Advanced technologies in water treatment: Chitosan and its modifications as effective agents in the adsorption of contaminants.

Chitosan, derived from the abundant biopolymer chitin, has emerged as a promising option for water treatment due to its intrinsic bioavailability. This review emphasizes the notable characteristics of chitosan, which allow for various modifications, expanding its applications. The polymer's effectiveness in adsorbing contaminants, particularly in advanced water treatment technologies, is highlighted.

Geochemistry and the optics of geospatial analysis as a preposition of water quality on a macroscale.

The water treatment depends exclusively on the identification of residues containing toxic chemical elements accumulated in NPs (nanoparticles), and ultrafine particles sourced from waste piles located at old, abandoned sulfuric acid factories containing phosphogypsum requires global attention. The general objective of this study is to quantify and analyze the hazardous chemical elements present in the leachate of waste from deactivated sulfuric acid factories, coupled in NPs and ultrafine particles, in the port region of the city of Imbituba, Santa Catarina, Brazil. Samples were collected in 2020, 2021, and 2022.

New and effective cassava bagasse-modified biochar to adsorb Food Red 17 and Acid Blue 9 dyes in a binary mixture.

A promissory technic for reducing environmental contaminants is the production of biochar from waste reuse and its application for water treatment. This study developed biochar (CWb) and NHCl-modified biochar (MCWb) using cassava residues as precursors. CWb and MCWb were characterized and evaluated in removing dyes (Acid Blue 9 and Food Red 17) in a binary system.

Development of a biosponge based on Luffa cylindrica and crosslinked chitosan for Allura red AC adsorption.

A new bioadsorbent from Luffa cylindrica and cross-linked chitosan was proposed in the present study. Luffa was used as a natural support medium for chitosan crosslinked with glutaraldehyde (LCsG) and epichlorohydrin (LCsE). Biosponges were applied to remove Allura red from aqueous solutions.

Identification of hazardous nanoparticles present in the Caribbean Sea for the allocation of future preservation projects.

The deposition of remaining nanoparticles in the Caribbean Sea generates the formation of potentially dangerous elements, which influence at the imbalance of ecosystems. The detection of nanoparticles is not simple and the use of conventional methods is difficult application, which is why we highlight the immediacy and importance of this research for the areas of marine biology, urbanism, engineering and geosciences, applied in the Caribbean Sea. The general objective of this study is to evaluate the use of advanced methods for the determination of toxic nanoparticles, which can directly affect the development of marine organisms in the aquatic ecosystem in waters of the Caribbean Sea, favoring the construction of future international public policies with the elaboration of projects capable of mitigating these levels of contamination.

Chitin-psyllium based aerogel for the efficient removal of crystal violet from aqueous solutions.

A new alternative aerogel was prepared from low-cost chitin and psyllium biopolymers to adsorb crystal violet (CV) dye from liquid media and possibly treat effluents containing other dyes. The aerogel was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), which demonstrated that aerogel has a typical structure of amorphous materials and presented a randomly interconnected porous structure that resembles an open pore network. 2.

Soil contamination in Colombian playgrounds: effects of vehicles, construction, and traffic.

The presence of potentially hazardous elements (PHEs) in playground soils is generally associated with anthropogenic sources such as vehicle traffic, industries, construction sites, and biomass burning. Studies indicate that PHEs are harmful to human health and may even be carcinogenic. Therefore, the aim of this study was to evaluate the physicochemical, morphological, and mineralogical properties of soil samples from three public playgrounds located in the cities of Bogota, Medellin, and Barranquilla.

Identification of mercury and nanoparticles in roots with different oxidation states of an abandoned coal mine.

The morphology and composition of roots with different degrees of oxidation as a function of time were evaluated aiming to identify possible hazardous elements and nanoparticles. The roots were obtained from an abandoned coal mine located in the city of Criciúma, Santa Catarina, Brazil. From the roots, analyses were performed to identify nanoparticles (NPs) and ultrafine particles (UFPs), containing possible hazardous elements (PHEs) that cause potential environmental risks and impacts on human health.

Removal of fluoride from fertilizer industry effluent using carbon nanotubes stabilized in chitosan sponge.

Adsorption of fluoride from fertilizer industry effluent using carbon nanotubes stabilized in chitosan sponge as adsorbent was evaluated. The effluent was produced in the washing of acid gases during the reaction in fertilizer production and all assays were performed using this hazardous material. Adsorbent characterization and ions interactions were elucidated from differential scanning calorimetry, thermal gravimetric analyses, X-ray diffraction, scanning electron microscopy dispersive energy X-ray spectroscopy, atomic force microscopy and X-ray photoelectron spectroscopy.

Solid wastes from the enzyme production as a potential biosorbent to treat colored effluents containing crystal violet dye.

Sugarcane bagasse, a largely available waste worldwide, was submitted to solid-state fermentation (SSF) using the fungus Metarhizium anisopliae, aiming to produce enzymes. The solid waste generated from SSF was tested as an alternative biosorbent to treat colored effluents containing crystal violet (CV) dye. The biosorbent, here named BW (bagasse waste), was characterized, and experimental tests were performed to verify the influence of pH and dosage on the CV biosorption.

Chitosan hydrogel scaffold modified with carbon nanotubes and its application for food dyes removal in single and binary aqueous systems.

This work developed one promising adsorbent based on chitosan hydrogel scaffold modified with carbon nanotubes, for food dye removal in single and binary aqueous systems. The modified hydrogel scaffold was characterized in relation to the gel strength, swelling degree, surface attributes, and infrared spectrum. Adsorption isotherms were performed using dyes, food red 17 (FdR17) and food blue 1 (FdB1), in single and binary aqueous systems.

Separation of anthocyanins extracted from red cabbage by adsorption onto chitosan films.

Anthocyanin pigments are suitable as natural dyes for food, cosmetics and dietary supplements, due to the demand for healthier products and their antioxidant properties. This work aimed to extract the anthocyanin pigments from red cabbage and its separation of the solution by adsorption operation onto chitosan films. The anthocyanin was extracted from red cabbage in water hot at 90 °C by 15 min.

Synthesis of a bio-based polyurethane/chitosan composite foam using ricinoleic acid for the adsorption of Food Red 17 dye.

A novel bio-based polyurethane/chitosan foam (PU/chitosan) was synthesized using a polyol derived from castor oil and applied to remove Food Red 17 dye (FR17) from aqueous solutions. PU/chitosan foam presented better characteristics and adsorption potential than polyurethane foam (PU). PU/chitosan foam showed a semi-crystalline structure, with several functional groups, high porosity and good mechanical properties.