Pistia Research Articles

Ecological Engineering System Using Floating Macrophytes for the Treatment of Domestic Wastewaters

Water scarcity is a global issue due to the rapid increase in population and overexploitation of resources, which endures an imbalance between availability and demand of bluewater footprint. As a part of the Sustainable Development Goal (Goal 6: Clean Water and Sanitation), the present study designs an Ecologically Engineered System (EES) in this context. The SDGs goals were developed and had the targets for restoring and maintaining ecosystems to provide water-related services and prevent water scarcity problems. The targets indicate the need to integrate ecosystem values into planning, development processes, and strategies for reducing water scarcity. A semi pilot EES was designed with three tanks setup such as floating macrophytes (water hyacinth tank 1), submerged plants (water thymes tank 2), and emergent plants (water lettuce tank 3). The reactor was operated using domestic wastewater in a continuous mode with a flow rate of 20 l/d. Treatment performance was monitored in terms of COD, nutrients, sulphates, turbidity, etc. The study infers that after several cycles of operation, the system was well-optimized for wastewater treatment. Enhanced COD removal efficiency of 71% was observed in addition to other pollutants. The study hypothesized that EES could be an effective strategy to restore the water bodies.

Freshwater Macrophytes: A Potential Source of Minerals and Fatty Acids for Fish, Poultry, and Livestock.

The freshwater macrophytes are abundant in tropical and subtropical climates. These macrophytes may be used as feed ingredients for fish and other animals. The nutritional value of twelve freshwater-cultured macrophytes was evaluated in the present study. Significantly higher crude protein (36.94–36.65%) and lipid (8.13–7.62%) were found in Lemna minor and Spirodela polyrhiza; ash content was significantly higher in Hydrilla verticillata, Wolffia globosa, and Pistia stratiotes (20.69–21.00%) compared with others. The highest levels of sodium, magnesium, chromium, and iron levels were recorded in P. stratiotes. H. verticillata was a rich source of copper, manganese, cobalt, and zinc; the contents of calcium, magnesium, strontium, and nickel were highest in S. polyrhiza. Selenium and potassium contents were higher in Salvinia natans and W. globosa, respectively. The n-6 and n-3 polyunsaturated fatty acids (PUFAs) contents were significantly higher in W. globosa and Ipomoea aquatica, respectively compared with others. Linoleic and α-linolenic acids were dominant n-6 and n-3 PUFAs. The highest value (4.04) of n-3/n-6 was found in I. aquatica. The ratio ranged from 0.61 to 2.46 in other macrophytes. This study reveals that macrophytes are rich sources of minerals, n-6 and n-3 PUFAs.

Establishing the Correct Identity of Jalakumbhi in Ayurveda: A Critical Analysis Based on Various Literatures

Jalakumbhi is an effective Ayurvedic medicinal plant in the indigenous system of medicine which is found abundantly as a spread of a velvety carpet in mushy water bodies. This drug is known to Ayurveda practitioners since the Nighantu Kala. Jalakumbhi mentioned in Ayurvedic classics can be compared to Pistia stratiotes var. cuneata. but it is usually confused with Eichhornia crassipes also known as Pontederia crassipes thus making it controversial. This could be due to various reasons such as documentation defects in the manuscripts, same synonyms, habitat or morphology. All parts of the plant can be utilized for preparation of medicine for various diseases. The plant shows anti-thyroid, diuretic, antipyretic, anti-hemorrhoid, bronchodilator properties as well as can be used in various bleeding disorders in addition to in individuals suffering from emaciation, Sagrahani, Karnapaka, prickly heats etc. Here, an attempt is made to review the various therapeutic properties of Jalakumbhi along with its etymology, morphology and pharmacological aspects. We will also work to review and differentiate the plant which is confused as Jalakumbhi and rule out the reason behind such controversies. Various Ayurvedic and modern texts along with the latest researches have been analyzed and the concept concluded. The study shows both ayurvedic and modern explanation of this aquatic plant thus, giving correlation on the scientific basis of Ayurvedic drug Jalakumbhi and the use of it in various diseases. It will also set strong background for the drug which is mentioned as Jalakumbhi in our sacred compendiums

Elimination of toxic heavy metals from industrial polluted water by using hydrophytes

Heavy metals (HMs) are frequently detected in wastewaters, especially in industrial discharges. Phytoremediation is one of the promising low cost, environmental friendly and efficient technique to remove HMs from industrial wastewater. The current research was carried out to investigate the ability of constructed wetland (CW) for the removal of HMs including copper (Cu), cadmium (Cd), lead (Pb), nickel (Ni) and chromium (Cr) from local wastewater of industries by using two local common hydrophytes species Pistia stratiotes and Lemna Gibba. After 45 days cultivation, the concentration of HMs reduced to 0.25–0.90 mg/L and 0.78–1.4 mg/L from 5 mg/L for Lemna gibba and Pistia stratiotes, respectively. The HMs removal efficiency ranged from 82% to 95% for Lemna gibba and 72%–84.4% for Pistia stratiotes. The accumulation of HMs in roots are always higher than that in aerial part including stems and leaves for both plants. The accumulation of HMs in roots of Lemna gibba ranged from 4.3 to 4.7 mg/kg and, 1.85–3.9 mg/kg in aerial part. The corresponding values were 3.9–4.7 mg/kg and, 1.75–3.3 mg/kg for Pistia stratiotes. Results of health risk models including the average daily intake (ADI), hazard quotient (HQ) and cancer risk (CR) models indicated lower health risk of water after treatment than before treatment water. Result indicated the selected hydrophytes could be applied for HMs treatment from contaminated water.

Systematic Review of the Efficiency of Aquatic Plants in the Wastewater Treatment

Wastewater treatment uses a phytoremediation strategy that sets significant trends according to recent research from the 2019-2021 period, being one of the most efficient strategies regarding the removal of pollutants using artificial wetlands with aquatic plants. Therefore, the objective of the review article is to determine the efficiency of the aquatic plant in the phytoremediation process for the treatment of industrial, domestic, and municipal wastewater through a systematic mapping method that allows us to summarize the theoretical framework avoiding. The exclusions also have a comparative descriptive design for the study variables where it has been found that Eichhornia Crassipes is an aquatic weed that removed NO2- and NO3- up to 93% of industrial wastewater, in Pistia stratiotes it removed Turbidity (98.5%), N total (100%), P total (100%) and COD (79.18%) in household wastewater in 60 days. Finally, Azolla Filiculoides removed SO4 2- (83%), Cl (76%), PO4 3- (84%), NO3- (76%), COD (79%), BOD (63%) and EC (49%) from municipal wastewater in 21 days.

Invasion of water hyacinth and water lettuce inhibits the abundance of epiphytic algae

AbstractAimThe invasion of exotic macrophytes causes native biodiversity loss in aquatic ecosystems of China. However, the influence of invasive free‐floating macrophytes on epiphytic algal communities has rarely been reported, especially in comparison with those of native free‐floating macrophytes.RegionSouthern China.MethodsWe investigated the interrelationship between epiphytic algal communities on the roots of three free‐floating macrophytes [two invasive species (Eichhornia crassipes and Pistia stratiotes) and one native species (Hydrocharis dubia)] and environmental factors in 40 natural freshwater ecosystems throughout southern China. We also tested the relationship between allelochemicals from the macrophytes and epiphytic algae. A mesocosm experiment was conducted to verify the discoveries of the field investigation.ResultsThe abundance of epiphytic algae on the invasive macrophytes was lower than that on the native species in the field investigation and mesocosm experiment. Macrophyte traits were the main factor explaining the epiphytic algal abundance in both the field investigation and mesocosm experiment. In linear models, the slopes of epiphytic algal abundance were lower across gradients of native macrophyte biomass and coverage than across gradients of invasive macrophyte biomass and coverage. The allelochemical contents secreted by the invasive macrophytes were significantly higher than those secreted by the native species. The composition of allelochemicals was another factor that drove the decrease in epiphytic algal abundance. Among the allelochemicals, organic acids and alkaloids were abundant.Main ConclusionsThe inhibitory effect of two invasive free‐floating macrophytes on epiphytic algae is stronger than that of the native macrophyte H. dubia. The main reason for this finding is that the invasive macrophytes have greater biomass and occupied more space, resulting in greater limitations on spatial niches and resources. Moreover, invasive macrophytes release more allelochemicals than native macrophytes, leading to stronger inhibitory effects on epiphytic algae.

FIELD EVALUATION OF EMERGENCE TRAP DESIGN FOR MONITORING MANSONIA PRODUCTION FROM WATER LETTUCE (PISTIA STRATIOTES)

Larvae of the mosquito species Mansonia titillans and Mansonia dyari attach to the roots of floating aquatic plants, primarily water lettuce (Pistia stratiotes) and water hyacinth (Eichhornia crassipes), to obtain oxygen and avoid predators. Surveillance for these species involves a robust monitoring program that identifies Mansonia habitat and production sites. This report evaluates floating emergence trap efficiency for Mansonia surveillance and identification of production sites. Three trap designs were utilized in the evaluation trials, including standard passive emergence traps, modified (active) emergence traps containing a CDC-light trap with and without standard incandescent bulbs. Overall, the active emergence trap with light resulted in the collection of a significantly higher number of emerging mosquitoes.

Rhizofiltration of combined arsenic-fluoride or lead-fluoride polluted water using common aquatic plants and use of the ‘clean’ water for alleviating combined xenobiotic toxicity in a sensitive rice variety

Groundwater co-contamination with toxic pollutants like arsenic-fluoride or lead-fluoride is a serious threat for safe rice cultivation, since major stretches of land, involved in cultivation of this staple food crop are presently experiencing severe endemic pollution from these xenobiotic combinations. Preliminary investigations established that the combined pollutants together exerted more phytotoxicity in the widely cultivated indica rice variety Khitish, compared with that exerted by the individual contaminants. Thus, an ecologically sustainable and economically viable phytoremediative strategy was designed where three aquatic plants, viz., Azolla (water fern), Pistia (water lettuce) and Eichhornia (water hyacinth) (commonly located across the co-polluted regions) were tested for their ability to rhizofiltrate the water samples that had been polluted with arsenic-fluoride or lead-fluoride. Water lettuce exhibited the highest ability to ‘clean’ both arsenic-fluoride and lead-fluoride polluted water due to its capacity of efficient phytoextraction and phytostabilization. Irrigation of Khitish seedlings with this de-polluted water appreciably reduced malondialdehyde formation, electrolyte leakage and irreversible protein carbonylation due to suppression in NADPH oxidase activity and reactive oxygen species production, compared with those in sets grown with non-treated, arsenic-fluoride or lead-fluoride contaminated water. Oxidative injuries, cytotoxic methylglyoxal synthesis and inhibition of biomass growth were ameliorated, and chlorophyll synthesis and Hill activity were increased due to reduced bioaccumulation of xenobiotics, along with the improved uptake of vital micronutrients like iron, copper and nickel. Overall, the current investigation illustrated a cheap, farmer-friendly blueprint which could be easily promulgated to ensure safe rice cultivation even across territories that are severely co-polluted with the mixed contaminants.

Aquatic plants as niche for lay eggs and raising juveniles by freshwater fish in three swamp habitats in South Kalimantan, Indonesia

Abstract. Dharmono, Mahrudin, Irianti R, Fajeriadi H. 2022. Aquatic plants as niche for lay eggs and raising juveniles by freshwater fish in three swamp habitats in South Kalimantan, Indonesia. Biodiversitas 23: 1520-1526. Swamp is an area that is almost always waterlogged throughout the year, making it a very unique ecosystem. There is a wide variety of ecosystem services provided by swamp ecosystems, one of those is a habitat of freshwater fish, which is related to the presence of swamp vegetation. This study aimed to investigate swamp plants used as niches for freshwater fish to lay eggs and raise its offspring in three swamp areas in three regencies (i.e., Hulu Sungai Utara Regency, Tanah Laut Regency and Barito Kuala Regency) in South Kalimantan Province, Indonesia. Purposive random sampling was conducted in each swamp by observing and documenting the types of plants where fish eggs and offspring were found. We recorded 26 species of aquatic plants used by 17 species of swamp fish to lay eggs and raise offspring/fry. Eichhornia crassipes was the most widely used aquatic plant species with 100% of all freshwater fish species found (17 fish species), followed by Pistia stratiotes by 70.6% (12 fish species) and Cyperus digitatus, Lemna minor, Nelumbo nucifera, Utricularia aurea and Crinum asiaticum with each used by 52.9% (9 fish species). These plant species favored by fish need to be maintained and controlled to support the population of the fish.

Genotypic differences in response to different patterns of clonal fragmentation in the aquatic macrophytePistia stratiotes

AbstractConnected individuals (ramets) of clonal plants are frequently fragmented due to disturbance, and such clonal fragmentation may influence their growth. However, it is unclear whether different patterns of clonal fragmentation produce differential effects on plant growth and whether such differences vary with genotypes. We collected one group of connected ramets of the stoloniferous floating invasive macrophyte Pistia stratiotes from each of six provinces (Guangdong, Guangxi, Hubei, Jiangsu, Sichuan and Yunnan Provinces) of China, and assumed that these ramets belonged to different genotypes. After several generations of vegetative propagation to remove potential parental effects, new ramets (hereafter referred to as parent ramets) from each of these assumed genotypes were subjected to four patterns of clonal fragmentation, i.e., all offspring ramets produced during the experiment remained connected to their parent ramet (control), or the primary (1°), secondary (2°) or tertiary (3°) offspring ramets were disconnected from their parent ramet. We found significant growth differences among the assumed genotypes, confirming that the ramets sampled from these six provinces were from different genotypes. Compared with the control, disconnecting the 1°, 2° or 3° ramets did not significantly affect biomass of the whole clone (i.e., the parent ramet plus all offspring ramets) of P. stratiotes. Disconnecting the 1° ramets significantly increased biomass of the parental ramet of all six genotypes compared with the control. However, disconnecting the 2° or 3° ramets had little effect on biomass of the parent ramet for all genotypes except the Guangxi genotype, for which disconnecting the 2° ramets decreased biomass of the parent ramet. Disconnecting the 1°, 2° or 3° ramets had no impact on biomass or number of the 1° or the 3° ramets for any of the genotypes. However, disconnecting the 1° ramets decreased biomass of the 2° ramets for the Guangdong and Yunnan genotypes, but had no effect for the other four genotypes. We conclude that different patterns of clonal fragmentation can have different impacts on parent and offspring ramets of P. stratiotes and such an impact may vary with genotypes.

The Ribosomal DNA Loci of the Ancient Monocot Pistia stratiotes L. (Araceae) Contain Different Variants of the 35S and 5S Ribosomal RNA Gene Units.

The freshwater plant water lettuce (Pistia stratiotes L.) grows in warm climatic zones and is used for phytoremediation and biomass production. P. stratiotes belongs to the Araceae, an ecologically and structurally diverse early monocot family, but the phylogenetic relationships among Araceae members are poorly understood. Ribosomal DNAs (rDNAs), including the 35S and 5S rDNA, encode the RNA components of ribosomes and are widely used in phylogenetic and evolutionary studies of various plant taxa. Here, we comprehensively characterized the chromosomal locations and molecular organization of 35S and 5S rDNA genes in water lettuce using karyological and molecular methods. Fluorescence in situ hybridization revealed a single location for the 35S and 5S rDNA loci, each on a different pair of the species’ 28 chromosomes. Molecular cloning and nucleotide sequencing of 35S rDNA of P. stratiotes, the first representative Araceae sensu stricto in which such a study was performed, displayed typical structural characteristics. The full-length repeat showed high sequence conservation of the regions producing the 18S, 5.8S, and 25S rRNAs and divergence of the internal transcribed spacers ITS1 and ITS2 as well as the large intergenic spacer (IGS). Alignments of the deduced sequence of 18S rDNA with the sequences available for other Araceae and representatives of other clades were used for phylogenetic analysis. Examination of 11 IGS sequences revealed significant intra-genomic length variability due to variation in subrepeat number, with four types of units detected within the 35S rDNA locus of the P. stratiotes genome (estimated size 407 Mb/1C). Similarly, the 5S rDNA locus harbors gene units comprising a conserved 119-bp sequence encoding 5S rRNA and two types of non-transcribed spacer (NTS) sequences. Type I was classified into four subtypes, which apparently originated via progressive loss of subrepeats within the duplicated NTS region containing the 3’ part of the 5S rRNA gene. The minor Type II NTS is shorter than Type I and differs in nucleotide composition. Some DNA clones containing two or three consecutive 5S rDNA repeats harbored 5S rDNA genes with different types of NTSs, confirming the mosaic composition of the 5S rDNA locus.

Physiological defense and metabolic strategy of Pistia stratiotes in response to zinc-cadmium co-pollution

Pistia stratiotes is a cadmium (Cd) hyperaccumulating plant with strong bioaccumulation and translocation capacity for Cd. A hydroponic experiment was used to evaluate the combined effect of Zinc (Zn) and Cd at different concentrations on leaf growth and metabolism of P. stratiotes. This study revealed the physiological defense and metabolic strategy of responses to Zn–Cd co-pollution. With the Zn50Cd1, Zn50Cd10, Zn100Cd1, and Zn100Cd10 treatments for 9 d, the relative crown diameter, relative leave number, and ramet number of the plant had no significant difference with the control. Under the compound treatments containing Zn50Cd50 and Zn100Cd50, the activity of the glyoxalase system and amino acid metabolism in the leaves were inhibited. The leaf photosynthetic apparatus increased heat dissipation to reduce the damage to the photosystem II (PS II) reaction center caused by excess excitation energy under Zn–Cd stress. This safeguarded the balance between the absorption and utilization of light energy. Compared to the control, the Zn and Cd co-pollution for 9 d had no effect on the reduced glutathione (GSH) and oxidized glutathione (GSSG) contents. There was no effect on the dehydroascorbate reductase (DHAR) and glutathione reductase (GR) activities, but there was increased ascorbate peroxidase (APX) activity and oxidized ascorbic acid (DHA) content. These increased the antioxidant capacity of the ascorbate-glutathione (AsA-GSH) cycle. The treated plants also had increased levels of carnosol and substances related to lipid metabolism including 9, 10-Dihydroxystearate, Prostaglandin G2, Sphingosine, and 13-L-Hydroperoxylinoleic acid, maintaining the cell stability and resistance to the Zn–Cd stress.

A Review on the application of Macrophytes in Phytoremediation of Heavy metal Polluted water

Heavy metal pollution is a major source of pollution in the environment. Heavy metal pollution in ground and surface water threatens human health and the aquatic ecology. Traditional treatment approaches for removing pollutants from wastewater are typically expensive, time-consuming, harmful to the environment and inefficient. Phytoremediation is a low-cost, environmentally sustainable, emerging technology with a long-term application. The most important part of successful phytoremediation is plant species selection. Organic and inorganic contaminants are removed with great efficiency by aquatic macrophytes. Metal accumulator plants such as water hyacinth, water lettuce and duck weed as well as a few other aquatic plants, are commonly used to treat heavy-metal polluted water. In order to show the extensive applicability of phytoremediation, a comprehensive review about the aquatic macrophytes in phytoremediation has been compiled.

Evaluation of electro-assisted phytoremediation (EAPR) system for heavy metal removal from synthetic leachate using Pistia stratiotes

The highest waste generated in Malaysia is composed of municipal solid waste, which is mainly managed by landfilling. Heavy metals in leachate generated from landfill could have caused hazardous effects to human and environment. EAPR has been increasingly applied to treat soil and wastewater. This technique serves as a potential tool for remediation of real leachate. Metals (Mn, Cd, Fe, Ni, Pb, Zn) uptake by Pistia stratiotes were evaluated via flame atomic adsorption spectrophotometer. Pb and Fe could be the elements that were more efficiently removed by P. stratiotes in the EAPR system. The removal efficiency was 59.86 ± 9.98 and 56.56 ± 18.08% for Pb and Fe, respectively. EAPR significantly reduced the BOD (9.37 ± 2.36 mg/L), color (120.00 ± 5.77 PtCo), and turbidity (25.50 ± 11.96 NTU) of synthetic leachate. An obvious accumulation of heavy metals was observed at roots based on BCF and TF values. BCF values of Pb (18,999.06 ± 8,321.76) and Fe (16,090.81 ± 5,844.36) in the EAPR system were more than 103, which indicates that P. stratiotes is a hyperaccumulator. Further study on the upregulated genes is needed to comprehend the molecular basis of heavy metal stress tolerance.

Preferences Spodoptera pectinicornis as biocontrol of water lettuce (Pistia stratiotes L.) wetland weeds to various forms of feedstock

The dominance of water lettuce as one of the wetland weeds can cause a decrease in biodiversity in an ecosystem. Spodoptera pectinicornis can be a biological control agent for these weeds but requires a mass multiplication stage, so it is necessary to research feedstock in their augmentation. The research aimed to study the preferences and survival abilities of larvae S. pectinicornis to three forms of feed preparation made from water lettuce leaves. The research method had carried out in 2 stages (1) feedstocks form; an extracted water lettuce, mashed and cut into pieces (2) the addition of nutrients and preservatives to feedstocks. Observations had been made on the preferences and ability of the larvae to survive. The results showed that the larvae of S. pectinicornis had a preference and could survive on cut water lettuce feedstock, while in extracted and mashed died. The addition of nutrients and preservatives to the cut-up feed turned out to cause the larvae to stay away from the feed preparation and eventually die. Based on these, larvae S. pectinicornis only prefer to eat the feedstock in cutting form than enrich it with nutrients and preservatives.

Study on the Application of Phytoremediation of Phosphate Content to Eutrophication in Cengklik Reservoir, Boyolali Regency

Cengklik Reservoir is a reservoir for water from agricultural irrigation flows that use chemical fertilizers so that there is an increase in nutrients in the waters. Eutrophication is an environmental problem caused by an increase in nutrients such as nitrogen and phosphorus in aquatic ecosystems. Phytoremediation is a technique that is more efficient and economical than conventional techniques in degrading excess nutrients in polluted air. In phytoremediation, plants absorb air pollutants such as NO3-, NH4+ and PO43- directly. The purpose of this study was to examine the potential of aquatic plants in wastewater phytoremediation and provide recommendations for phytoremediation potential for the waters of the Cengklik Reservoir. The method used in this research is Systematic Literature Review (SLR). Based on the research that has been done, the Pistia stratiotes plant has been widely used as agricultural and domestic wastewater treatment. Pistia stratiotes has the potential to remove 80-95% of the phosphate content. So that the Pistia stratiotes plant is a suitable plant to be applied in the waters of the Cengklik Reservoir. The phytoremediation application was carried out in an inflow reservoir with a plant cover area of 75% of the phytoremediation area, and harvesting was carried out on the 14th day of treatment. The harvest can be utilized or managed by the community or related agencies to become a bioenergy generator.

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.

Tolerance mechanism and phytoremediation potential of Pistia stratiotes to zinc and cadmium co-contamination

Pistia stratiotes can not only effectively remediate eutrophic water, but also displays strong absorption and bioaccumulation abilities for heavy metals. However, it has not been well-understood how the plant resists the combined stress of heavy metals. In these experiments, the morphophysiological traits, the ascorbate-glutathione (AsA-GSH) cycle, the glyoxalase system, and the contents of zinc (Zn) and cadmium (Cd) were investigated under Zn and Cd co-pollution. The AsA-GSH cycle and glyoxalase system could coordinately alleviate the oxidative and carbonyl stress, which was identified as an important tolerance mechanism. With Zn50Cd1, Zn50Cd10, Zn100Cd1, and Zn100Cd10 treatments for 18 days, 90.75–93.69% of Zn and 88.13–96.96% Cd accumulated in the roots. Treatments with Zn50Cd50, and Zn100Cd50 for 18 days resulted in a decrease of stress tolerance and chlorophyll content in leaves, an increase in plasma membrane permeability, a massive accumulation of methylglyoxal (MG), and visible toxic symptoms. Additionally, the bioaccumulation factor (BCF) for roots and shoots and the translocation factor (TF) were >1, and the content of Cd in shoots was no <100 mg·kg−1. This indicated P. stratiotes was a Cd hyperaccumulator and have great potential for the phytoremediation of heavy metal contaminated water. Novelty statement Pistia stratiotes, a cadmium hyperaccumulator, has great application potential for the phytoremediation of zinc and cadmium co-polluted water.

Hydrophobic and dispersible Cu(I) desulfurization adsorbent prepared from Pistia stratiotes for efficient desulfurization

Improving the adsorption capacity of adsorbents is a good way to boost their desulfurization efficiency. Optimizing the dispersion of metal nanoparticles and enhancing the stability of the metal valence state are essential to maximizing the adsorption capacity of the metal-loaded desulfurization adsorbent. Pistia stratiotes can absorb the Cu in water and evenly disperse it throughout the plant, allowing the production of a highly dispersed Cu(I) adsorbent (PSAC-Cu(I)). During the usage and storage of PSAC-Cu(I), Cu(I) oxidizes to Cu(II) when it comes in contact with oxygen and water, reducing its adsorptive capacity; hence, we modified PSAC-Cu(I) hydrophobically using polydimethylsiloxane (PDMS) to generate PSAC-Cu(I)-P(200). The outcome of the two-month exposure experiments showed that only 4.7% of the Cu(I) of PSAC-Cu(I)-P(200) was oxidized in the humid atmosphere, whereas PSAC-Cu(I) was almost fully oxidized. Moreover, the dibenzothiophene adsorption capacity of PSAC-Cu(I)-P(200) in a model oil with a water concentration of 250 ppmw is 68 mg g−1, which is 1.62 times that of PSAC-Cu(I). When 10 wt% toluene was added to the model oil, the adsorption desulfurization capacity of PSAC-Cu(I)-P(200) decreased to 86.8% of the original. This shows that PSAC-Cu(I)-P(200) has good stability and excellent adsorptive desulfurization performance.

Phytotoxicity and Accumulation of Antibiotics in Water Lettuce (Pistia stratiotes) and Parrot Feather (Myriophyllum aquaticum) Plants under Hydroponic Culture Conditions

The aim of this research was to investigate the accumulation of antibiotics in two kinds of plants. The hydroponic culture solution included a mixture of antibiotics, including three commonly used antibiotics in South Korea: norfloxacin (NOR), sulfamethazine (SMZ), and tetracyclines (TC). None of these antibiotics were detected in the shoots of water lettuce plants, only in the roots. However, in parrot feather plants, antibiotics were detected in both the shoots and the roots, with higher amounts detected in the shoots than in the roots. SMZ and TC were most likely to be detected in the roots and shoots of water lettuce and parrot feather plants, and about one-third of the NOR administered was later detected in the plants. The BCF (bioconcentration factor) of antibiotics ranged from 0.24 to 0.78, while that of NOR was much lower, ranging from 0.24 to 0.38. The SMZ (0.59–0.64) and TET (0.72–0.78) exhibited higher uptake accumulation in the water lettuce tissues compared with the parrot feather plants.