Water Hyacinth Research Articles

Efficacy of Water Hyacinth as Growing Media for Amaranthus in Open Water Culture, Hydroponics and Land Cultivation in Kuttanad Ecosystem

A field experiment was conducted in farmer’s field in north Kuttanad during the kharif season during June-July 2023 and repeated consecutively during August-September 2023 to evaluate the efficacy of open water culture with respect to yield and growth attributes of amaranthus cultivation against deep water culture hydroponics with and without water hyacinth as medium. The experiment was laid out in a Randomized Design (CRD), comprising six treatments with four replications. The treatments were T1: Open water culture without medium, T2: Open water culture with medium, T3: Hydroponics without medium, T4: Hydroponics with medium, T5: Land cultivation with a bed of water hyacinth alone as medium and T6: Control: soil culture-KAU-POP recommended dose of nutrients. The data revealed significant differences in plant height, number of leaves, leaf length and width, leaf area index, stem girth, root length and yield. Maximum plant height was recorded in T6 (Control- soil culture-Kerala Agricultural University (KAU) -POP recommended dose of nutrients) followed by T5 (Land cultivation with a bed of water hyacinth alone as medium). Highest leaf area index, stem girth and root length were in T6, but was on par with T5. The yield of the total harvest was significantly higher in T6, but was on par with T5, which proves the efficacy of water hyacinth as a growing medium for amaranthus cultivation. The lowest yield and growth attributes were recorded by T1 (Open water culture without medium) and T3 (Hydroponics without medium).

BIOCHAR AS A POTENTIAL SOIL CONDITIONER IN SALINE PRONE COASTAL AREA OF BANGLADESH

In the coastal areas of Bangladesh, salinity restricts normal crop production and increases with the desiccation of the soil. Recently, biochar has received great attention as a soil amendment to mitigate the detrimental effects of salinity stress. In this respect, a field experiment was conducted to examine the effects of biochars on soil properties and growth of okra (Abelmoschus esculentus L.) and to identify a suitable biochar amendment for salt-affected soils in coastal areas of Bangladesh. The experiment was conducted in a randomized complete block design (RCBD) with five replications. Three types of biochar (rice straw biochar, sawdust biochar and water hyacinth biochar) were applied @ 10 t ha-1 in a silt loam soil along with the control. Results showed that biochar application to the soil enhanced plant height, leaf number, leaf area, shoot fresh weight, shoot dry weight and yield of okra as well as improving the soil quality e.g. field capacity (FC), CEC, OC, total N, available P, S, K, and Ca. The application of water hyacinth biochar improved almost all of the growth and yield attributes of okra along with most of the soil properties than that of others. The results suggest that water hyacinth biochar might be recommended as a suitable soil amendment for better crop growth and soil quality. Moreover, water hyacinth biochar had significantly (P<0.001) higher surface area (205.40 m2g-1); consequently, higher capacity in salt and water adsorption which might prevent soil desiccation. Side by side, it significantly (P<0.001) increased the soil Ca content which might replace Na+ in the root rhizosphere minimizing the Na+ uptake by plants. Taken together, water hyacinth biochar could also be the best choice of organic amendments to reduce the suppressing effect of salinity stress in coastal areas of Bangladesh.

Adsorption of Phosphate by Two-Step Synthesis of Ceramsite from Electrolytic Manganese Residue/Dredged Sludge.

Carrying out research on the management of electrolytic manganese residue (EMR) is necessary to maintain the environment and human health. The dredged sludge (DS) and water hyacinth (WH) generated from dredging projects are potential environmental threats, and therefore suitable methods need to be found for their treatment. In this study, ceramsite was prepared by a two-step low-temperature firing method using DS and EMR as raw materials, WH as a pore-forming additive, and aluminate cement as a binder for the adsorption of phosphorus from wastewater. The optimal ratio and process parameters of the ceramsite were determined by mechanical and adsorption properties. The static adsorption experiments were conducted to study the effect of ceramsite dosage and solution pH on the removal of phosphorus. At the same time, dynamic adsorption experiments were designed to consider the influence of flow rate on its actual absorption effect, to explore the actual effect of ceramsite in wastewater treatment, and to derive a dynamic adsorption model that can provide technical support and theoretical guidance for environmental management.

Utility of metagenomics for bioremediation: a comprehensive review on bioremediation mechanisms and microbial dynamics of river ecosystem.

Global industrialization has contributed substantial amounts of chemical pollutants in rivers, resulting in an uninhabitable state and impacting different life forms. Moreover, water macrophytes, such as water hyacinths, are abundantly present in polluted rivers, significantly affecting the overall water biogeochemistry. Bioremediation involves utilizing microbial metabolic machinery and is one of the most viable approaches for removing toxic pollutants. Conventional techniques generate limited information on the indigenous microbial population and their xenobiotic metabolism, failing the bioremediation process. Metagenomics can overcome these limitations by providing in-depth details of microbial taxa and functionality-related information required for successful biostimulation and augmentation. An in-depth summary of the findings related to pollutant metabolizing genes and enzymes in rivers still needs to be collated. The present study details bioremediation genes and enzymes functionally mined from polluted river ecosystems worldwide using a metagenomic approach. Several studies reported a wide variety of pollutant-degrading enzymes involved in the metabolism of dyes, plastics, persistent organic pollutants, and aromatic hydrocarbons. Additionally, few studies also noted a shift in the microbiome of the rivers upon exposure to contaminants, crucially affecting the ecological determinant processes. Furthermore, minimal studies have focused on the role of water-hyacinth-associated microbes in the bioremediation potentials, suggesting the need for the bioprospecting of these lesser-studied microbes. Overall, our study summarizes the prospects and utilities of the metagenomic approach and proposes the need to employ it for efficient bioremediation.

Nutrient conditions influence allelopathic capabilities of Ludwigia adscendens and other tropical macrophytes against Microcystis aeruginosa

Abstract Macrophytes may release allelochemicals that suppress competing phytoplankton, although it is unclear how their effectiveness could be influenced by environmental nutrient conditions. To approach this, we conducted a series of bioassays against the bloom‐forming cyanobacterium Microcystis aeruginosa using extracts and exudates from potentially allelopathic macrophytes under varying nutrient conditions. We screened six different tropical macrophytes and identified antialgal effects in both extracts and exudates of Ludwigia adscendens, Persicaria barbata, Pontederia crassipes and Vallisneria spiralis. Growth assays indicated that extract inhibitory effectiveness decreased as nutrient concentration increased from 5% to 50% strength. Focusing on the potent antialgal extract of L. adscendens, we determined that its inhibitory effects were enhanced by specifically reducing the availability of either micronutrient or bicarbonate availability, indicating a role of these nutrients in protecting algal cells from allelochemicals. Bioactivity‐guided fractionation and ultra‐performance liquid chromatography – mass spectrometry analyses of L. adscendens extract indicated that ellagitannins were the major constituent of bioactive extract fractions, suggesting an antialgal mechanism common to other tannic compounds. Novel allelopathic alkaloids and terpenoid compounds also were described, although their mechanisms of action are unknown. Our findings provide evidence that the availability of carbon and micronutrients to cyanobacteria could influence the effects of macrophyte allelochemicals. This interaction between the nutrient environment and allelochemical sensitivity of cyanobacteria can be substantial, and studies or applications involving allelopathic interactions between macrophytes and phytoplankton should consider this.

Graphitic Carbon Nitride (g-C<sub>3</sub>N<sub>4</sub>) Microrods and Nanosheets Photocatalysts Immobilized on Water Hyacinth Cellulose Sponge for Photodegradation

In this research, the researchers successfully fabricated photocatalysts hybrid materials using g-C3N4 microrods and g-C3N4 nanosheets, which were coated on water hyacinth cellulose sponges. The optical properties of the photocatalysts hybrid materials, specifically the g-C3N4 microrods and g-C3N4 nanosheets, were analyzed using a UV-vis spectrometer. The morphology of the g-C3N4 microrods and g-C3N4 nanosheets photocatalysts was examined using different procedures, including FTIR (Fourier-transform infrared spectroscopy), XRD (X-ray diffraction), and TEM (transmission electron microscopy). The results obtained from the study indicate that g-C3N4 microrods exhibited a higher level of crystallinity or orderliness in terms of intramolecular orientation compared to g-C3N4 nanosheets. This suggests that the microrods possessed a more organized arrangement of atoms within the material structure. Furthermore, the energy bandgap values, as determined from the study, were found to be 2.25 eV for the microrods and 2.75 eV for the nanosheets. As part of this project, the photocatalysts, namely g-C3N4 microrods and g-C3N4 nanosheets, were utilized as coating materials for water hyacinth-synthesized cellulose sponges. This process led to the formation of hybrid materials known as g-C3N4 MCS (Microrods Cellulose Sponge) and g-C3N4 NCS (Nanosheets Cellulose Sponge). The efficiency and reaction rate of MB removal were then studied with various models such as First order reaction, Second order reaction, Pseudo first order reaction, Pseudo second order reaction and Elovich model. The results obtained from the research project indicated that the g-C3N4 NCS hybrid material exhibited a notably higher rate of organic degradation compared to the g-C3N4 MCS hybrid material. In conclusion, this research project successfully achieved the fabrication and characterization of a photocatalysts hybrid material using cellulose sponge from water hyacinth. The material demonstrated excellent performance as an absorbent and degradation agent for organic pollutants in water, highlighting its potential for practical applications in water treatment and environmental remediation.

Water Hyacinth (Eichhornia crassipes) As a Possible Alternative Energy Source: A Case Study for INSEE Cement Manufacturing Plant in Puttalam, Sri Lanka

Cement manufacturing is typically energy-intensive process and currently using alternative fuels partially or totally to replace fossil fuels to reduce the energy and environmental costs. Biomass is one of the main alternative fuel utilized by the cement industry with the potential to replace up to 20% of total energy demand. Water hyacinth (WH) is a problematic invasive alien species in aquatic ecosystems of all climatic zones in Sri Lanka. Because of it is non-edible, rapid growth, and freely available in larger quantities, WH has the potential to be used as biomass energy. Several countries have been studied for WH as feedstock for bioenergy production while physical and chemical composition of WH biomass has been tested by many researchers. However, biomass physiochemical properties may be varied by different place and conditions and there is no significant study for industrial application of WH biomass to burn in cement plant kiln as alternative energy source. Thus, this study aimed to elucidate the potential of WH biomass as an alternative energy source for the INSEE cement plant in Puttalam. The study was conducted in three selected reservoirs namely, Tabbowa reservoir (TR), Murukkuwatawana reservoir (MR), and Nawadankulama reservoir (NR) located in Puttalam district Northwestern province of Sri Lanka. The quantity of fresh and dry WH biomass was estimated with the WH covered area and fresh and dry weights of WH in unit area.WH covered area of in each reservoir during 2020 and 2021 was digitized directly in Google earth satellite images using Google Earth Pro software with help of visual interpretation techniques. WH biomass per unit area were measured by the subjective sampling method. WH samples from each reservoir were collected for analyzing biomass, and to determine the fuel characteristics such as net calorific value (NCV), Chlorine and Sulfur content, moisture, volatile matter, fixed carbon, and ash content. According to the results, the fresh WH biomass was recorded as 692.62, 389.85, 23.58 tons in 2020 and 3570.82, 584.53, 33.31 tons in 2021 in the TR, MR, and NR respectively, while the dry WH biomass was recorded as 41.65, 24.65, 1.31 tons in 2020 and 214.74, 36.96, 1.85 tons in 2021 in the TR, MR, and NR respectively. NCV of the WH composite sample was 12.02 MJ/kg. Moisture content, ash content, chlorine and sulfur content were recorded as 13.56%, 10.95%, 1.06%, and 0.14% respectively. Except for chlorine content, other parameters agreed with the acceptable limits for using WH as an alternative energy source for cement industry. To replace 1 ton of coal, 2.2 tons of dry WH were required from 35 tons of fresh WH biomass while to produce 1 ton of clinker, 0.32 tons of dry WH were required from 5.2 tons of fresh WH biomass. Since relatively large quantities are freely available and with high volatile content and calorific value, WH is suitable as an alternative energy source for cement industry. However, economic feasibility should be studied prior to the commercial application.
 Keywords: Alternative fuel, Biomass, Water hyacinth, Calorific value

Eichhornia crassipes Leaves as a Waste-derived Bio-Sorbent to Remove Organics and Nutrients from Rice Mill Wastewater

The increased rate of population growth resulted in the increased number of rice mill industries to fulfill the demand for rice. The rice mill wastewater contains a high load of organics and nutrients. Therefore, the direct discharge of wastewater into the environment may degrade the quality of the environment as well as causes adverse effects on human health. Among various methods to treat waste effluent, bio-sorption is a cheap and environmentally sound approach. Eichhornia crassipes is a noxious weed that spreads rapidly. Most of the tanks in Vavuniya are polluted by E. crassipes and it needs a sustainable solution. This study uses the leaves of E. crassipes to produce waste-derived bio-sorbent to treat rice mill wastewater. The wastewater was collected from one of the rice mills in the Vavuniya town area. The adsorption isotherm and adsorption kinetics experiments were conducted to find out the removal efficiencies of COD, nitrate, and phosphate from wastewater. The effect of the dosage of bio-sorbent (1-6 g/L) and the contact time (30-180 min) with the wastewater was studied to determine the optimum dosage and optimum contact time. The bio-sorbent showed maximum removal efficiencies of COD (54.5%), nitrates (58.1%), and phosphates (29.5%) at the optimum dosage of 4 g/L at 120 min. Based on the t-test, E. crassipes leaves significantly reduce COD, nitrate, and phosphate (p-value<0.05). However, COD and nitrate showed higher removal rates than phosphate. Further, long-term column studies should be conducted to apply the above technique in wastewater treatment plants in treating the rice mill wastewater in the real world. This study emphasizes that E. crassipes leaves have the potential to remove contaminants from wastewater as well as this would also help to minimize the spread of the weed to safeguard the environment. 
 Keywords: Eichhornia crassipes, Bio-sorption, Vavuniya tank, Water quality 

Management of Free-floating Aquatic Weeds by Making Compost and Testing its Efficacy against Root-knot Nematode on Tomato

Aquatic weeds are one of the prime pollution causing agents in fresh water bodies of Sri Lanka. In Sri Lanka, free-floating aquatic weeds such as Salvinia molesta, Eichhornia crassipes, Azolla spp and Pistia stratiotes are proliferating quickly and invading rapidly to new water bodies where threatening biodiversity by impeding light penetration and altering BOD and COD of the waterbody. This research was aimed to manage the aquatic weeds by composting and testing its efficacy on root-knot nematodes. Aquatic weeds were collected, mixed with fresh cow dung in 1:1 ratio and allowed for decomposition for 21 days. The recommended dose of prepared different compost was applied to tomato along with garden compost as control. The experiment was conducted in Complete Randomized Design (CRD) with four replicates. The data on nutritional qualities of the compost, plant growth parameters, and gall index were recorded. The data were subjected to ANOVA using SAS 9.1 and Tukey's HSD multiple comparison test was used to determine the best treatment combination at P<0.05. Total Nitrogen (N) content of composts were ranging from 1.42% to 5.6%. The highest significant N value of 5.6% was recorded in the Azolla spp based compost whereas the lowest N value of 1.42% was recorded in control. The highest total Phosphorus (P) content of 3.47% was observed in P. stratiotes based plant sample, whereas the lowest P value of 1.32% was recorded in the E. crassipes based compost. The total Potassium (K) content of this plant sample ranging from 1.3% to 24.4%. The highest K value of 24.4% was recorded in P. stratiotes based compost. The lowest K content of 1.3% was observed in control. Significantly higher shoot height (37.57 cm, 36.53), root length (18.75 cm and 17.5 cm), lower gall index (3.5,1.0), lower goal length (1.5 mm and 1.2 mm) and lower goal diameter (0.95 mm and 0.8 mm) were recorded in the application of S. molesta and Azolla spp based compost, respectively (P<0.05). Considering superiority of N, P and K level, and nematode suppressing efficacy, S. molesta and Azolla spp. based composts are superior than other composts. Therefore, findings conclude that the compost made from aquatic weeds are good source of plant nutrition, and can be substitute to chemical nematicieds to manage the nematodes in organic agriculture. Extensive field studies are needed for recommendation 
 Keywords: Aquatic weeds, Azolla spp., Compost, Root-knot Nematode

Habitat Preference of Lesser Whistling Ducks (Dendrocygna javanica) in Selected Wetlands within Colombo Ramsar Wetland City

Lesser Whistling Ducks (LWD) (Dendrocygna javanica) mostly occur in flocks and inhabit lakes, ponds and marshes within freshwater wetlands. They feed mainly on plants taken from water (seed, shoots, tuber and leaves), vertebrates (fishes) and invertebrates (mollusks and worms). In this study, habitat preference of LWD in five selected wetlands in Colombo Ramsar Wetland City (CRWC); Beddagana Wetland Park (BWP), Diyasaru Park (DP), Heen Ela Marsh (HEM), Thalangama Marsh (TM) and Kimbulawala Wetland (KW) was studied from May 2021 to April 2022 as wetlands in urban areas act as the last resort for many resident and migratory bird species and play a major role in the assemblage and conservation of water birds. Habitats present in the selected wetlands were categorized as open water body, floating vegetation, trees, grassland, paddy field, shrubs, bare land. Percentage cover of each habitat type at each sampling site were estimated using quadrat method. LWD were surveyed using line transects of 100m in length, laid in each selected study site to cover representative habitats and observations were made up to 30m towards either side of each transect. Sampling was done in three time slots of the day, morning, mid-day and evening. Floating vegetation, open water body and grassland were the preferred habitat types of D. javanica in BWP, DP, HEM and TM. LWD were not recorded in KW. Floating vegetation (54.97%) was the most preferred habitat by LWD in each study site followed by open water body (24.70%) and grassland (15.82%) habitat types. Eicchornia crassipes (Common water hyacinth) and Salvinia molesta (Giant salvinia) were their most preferred floating vegetation type. Higher abundance of LWD was recorded in TM (83.22%) followed by DP (9.17%), BWP (4.16%) and HEM (3.45%). TM which had higher abundance of LWD had higher floating vegetation coverage (28%) and was rich with E. crassipes and S. molesta. Present study revealed that, LWD mostly used E. crassipes and S. molesta as their main foraging and resting sites. Management of invasive alien species have been undertaken in Colombo wetlands and as E. crassipes and S. molesta are alien species they are currently being removed. Therefore, outright removal of E. crassipes and S. molesta may not be suitable and a monitored removal program that will conserve this habitat type should be implemented in order to conserve the habitats preferred by LWD in CRWC. 
 Keywords: Lesser whistling ducks, Wetlands, Habitat preference 

Efficacy of Flavonoids from Selected Plants in Controlling Callosobruchus maculatus on Cowpea Seeds (Vigna unguiculata)

Phytochemicals act extensive active against stored pest have long been exciting alternative to synthetic pesticides besides, evidenced flavonoids that among the plant constitute a rich source of bio-active chemical which are much safe with eco-friendly that applicable to protect insects. The experiment especially aims to investigating influence of flavonoids from the selected plants leaves such as Moringa oleifera (moringa), Lantenna camera (nayunni), Justicia adhatoda (adhathodai), Pepper nigrum (pepper), Annona reticulate (annona), Eichhornia crassipes (water hayasinth), Eucalyptus globules (eucalyptus), Citrus aurantiifolia (lime), Azadiracta indica (neem), Achyranthes aspera (nayuruvi), Ocimum tenuiflorium (thulsi), Cymbopogan citratus (lemon grass). Capsicum annuum (chilli), piper longum (thipilli) and Vitex trifolia (nochchi), located in Eastern Regions of Sri Lanka against cowpea weevil, Callasobruchus maculatus on stored cowpea seeds (V. unguiculata) during storage. 10 g of each leaf dry powder separately extracted with 100 mL of 80% aqueous methanol at room temperature and filtrates were transferred in to 100 mL conical flask and evaporated into dryness to over a water bath and used standard scientific method to obtained flavonoids. 200 cowpea seeds thoroughly mixed with 2 mg flavonoids and replicated thrice for one treatment. As similar manner other treatments and untreated control were designed and introduce with 5 pairs of newly emerged cowpea weevil, C. maculatus in 100 mL capacity plastic bottle with arranged in Complete Randomized Design (CRD) and started to monitor from 1st day after treatment (DAT). Adult mortality and number of eggs laid on seeds of each treatment were recorded daily until 6th DAT and retained for further 30 days to assess new progeny production of the weevil
 
 C. Flavonoids from J. adhatoda and P. nigrum shown excellent constituent to kill all the adult C. maculatus within 6 days followed by O. tenuiflorium (80%) and it was significantly (p≤0.05) as par with E. globules (72.6%) and A. indica (74%). Similarly, the flavonoids from these above mentioned leaves dry powders except P.nigrum significantly active against fecundity of an adult which shown J. adhatoda (6.3 egg/female), C .aurantiifolia (7 eggs/female) and O. tenuiflorium (7 eggs/female), however J. adhatoda totally affect the development of F1 new progeny production. According to the observations the differences were not statistically significant about the fecundity between the flavonoids from P. nigraum, A.indica and C.annuum. L.camera, E. crassipes and C. citratus did not show any significant effect on adult mortality, fecundity, new progenies as well as obtained much damage seeds next to control and obtained unsatisfactory results as untreated control while, M. oleifera, A. reticulate, V. trifolia and C. annuum obtained moderately against adulticidal activities of C. maculatus on cowpea seeds during the storage until 30 days. However, J. adhatoda proven its efficacy on cowpea seeds to control C. maculatus by highly effective to suppressing new progeny production and led without any damage in the seeds during the storage.
 
  
 Keywords: Flavonoid, Adult, Mortality, Callosobruchus maculatus, Justicia adhatoda

ZnO nanomaterials with enhanced antimicrobial activity obtained by Eichhornia crassipes aqueous extract‐mediated synthesis

AbstractBACKGROUNDZinc oxide nanoparticles (ZnO NPs) were obtained through precipitation synthesis, using aqueous water hyacinth leaf extract (Eichhornia crassipes) under alkaline conditions. The effect of the extract on the physicochemical and antimicrobial properties of the ZnO was evaluated starting from concentrated extract (labeled as E100) and performing two dilutions of this concentrated extract at 50% and 25% in water (E50, and E25).RESULTSThe FTIR spectra revealed strong peaks at ≈3440 cm−1, corresponding to vibrations from OH stretching, and medium‐intense peaks at 1384 and 1327 cm−1, assigned to CC, COOH and COC vibrations, which are related to the presence of the extract; a weak band at 884 cm−1 and a broad band in the region below 600 cm−1 indicate the presence of ZnO. The hydrodynamic size of the ZnOE100, ZnOE50 and ZnOE25 samples were 202, 244 and 313 nm, respectively. No significant variations on the Eg value were observed. Field emission scanning electron microscopy images showed that the ZnO NPs have triangular‐like shapes and agglomeration of the NPs synthesized for the ZnOE25 sample. The minimum inhibitory concentration (MIC) of the ZnO NPs showed no significant effects related to the concentration the plant extract used.CONCLUSIONSVariations in particle size and zeta potential can be introduced in ZnO by varying the content of the extract; the presence of organic groups from the extract, along with a positive zeta potential value, can promote the bactericide effect of ZnO nanomaterials prepared by bio‐assisted synthesis. © 2024 Society of Chemical Industry (SCI).

Overview Metode Fitoremediasi Dalam Pengelolaan air Tercemar Timbal (Pb)

Wastewater originating from industry varies greatly depending on the type of industry. Industrial wastewater usually contains many toxic and dangerous chemical compounds (B3) and contains heavy metals. Heavy metals are pollutants that have dangerous effects because they cannot be broken down biologically and stable. Heavy metal elements can be distributed on the earth's surface in water, soil and air. Heavy metal waste pollution containing lead (Pb) is a problem for current environmental conditions. Heavy metals are found in almost all types of industrial waste. The increasing number of industries will cause increased pollution of water sources originating from industrial waste. . Therefore, effective and efficient methods are needed to manage lead-contaminated water. Methods that are easy to apply, low cost and environmentally friendly are highly desirable for managing lead-contaminated water so that the concept of good mining practice can be applied to sustainable development. The most efficient and effective method applied for mining waste management is the phytoremediation method. The results of the research state that several plants have a significant and efficient effect in helping the absorption of the metal lead (Pb) contained in water. Great Duckweed (Spirodela Polyrhiza) and Water Hyacinth (Eichhornia crassipes) are plants that are suitable for implementing phytoremediation methods in managing water contaminated with lead (Pb).

Plastic does not simply flow into the sea: River transport dynamics affected by tides and floating plants

Plastic pollution is ubiquitous in aquatic environments worldwide. Rivers connect terrestrial and marine ecosystems, playing a key role in the transport of land-based plastic waste towards the sea. Emerging research suggests that in estuaries and tidal rivers, tidal dynamics play a significant role in plastic transport and retention dynamics. To date, observations in these systems have been limited, and plastic transport dynamics during single tidal cycles remain poorly understood. Here, we investigated plastic transport, trapping, and re-mobilization of macroplastics (> 0.5 cm) in the Saigon River, focusing on short-term dynamics of individual tidal cycles. We used GPS trackers, released at different stages of the tidal cycle (ebb, flood, neap, spring). Plastic items demonstrated dynamic and intermittent transport behavior. Items spent almost half of the time (49%) temporarily stopped, mainly due to their entrapment in vegetation, infrastructure, or deposition on riverbanks. Items were almost always re-mobilized within 10 h (85%), leading to successive phases of stopping and transport. Tidal dynamics also resulted in bidirectional transport of plastic items, with median daily total transport distance within the 40 km study reach (8.9 km day−1) over four times larger than the median daily net distance (2.0 km day−1). The median retention time of plastic items within the reach was 21 days (mean = 202 days). In total, 81% of the retrieved items were trapped within water hyacinths, emphasizing the important role of floating vegetation on river plastic transport dynamics. With this paper, we aim to provide data-driven insights into macroplastic transport and retention dynamics in a tropical tidal river. These are crucial in the design of effective intervention and monitoring strategies, and estimating net plastic emission from rivers into the sea.

Persulfate oxidation of norfloxacin by cobalt doped water hyacinth biochar composite: The key role of cobalt and singlet oxygen

The decay of active components and difficulty in separation and recovery are two major challenges for the use of biochar as a catalyst in the activation of persulfate (PS). In this study, cobalt loaded water hyacinth biochar (Co-BC) has been prepared and utilized in activation of PS for norfloxacin (NOR) degradation. Characterization results confirmed that cobalt mainly existed in the form of Co0 and Co3O4. The specific surface area of Co-BC was 349.00 m2/g, which was roughly 10 times greater than that of biochar (BC). NOR degradation experiment results showed that the Co-BC/PS system was able to remove 97.66 % of the NOR, which was nearly 1.57 times more efficient than that of BC/PS system. Electron paramagnetic resonance and free radical scavenging experiments illustrated that singlet oxygen(1O2) played the key role for NOR removal. The NOR removal mechanism revealed that Co played a crucial role for the activation of PS. Thus, Co-BC can serve as an eco-friendly catalyst for activating PS to efficiently eliminate antibiotics from water.

Investigation on Environmentally Polluted Water Hyacinth with Banana Fibre Reinforced Composite Absorption Properties

A study of hyacinth plant fibres derived from aquatic wastewater aimed at developing lightweight, durable synthetic materials reinforced with banana fibres. The availability and sustainability of banana fibre make it one of the best choices for natural fibres. Traditional materials are extremely heavy, heavy, and expensive when compared to banana fiber materials. Their strength, lightness, and affordability make them ideal for this purpose. Recently, natural fibres have gained attention from scientists as reinforcement materials for polymeric composites and technical applications. There are many advantages to using natural fibres, including continuous supply, easier handling, and biodegradability. Particle boards on the market have a lower hardness strength than banana fibre composite boards. ASTM standards determine parameters such as hardness strength and absorption. According to their hardness strength, banana composites have hardness values of 95 shore D. The absorption levels of banana composites can be increased by 15 to 30%, depending on reinforcement. Compared to the other samples, 30% of the composite samples were able to achieve the high performance. The use of metal as a wood alternative for automobile bodies has been found to be promising in a number of applications.

Physical Properties of Water Hyacinth, Polyester, and Cotton Blended Spun Yarn: A Blend Ratio Study

ABSTRACT The goal of the study is to investigate the ideal mix ratio for yarn spinning in the production of industrial textiles, taking into account the physical properties of water-hyacinth-based fabric and yarn. Cotton, polyester, and water hyacinth had a weft yarn mix ratio of 20:25:55. The completed piece demonstrates the unique dark colour and fibre properties of the Water Hyacinth yarn. There are two distinct construction types in the cloth. In plain weaving, ply yarn is used to create the woven structure by reinforcing the weft strand structure. The unique twill fabric was developed to take the place of several natural fabric types that are now available on the market. The warp-to-weft thread ratio is tightly displayed.

Pontederia crassipes invasiveness on Jeju island is linked to a decline in water pH and climate change-driven overwintering

Freshwater ecosystems are vulnerable to the invasion of exotic aquatic plant species because of the great likelihood of the introduction of exotic species, and the lack of barriers that block introduced species. Water hyacinth, Pontederia crassipes Mart., is one of the world’s most invasive alien plant species damaging freshwater ecosystems worldwide. Here, we monitored the water hyacinth population on Jeju island, Korea, to assess current invasion risks. Furthermore, we investigated how water hyacinth affects water pH because pH is an important determinant of the distribution of other aquatic plants, and thus a good indicator of aquatic ecosystem health. Water containing water hyacinth had a pH of 5.3, while that with water hyacinth and soil had a pH of 4.8 72 hours after the start of the experiment. Water hyacinth extracts contained shikimic acid, stearic acid, and palmitic acid, which are possible compounds that caused a decline in water pH. Water hyacinth also inhibited the growth of the aquatic plant species, Spirodela polyrhiza and Lemna perpusilla. These results imply that invasion of water hyacinth adversely impacts the abiotic and biotic characteristics of aquatic ecosystems. Moreover, monitoring the water hyacinth population suggests that this invasive aquatic plant overwinters on Jeju island. Therefore, regular monitoring and subsequent control of water hyacinth population can prevent its expansion in the aquatic habitats of Jeju island and the southern region of the Korean peninsula.

Effect and Mechanism of Bicarbonate Ion on Lead Absorption in Pontederia crassipes from Karst Water

Bicarbonate ions (HCO3−) are abundant in karst water with poor lead (Pb) utilization and biodegradation. This study aimed to investigate the mechanism of HCO3− on the Pb removal efficiency and uptake ability of Pontederia crassipes (a widespread hydrophyte in the karst area) from karst water. The Pb concentration, Pontederia crassipes morphology, and functional group were detected. As the HCO3− molarity in karst water increased (3, 4, and 5 mmol/L), the removal of Pb increased (85.31%, 93.28%, and 95.16%), whereas the bioconcentration amount of Pb decreased (573, 501, and 301 mg/kg), mainly due to the insoluble PbCO3 and Pb (OH)2. The Pb bioconcentration factor was the highest (15,564) at 4 mmol/L HCO3− due to the maximum strength of cation exchange and cell wall protein C=O. High HCO3− molarities changed the variety of positive ions of cation exchange (HCO3− ≤ 4 mmol/L: Na, K, and Mg; HCO3− > 4 mmol/L: Mg and K), and relieved the breaking of roots, stomatal closure, and vascular system shrinking. Moreover, high HCO3− molarities diminished the C≡C oxidation, enlarged the displacement of SO42− and C-O, and stimulated the methyl transfer reaction and the bonding between -CH3 and Pb.

Production and characterization of polyhydroxybutyrate bioplastic precursor from Parageobacillus toebii using low-cost substrates and its potential antiviral activity

There is an increasing desire for bioplastics produced from renewable resources as an alternative to their petrochemical counterparts. These biopolymers have long-unnoticed antiviral properties. This study aimed to produce and characterize bioplastics by Parageobacillus toebii using low-cost substrates and determine their antiviral activity against coxsackievirus B4. Seven low-cost substrates (bagasse, water hyacinth, rice straw, rice water, sesame husks, molasses, and corn syrup) were compared with glucose for bioplastic precursor production. The highest bioplastic produced was from water hyacinth and glucose, followed by molasses, rice straw, rice water, sesame husks, and bagasse. Water hyacinth and glucose media were further optimized to increase the bioplastic precursor yield. The optimization of the media leads to increases in bioplastic precursor yields of 1.8-fold (3.456 g/L) and 1.496-fold (2.768 g/L), respectively. These bioplastics were further characterized by thermogravimetric analysis (TGA), Fourier-transformed infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1H NMR), and gas chromatography–mass spectrometry (GC–MS). They are thermostable, and their characterizations confirm the presence of polyhydroxybutyrate. The antiviral assay showed reasonable antiviral effects for bioplastics from water hyacinth (80.33 %) and glucose (55.47 %) media at 250 μg/mL maximum non-toxic concentrations (MNTC). The present investigation demonstrates a low-cost model for producing polyhydroxybutyrate bioplastic precursor for antiviral applications.