.20, 2.48 ± 0.02, and 38.15 ± 0.25 μg/mL, respectively). The findings highlight the value of NRF as a source of functional components and broaden its potential applications in the food and nutraceutical industries.

Nymphaea rubra

This datasheet on Nymphaea rubra covers Identity, Distribution, Further Information.

Host spectrum, reproduction, and survival of Neochetina eichhorniae (Coleoptera: Curculionidae) - A potential natural enemy for controlling water hyacinth (Eichhornia crassipes)

Neochetina eichhorniae (Coleoptera: Curculionidae) is a natural enemy of water hyacinth and its morphology as well as biology has been investigated previously. In this study, the host range of N. eichohorniae was examined using the following 7 groups of plants: Pontederiaceae (water hyacinth, Eichhornia crassipes; hastate-leaf pondweed, Monochoria hastata); food crops (rice, Oryza sativa; maize, Zea mays; sweet potato, Ipomoea batatas and cassava, Manihot esculenta); vegetables (cucumber, Cucumis sativus; mustard greens, Brassica juncea; turnip, Raphanus sativus; water spinach, Ipomoea aquatica; pepper elder, Peperomia pellucida; cabbage, Brassica oleracea var. capitata); herbaceous (boat lily, Tradescantia discolor, gotu kola, Centella asiatica, purple-heart, Tradescantia pallida); fruits (mango, Mangifera indica; longan, Dimocarpus longan; rambutan, Nephelium lappaceum); water plants (sacred lotus, Nelumbo nucifera; red water lily, Nymphaea rubra, yellow bur-head, Limnocharis flava) and industrial plants (sugarcane, Saccharum ssp.; peanut, Arachis hypogaea). The N. eichohorniae was found to be the only survivor that developed and completed its life cycle on water hyacinth. The N. eichohorniae caused only minimal damage to hastate-leaved pondweed and its life cycle was not completed on this weed. When fed with water hyacinth, N. eichohorniae female produced 358.9 eggs on average and the egg-laying period was 16 weeks. Forty three percent of eggs were laid from the 5th to the 8th weeks after females emerged from cocoons. The hatchability of N. eichohorniae eggs was 75.2% and 66.8% of the larvae could survive and became pupae. Approximately 79.1% of the pupae emerged as adults. Among the adults, the female ratio was 48.7%. These results indicated that N. eichohorniae could be considered as a natural enemy to be used for biological control of water hyacinth.

The effects of seed coat scarification, priming, and cold stratification on seed germination of a tropical night-blooming waterlily hybrid Nymphaea rubra ‘Maeploi’

The effects of seed coat scarification, priming, and cold stratification on seed germination of a tropical night-blooming waterlily hybrid <i>Nymphaea rubra</i> ‘Maeploi’

Revisiting hydropotes of Nymphaeaceae: ultrastructural features associated with glandular functions

ABSTRACT Hydropotes are specialized epidermal structures involved in water and mineral flux into and out of the plant body. We analyzed hydropote morphology of four species of Nymphaeaceae: Nymphaea caerulea, Nymphaea lotus, Nymphaea rubra, and Victoria amazonica. Leaf samples were processed following conventional techniques for plant anatomy and for scanning and transmission electron microscopy. We observed hydropotes comprising an elongated apical sharp-pointed portion with a base composed of two to three short specialized cells. In a later developmental stage the apical sharp-pointed portion was detached and the mature hydropotes comprised an upper lens-shaped cell, a bowl-shaped cell and a large foot cell. Ultrastructural analysis revealed that the lens-shaped cell possesses labyrinthine projections in its outer periclinal wall and abundant plasmodesmata in its inner periclinal wall. Several mitochondria were present in the cytoplasm of both the lens-shaped and the bowl-shaped cells. The cytoplasm of the foot cell was reduced and possessed plastids with starch grains. The ultrastructure of the hydropotes is typical of cells involved in transporting substances and corroborates their role in the flux of substances into and out of the cell. These findings contribute to a better understanding of the functioning of hydropotes and shed light on this little-explored issue.

Study of Antioxidant Activities from Antihypertension Drug Plant of the Indralaya Area

Ogan ethnic population in Indralaya, Ogan Ilir District, South Sumatra was known to have used several types of plants, there are Swietenia mahagoni, Averrhoa carambola , Syzygium samarangense, Musa acuminata , Nymphaea rubra , Syzygium polyanthum, and Andrographis paniculata for the treatment of hypertension. But, scientific information has not yet been found secondary metabolites that are responsible for providing these activities. The study began with the extraction of methanol from the seven types of plants using methanol as a solvent. Each thick extract was tested for its activity using the 1,1-diphenyl-1-picryllhydrazyl (DPPH) method. The extract which showed the highest activity (methanol extract) was subsequently carried out in vitro antihypertension test using the Angiotencyn Converting Enzyme (ACE) method. Antioxidant test results showed that the methanol extract from S. samarangense stem bark had the highest antioxidant activity with IC 50 was 83.06 μg/mL. Antihypertension test of methanol extract from S. samarangense stem bark obtained IC 50 ACE was 61.56 μg/mL. Based on the IC 50 value, it shows that S. samarangense stem bark has potential as a source of antioxidant compounds as well as a source of antihypertension compounds. Keywords: Syzygium samarangense, stem bark, antioxidant, antihypertension

GREEN SYNTHESIS OF CU(OH)2 NANOMATERIALS USING NYMPHAEA RUBRA LEAVES EXTRACT AND THEIR ANTIBACTERIAL ACTIVITY

The present study gives the eco-friendly green synthesis for the preparation of copper hydroxide nanomaterials [CuHNMs] using Nymphaea Rubra leaves extract. Bio-molecules were responsible for the formation of CuHNMs and they found to play dual role of both reducing as well as capping agents. The synthesized CuHNMs were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible spectrometer (UV-Vis), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Electron Diffraction Spectrum (EDS) and Dynamic Light Scattering (DLS).Characterization data reveals that the CuHNMs were crystalline in nature, orthorhombic in shape with an average size of 19.4 nm and Zeta Potential (Mean) was -10.0mV. The green synthesized CuHNMs were examined for its antibacterial activity and the results shows that these materials exhibit effective anti-bacterial activity against Bacillus subtilis when compared to Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. Article DOI: https://dx.doi.org/10.20319/mijst.2017.32.478492 This work is licensed under the Creative Commons Attribution-Non-commercial 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.

Nymphaea rubra Roxb. ex Andrews cultivated as an ornamental, food and vegetable in the North Eastern region of India

Nymphaearubra Roxb. ex Andrews, a wild aquatic plant, is frequently seen under cultivation in home ponds in many villages of North Eastern part of India. The flowers of the plant are used for ornamental purposes, while rhizomes, young leaves and peduncle are used as food and vegetable. The proximate nutrient content of various parts of the plant has been determined and found to be quite high. The maximum amount of protein was recorded as 23.88 % of total dry weight. Since the species is gaining an importance in the local markets of North East India as food material, an organized effort for cultivation of this species is considered as important. In this paper, the importance of N. rubra other than the ornamental uses is being highlighted and emphasis is identified for the promotion of its cultivation for future food security.

Nymphaea rubra ameliorates TNF-α-induced insulin resistance via suppression of c-Jun NH2-terminal kinase and nuclear factor-κB in the rat skeletal muscle cells.

In this work, we demonstrated insulin signaling and the anti-inflammatory effects by the chloroform fraction of ethanolic extract of Nymphaea rubra flowers in TNF-α-induced insulin resistance in the rat skeletal muscle cell line (L6 myotubes) to dissect out its anti-hyperglycemic mechanism. N. rubra enhances the GLUT4-mediated glucose transport in a dose dependent manner and also increases the tyrosine phosphorylation of both IR-β and IRS-1, and the IRS-1 associated PI-3 kinase activity in TNF-α-treated L6 myotubes. Moreover, N. rubra decreases Ser(307) phosphorylation of IRS-1 by the suppression of JNK and NF-κB activation. In conclusion, N. rubra reverses the insulin resistance by the inhibition of c-Jun NH2-Terminal Kinase and Nuclear-κB.

Immunomodulating Activity of Nymphaea rubra Roxb. Extracts: Activation of Rat Dendritic Cells and Improvement of the TH1 Immune Response

Polysaccharides play a key role in enhancing immune function and facilitating cellular communication. Here, we purified Nymphaea rubra Roxb. polysaccharides (NR-PS) by treating them with pullulanase. They were then cultured with immature dendritic cells (DCs) derived from rat bone marrow hematopoietic cells (BMHCs). After treatment with bioactive NR-PS with a degree of polymerization (DP) value of 359.8, we found that the DCs underwent morphological changes indicative of activation. CD80/86 (87.16% ± 8.49%) and MHC class II (52.01% ± 10.11%) expression levels were significantly up-regulated by this treatment compared to the controls (65.45% ± 0.97% and 34.87% ± 1.96%). In parallel, endocytosis was also reduced (167.94% ± 60.59%) after treatment with 25 μg/mL of NR-PS as measured by the medium fluorescence intensity compared to the control (261.67% ± 47.26%). Furthermore, the DCs after treatment with 25 μg/mL NR-PS showed increased IL-12 (102.09 ± 10.16 to 258.78 ± 25.26 pg/mL) and IFN-γ (11.76 ± 0.11 to 15.51 ± 1.66 pg/mL) secretion together with reduced IL-10 secretion (30.75 ± 3.35 to 15.37 ± 2.35 pg/mL), which indicates a TH1 immune response. In conclusion, NR-PS exhibits stimulatory effects on rat DCs and promotes the secretion of TH1 cytokines. Taken together, our studies are the first to show that NR-PS is an immunomodulator affecting the maturation and functioning of DCs.

Effects of submerged tropical macrophytes on flow resistance and velocity profiles in open channels

In this paper, the results of flume experiments are presented, conducted to investigate the effect of different submerged flexible plant species on flow resistance and flow patterns in open channels. Three common plant types in tropical regions were selected: Cabomba caroliniana, a quite flexible fully submerged species; Echinodorus grandiflorus, a somewhat less flexible, fully submerged species; and Nymphaea rubra, a rooted species with floating leaves. For each plant type, three different densities were tested for various discharges, water depths, and depths of plant submergence. The flow resistance was expressed in terms of the commonly used Manning coefficient n. The results indicate that among the particular plant species investigated here, the floating leaf species N. rubra exhibits the lowest flow resistance (Manning's n = 0.014), viz. less than half the values for C. caroliniana and E. grandiflorus, respectively. A detailed analysis showed that this is due to the particular plant morphology, consisting of relatively large biomass (floating leaves) with only small stem density. It was observed that the flow resistance not only strongly and inversely depends on the Reynolds number, but also on the degree of plant submergence (i.e. water depth/deflected plant height ratio), and on the density of the vegetated plant beds. It appears that the biomass/drag force ratio seems of less importance. From the measured velocity profiles, the influence of the various types of vegetation species could clearly be observed. These factors are important for the design and management of vegetated open channels in tropical urban areas like Singapore.

Genetic Variability of Thermal Nymphaea (Nymphaeaceae) Populations Based on ISSR Markers: Implications on Relationships, Hybridization, and Conservation

The globally widespread genus Nymphaea exhibits a wide range of morphological and taxonomical diversity. The intrusion of a cultivated variety by progressive propagation and its affect on aquatic habitat is demonstrated in this case study. We have studied the genetic diversity, population, and stand structure of the neophyte Nymphaea × ‘Panama Pacific’ as well as other species found in Lake Hévíz and dikes nearby using inter-simple sequence repeat (ISSR) markers. The ISSR assay revealed a low genetic variability for the small populations of Nymphaea caerulea, Nymphaea lotus var. thermalis, and a medium level for Nymphaea alba, Nymphaea rubra var. longiflora, and Nymphaea × ‘Panama Pacific’. The evolutionary genetic status of individuals found in the overlapping cultivation area of Nymphaea × ‘Panama Pacific’ and N. caerulea was affirmed to be of hybrid origin by reticulate network analysis and with morphological parameters. The Bayesian analysis of hybrid classes and the segregation of the ISSR markers also confirmed the hybrid origin of the individuals in question and revealed that they are falling into F2 or latter genotype frequency classes, indicating the viability and fertility of the hybrids. The set of analyzed species by phylogenetic network analysis of ISSR data has been divided into three major groups according to their evolutionary patterns (subg. Barachyceras, Lotos, and Nymphaea). Our results are in accordance with these three major subgenera within Nymphaea.

Equilibrium and Kinetic Studies on the Removal of Reactive Red 2 Dye from an Aqueous Solution Using a Positively Charged Functional Group of the Nymphaea rubra Biosorbent

AbstractNymphaea rubra stem was used as a low cost and easily available biosorbent for the removal of Reactive Red 2 dye from an aqueous solution. Initially, the effects of biosorbent dosage (0.2–1.0 g L–1), pH (1–6), and dye concentration (30–110 mg L–1) on dye removal were studied. Batch experiments were carried out for biosorption kinetics and isotherm studies. The results showed that dye uptake capacity was found to increase with a decrease in biosorbent dosage. Equilibrium uptake capacity was found to be greatest at a pH value of 2.0, when compared to all other pH values studied. The equilibrium biosorption isotherms were analyzed by the Freundlich and Langmuir models. The equilibrium data was found to fit very well with the Freundlich isotherm model when compared to the Langmuir isotherm model. The kinetic data was analyzed using pseudo‐first order and pseudo‐second order kinetic models. From the results, it was observed that the kinetic data was found to fit the pseudo‐second order kinetic model very well. The surface morphology of the stem of the N. rubra biosorbent was exemplified by scanning electron microscopy. Fourier transform infrared analysis was employed to confirm the existence of an amine group in the stem of N. rubra.

Removal of Chromium from Synthetic Effluent using Nymphaea rubra

AbstractIn the present work, biosorption of Cr(VI) by Nymphaea rubra was investigated in batch studies. Batch experiments were conducted to study the effect of initial sorbent dosage, solution pH and initial Cr(VI) concentration. The results showed that the equilibrium uptake capacity was increased with decrease in biomass dosage. The Cr(VI) removal was influenced by the initial chromium compound concentration. Langmuir and Freundlich adsorption isotherm models were used to represent the equilibrium data. The Freundlich isotherm model was fitted very well with the equilibrium data when compared to Langmuir isotherm model. The sorption results were analyzed for pseudo‐first order and pseudo‐second order kinetic model. It was observed that the kinetic data fitted very well with the pseudo‐second order rate equation when compared to the pseudo‐first order rate equation. Fourier transform infrared spectrum showed the presence of different functional groups in the biomass. The surface morphology of the sorbent was exemplified by SEM analysis. Aquatic weeds seem to be a promising biosorbent for the removal of chromium ions from water environment. This paper reports the research findings of a laboratory‐based study on the removal of Cr(VI) from the synthetic solution using the dried stem of N. rubra as a biosorbent.