Search Results (7)

Water pollution by persistent organic and inorganic contaminants constitutes a significant problem for ecosystems and public health. Organic substances such as dyes, pharmaceutical residues, pesticides, and phenolic compounds are increasingly detected in water due to industrial and agricultural activities. Alongside these, toxic heavy metals contribute to the complexity of water treatment challenges. Conventional remediation methods often fall short due to high operational costs or limited efficiency. In this context, photocatalysis has emerged as a promising approach for pollutant degradation in water under light irradiation. In this sense, covalent organic frameworks (COFs), a class of porous, crystalline materials formed by the covalent linkage of organic units, offer great advantages as photocatalysts. Their tunable electronic properties, structural diversity, and high stability under aqueous conditions make them ideal for visible light-driven processes. This review explores the structural features that govern the photocatalytic activity of COFs, including conjugation, bandgap modulation, and donor–acceptor structures. Mechanistic insights into photocatalytic degradation are also discussed. Finally, examples of pre-designed COFs are presented with their application in the photodegradation of water pollutants, and their main reactive oxygen species (ROS) involved in the photodegradation mechanism. Overall, this review aims to provide a foundation for the rational design of COFs in advanced water treatment technologies. Full article

Addressing the critical issue of water pollution, this review article emphasizes the need to remove hazardous dyes and phenolic compounds from wastewater. These pollutants pose severe risks due to their toxic, mutagenic, and carcinogenic properties. The study explores various techniques for the remediation of organic contaminants from wastewater, including an enzymatic approach. A significant challenge in enzymatic wastewater treatment is the loss of enzyme activity and difficulty in recovery post-treatment. To mitigate these issues, this review examines the strategy of immobilizing enzymes on newly developed nanostructured materials like graphene, carbon nanotubes (CNTs), and metal–organic frameworks (MOFs). These materials offer high surface areas, excellent porosity, and ample anchoring sites for effective enzyme immobilization. The review evaluates recent research on enzyme immobilization on these supports and their applications in biocatalytic nanoparticles. It also analyzes the impact of operational factors (e.g., time, pH, and temperature) on dye and phenolic compound removal from wastewater using these enzymes. Despite promising outcomes, this review acknowledges the challenges for large-scale implementation and offers recommendations for future research to tackle these obstacles. This review concludes by suggesting that enzyme immobilization on these emerging materials could present a sustainable, environmentally friendly solution to the escalating water pollution crisis. Full article

Phenolic chemicals are poisonous and have long-term impacts on humans and animals. Even in low quantities, as carcinogens, they destroy red blood cells and the liver. These biological waste products pollute groundwater. Thus, removing these organic chemicals to meet discharge limits is difficult. Electrochemical oxidation, redox reactions, membrane separation, and photocatalytic degradation help remove phenolic chemicals from water. Recently, phenolic chemicals have been shown to be removed via adsorption and photocatalysis employing carbon materials and clays. Due to their unique chemical and physical properties, nanometric materials are crucial to these processes. These substances’ structures, classification, entry points, and reactivity or interaction with other aquatic components have been extensively studied. Phenolic substances can be removed from the water before usage. This has led to the development of water treatment technologies and methods like activated carbon adsorption, solvent extraction, the electro-Fenton method, membrane-based separation method, photocatalysis, and others that have been shown to successfully remove phenolic compounds from water. Activated carbon is the most promising adsorbent for numerous contaminants (dyes, metals, etc.). However, low-cost agricultural materials are typically used to switch to more environmentally friendly ones. This study uses low-cost, eco-friendly adsorbents to remediate biomedical effluents. Pyrolysis of potato peels (waste) from a restaurant produced carbon samples. Absorption–desorption experiments examined pH, temperature, starting drug concentration, contact time, and regeneration ability. Full article

Rapid urban and industrial sectors generate massive amounts of wastewater, creating severe ecological disruption and harming living organisms. The number of harmful pollutants such as dyes, heavy metals, antibiotics, phenolic compounds, and volatile and several organic chemicals discharged into aquatic systems varies depending on the effluent composition of various sectors. MXene-based composites with unique characteristics were spotlighted as newly developed nanomaterials specifically for environmental-related applications. Therefore, this review broadly discusses the properties, basic principles of MXene, and synthesis routes for developing different MXene-based nanomaterials. The most current strategies on the energy and environmental applications of MXene-based nanomaterials, particularly in photocatalysis, adsorption, and water splitting, were deeply explored for the remediation of different pollutants and hydrogen (H₂) evolution from wastewater. The detailed mechanism for H₂ evolution and the remediation of industrial pollutants via photocatalysis and adsorption processes was elaborated. The multi-roles of MXene-based nanomaterials with their regeneration possibilities were emphasized. Several essential aspects, including the economic, toxicity and ecological power of MXene-based nanomaterials, were also discussed regarding their opportunity for industrialization. Finally, the perspectives and challenges behind newly developed MXene and MXene-based nanomaterials for environmental pollution were reviewed. Full article

Juglans regia L., walnut, is a large, long-living tree, cultivated in temperate climates around the world. It is highly appreciated for its nutritional kernels and high-quality timber. Its barks, leaves, and husk are used as dyes and in folk medicine as herbal remedies for several diseases. From a biological and chemical standpoint, relatively little is known about the male flowers of the tree. Therefore, the aim of the study was to evaluate the phenolic profile as well as in vitro antioxidant, antimicrobial, and antiproliferative activity of male Juglans regia L. flowers. Phenolic content was determined by UPLC/PDA/MS/MS analyses; antioxidant activity was assessed by five different methods; antimicrobial activity was evaluated against the six most common pathogenic strains of Gram-positive and Gram-negative bacteria, and antiproliferative properties were assessed against six cell lines. Most of the analyses carried out in this study were performed for the first time for this raw material. J. regia flower extract was characterized by a strong ability to scavenge DPPH˙ free radicals, hydroxyl radicals, and chelating metal ions. Among the examined bacterial strains and neoplastic lines, the strongest antimicrobial activity was shown against S. aureus, L. monocytogenes, and B. cereus, and cytotoxic activity against breast cancer, glioblastoma, and astrocytoma cells. Male J. regia flowers have also been found to be a rich source of phenolic compounds. The content of polyphenols in the extract was 4369.73 mg/100 g d.w., and 24 compounds from the group of flavonoids, phenolic acids, and juglunosides were identified. Additionally, a strong correlation between the content of polyphenols and the antioxidant capacity and cytotoxic activity was observed. This is why the tested J. regia flowers are an excellent source of effective natural antioxidant, antibacterial, and chemopreventive compounds that have potential to be used in the pharmaceutical or food industries. Full article

Parthenium hysterophorus is an invasive weed species that competes aggressively with other plants and is also allelopathic. It poses a significant risk to human health, livestock, the environment, soil, and agriculture. However, given some clinical studies, its potential for antidiabetic, antioxidant, antitumor, herbicidal, pesticidal, and antimalarial therapies should be researched further in attempts to discover more relevant applications. It can be used as a nutrient-dense, readily available, and cheap fertilizer. Parthenium can also be used as an herbicide, an insecticide, and a phyto-remedial mediator to extract metals and dyes from agricultural waste. Here we provide basic information on the morphology, reproduction, environmental impacts, and management of this species. Effects of methanol, ethanol, hexane, acetone, and aqueous (water) Parthenium extracts are described. Because P. hysterophorus is said to be one of the world’s seven worst weeds, some control measures, including mechanical, chemical, cultural, and biological control, are discussed. The allelopathy of this weed is difficult to regulate, and there are both positive and negative interactions between Parthenium and other species due to allelochemical action. Several toxic phenolic compounds produced by P. hysterophorus are responsible for weed suppression, and we discuss details of their mode of action and potential applications. Full article

Isatis tinctoria L. (Brassicaceae), which is commonly known as woad, is a species with an ancient and well-documented history as an indigo dye and medicinal plant. Currently, I. tinctoria is utilized more often as medicinal remedy and also as a cosmetic ingredient. In 2011, I. tinctoria root was accepted in the official European phytotherapy by introducing its monograph in the European Pharmacopoeia. The biological properties of raw material have been known from Traditional Chinese Medicine (TCM). Over recent decades, I. tinctoria has been investigated both from a phytochemical and a biological point of view. The modern in vitro and in vivo scientific studies proved anti-inflammatory, anti-tumour, antimicrobial, antiviral, analgesic, and antioxidant activities. The phytochemical composition of I. tinctoria has been thoroughly investigated and the plant was proven to contain many valuable biologically active compounds, including several alkaloids, among which tryptanthrin, indirubin, indolinone, phenolic compounds, and polysaccharides as well as glucosinolates, carotenoids, volatile constituents, and fatty acids. This article provides a general botanical and ethnobotanical overview that summarizes the up-to-date knowledge on the phytochemistry and biological properties of this valuable plant in order to support its therapeutic potential. Moreover, the biotechnological studies on I. tinctoria, which mainly focused on hairy root cultures for the enhanced production of flavonoids and alkaloids as well as on the establishment of shoot cultures and micropropagation protocols, were reviewed. They provide input for future research prospects. Full article