Search Results (4)

This study introduces a gamma pretreatment of water hyacinth powder for activated carbon (AC) production with improved electrochemical properties for supercapacitor applications. The structural and morphological changes of post-irradiation were meticulously analyzed using scanning electron microscopy (SEM), Raman spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller (BET) analysis, and X-ray photoelectron spectroscopy (XPS). The pretreatment significantly modifies the pore structure and reduces the particle size of the resulting activated carbon (WHAC). Nitrogen adsorption-desorption isotherms indicated a substantial increase in micropore volume with escalating doses of gamma irradiation. Electrochemically, the activated carbon produced from pretreated WH at 100 kGy exhibited a marked increase in specific capacitance, reaching 257.82 F g⁻¹, a notable improvement over the 95.35 F g⁻¹ of its untreated counterpart, while maintaining 99.40% capacitance after 7000 cycles. These findings suggest that gamma-pretreated biomasses are promising precursors for fabricating high-performance supercapacitor electrodes, offering a viable and environmentally friendly alternative for energy storage technology development. Full article

Macrophytes have the potential to withstand pollutant-induced stress and can be used to clean contaminated water using phyto-extraction, phyto-degradation, phyto-filtration, phyto-stimulation, and phyto-volatilization technique(s). Phytoremediation through constructed wetlands (CWs) for eliminating inorganic and organic pollutants from household sewage and wastewater has attracted scientific attention. CWs are artificially engineered treatment systems that utilize natural cycles or processes involving soils, wetland vegetation, and plant and soil-associated microbial assemblages to remediate contaminated water and improve its quality. Herein, we present a detailed assessment of contaminant removal effectiveness in different CW systems, i.e., free-water surface or surface-flow constructed wetlands (FWSCWs/SFCWs), subsurface-flow constructed wetlands (SSFCWs), and hybrid constructed wetlands (HCWs). Several wetland floral species have been reported as potential phytoremediators, effectively reducing aquatic contamination through biodegrading, biotransforming, and bioaccumulating contaminants. Water hyacinth (Pontederia crassipes) is one of the most resistant macrophytes, capable of tolerating high nitrate (NO₃⁻) and phosphate (PO₄²⁻) concentrations. Other aquatic weeds also effectively alleviate biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS), and pathogen levels and ameliorate the impact of different ionic forms of nitrogen (N), phosphorus (P), and trace elements (TEs). The review primarily focuses on using hydrophyte(s)-microbe(s) associations in different CWs as an essential phytoremediation tool for sustainable management of freshwater ecosystems, ecorestoration, and prospective resource recovery, favoring a circular bioeconomy (CBE). Full article

Solar-driven steam generation for desalination is a facile, sustainable, and energy-saving approach to produce clean freshwater. However, the complicated fabrication process, high cost, potential environmental impact, and salt crystallization of conventional evaporators limit their large-scale application. Herein, we present a sustainable Janus evaporator based on a biopolymer sponge from the water hyacinth petiole (WHP) for high-performance solar steam generation. The freeze-dried WHP maintained its original porous structure and aligned channels well, and therefore holds the capability for rapid water transport due to strong capillary action. The WHP coated with carbon nanotubes/ethyl cellulose paste on its surface (WHP-C) gains a good photothermal property, thus achieving an efficient solar steam generation with a rate of 1.50 kg m⁻² h⁻¹ under 1 sun irradiation. Moreover, the WHP-C after hydrophobic modification by fluorocarbon (WHP-CH) is endowed with high water repellency and exhibits good salt resistance during long-term solar desalination. Additionally, we demonstrate that a stable wet surface that enables efficient water supply and vapor escape is also significant to the successive desalination of a solar evaporator. Our work provides new insights into the high-value utilization of biomass waste, i.e., water hyacinth, and the development of sustainable interfacial solar evaporators for the environmentally friendly production of freshwater. Full article

The aim of this research was to determine whether water hyacinth can be used to remove heavy metals, such as cadmium, arsenic, lead, zinc, and copper, from industrial wastewater. Investigations of the pollution removal or prevention potential of aquatic macrophytes, such as heavy metal bio-indicators in aquatic habitats, can prove to be advanced field studies. Water hyacinth is one of the aquatic plant species that has been effectively utilized for the treatment of wastewater. It is extremely effective in removing stains, suspended solids, BOD, organic matter, and heavy metals. This research focused on the use of water hyacinth to treat wastewater from heavy metals. Water hyacinths can grow in sewage, absorbing and digesting contaminants and transforming sewage effluents into comparatively clean water in the process. As a result, the plants have the potential to be used as natural water purification systems at a fraction of the cost of a standard sewage treatment facility. The experiment was performed using healthy, young, and acclimatized water hyacinths. Containment water with a cadmium concentration of 0.5 mg/L, arsenic concentration of 0.5 mg/L, lead concentration of 2 mg/L, zinc concentration of 5 mg/L, and copper concentration of 5 mg/L was added to five different polyethylene pots with 100 g of water hyacinth in each pot. After 30 days, the removal efficiency for heavy metals (Cd, As, Pb, Zn, and Cu) reached 59–92%, and the results were within the permitted limits according to the National Technical Regulation on Industrial Wastewater in Vietnam. Based on this information, it is possible to deduce that water hyacinth can be utilized to remove cadmium, arsenic, lead, zinc, and copper from industrial wastewater effluents efficiently. Full article