The influence of magnetic particle incorporation on bisphenol A removal by β-cyclodextrin-derived sorbent

Adsorption of Bisphenol A onto β-Cyclodextrin-Based Nanosponges and Innovative Supercritical Green Regeneration of the Sustainable Adsorbent

Bisphenol A is a widely recognized endocrine disruptor that persists in ecosystems, harms aquatic organisms, and contributes to ecological degradation, raising global environmental concerns. Numerous studies have explored β-cyclodextrin-based adsorbents for Bisphenol A removal; however, their regeneration remains a major challenge, often relying on energy-intensive processes and excessive use of organic solvents. In this study, Bisphenol A was selected as a model pollutant, and its adsorption onto β-cyclodextrin nanosponges was investigated. After adsorption, Bisphenol A was efficiently recovered from the saturated β-cyclodextrin nanosponges using an innovative and sustainable supercritical CO2-based green process, which simultaneously regenerated the adsorbent. The adsorption process achieved an efficiency of 95.51 ± 0.82% under optimized conditions (C0 = 150 mg/L, mβ-CDNS = 0.15 g, T = 25 °C, and N = 200 rpm), with a maximum adsorption capacity of 47.75 ± 0.28 mg/g. The regeneration process achieved over 99% efficiency at 60 °C and 300 bar, with 10% (v/v) ethanol as a co-solvent, nearly fully restoring the adsorbent's performance. Unlike conventional regeneration techniques, this green approach eliminates the need for environmentally harmful organic solvents while preserving the adsorbent's structural integrity, making it a highly efficient and sustainable alternative. This study is the first to demonstrate the effective application of supercritical CO2-based regeneration for β-cyclodextrin nanosponges in Bisphenol A removal, providing a scalable and environmentally sustainable solution for wastewater treatment. Furthermore, characterization analyses confirmed that the adsorbent retained its chemical and morphological stability after adsorption and regeneration.

Novel anionic functionalized magnetic β-cyclodextrin composites with excellent adsorption capacity for moxifloxacin and wide pH adaptive adsorption capability for copper ion

Antibiotics and heavy metals pose severe risks to human health and ecological environment. Therefore, developing a multifunctional adsorbent to remove these contaminants from wastewater is an urgent need. Herein, novel anionic sulfonic acid groups functionalized magnetic β-cyclodextrin (β-CD) composites (FCD@AA) were synthesized by coating poly(2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS)) on the surface of magnetic β-CD particles (FCD). Several characterization techniques were utilized to comprehensively analyze the surface physicochemical properties of FCD@AA. The adsorption properties of FCD@AA toward antibiotics (moxifloxacin (MOX) as model) and heavy metals (copper ion (Cu2+) as model) were systematically studied under different conditions on adsorption time, temperature, initial concentration, solution pH and coexisting ionic strength. In single systems, the adsorption isotherm data for MOX and Cu2+ were well fitted to Langmuir and Freundlich models, respectively. The maximum adsorption capacities of FCD@AA toward MOX and Cu2+ were 118.98 and 19.29 mg g-1, respectively. The pseudo-second-order model could better describe the kinetic processes. In binary systems, the presence of Cu2+ exhibited a pronounced antagonism on the adsorption of MOX. The influence of co-existing MOX on the capture of Cu2+ changed from inhibition to promotion as the initial Cu2+ concentration increased. And after five adsorption cycles, FCD@AA still had satisfactory reusability. The results indicate that FCD@AA is a promising adsorbent for treating water contaminated by MOX and Cu2+, which broadens the application of magnetic β-CD adsorbents in environmental protection.

Application of terpenoids for the remediation of environmental water polluted with bisphenol A and its analogs using an in silico approach

Nowadays, there is a global concern over water quality and the impact of contamination on both natural ecosystems and human well-being. Plastics, ubiquitous in modern life, may release harmful chemicals when they reach aquatic environments. Among them, bisphenol A (BPA) and its alternatives, such as bisphenol S (BPS), bisphenol F (BPF), and others, are of special concern because their presence in water systems can have detrimental effects on human health and aquatic organisms due to their endocrine-disrupting properties. This study explores the potential of terpenoids, sustainable and environmentally friendly solvents, for efficiently removing bisphenols from contaminated environmental water. Using an in silico approach based on the Conductor-like Screening Model for Realistic Solvents (COSMO-RS) theory, more than 30 terpenoids were screened, and carvone was found to be an excellent candidate due to its high solvent capacity and low toxicity. The impact of pH, temperature, stirring conditions, and sample:extractant phase ratios on the extraction efficiency were investigated. A design of experiments revealed optimal conditions for the extraction process and demonstrated that carvone can effectively extract bisphenols (nearly 100 % for most of them) under a wide range of conditions, showing the robustness and efficiency of the extraction method, even in environmental samples. The paper provides valuable insights into the potential of terpenoids, specifically carvone, as a sustainable and eco-friendly solvent for removing bisphenol contaminants from environmental water bodies. The findings of this study offer a promising solution to address water contamination issues, aligning with the principles of Green Chemistry and contributing to a more environmentally responsible approach to water remediation.

Activated persulfate for efficient bisphenol A degradation via nitrogen-doped Fe/Mn bimetallic biochar

To achieve the purpose of treating waste by waste, in this study, a nitrogen-doped Fe/Mn bimetallic biochar material (FeMn@N-BC) was prepared from chicken manure for persulfate activation to degrade Bisphenol A (BPA). The FeMn@N-BC was characterized by scanning electron microscopy (SEM), X-ray diffract meter (XRD), fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectrometer (XPS) and found that N doping can form larger specific surface area. Catalytic degradation experiments showed that Fe/Mn bimetal doping not only accelerated the electron cycling rate on the catalyst surface, but also makes the biochar magnetic and easy to separate, thus reducing environmental pollution. Comparative experiments was concluded that the highest degradation efficiency of BPA was achieved when the mass ratios of urea and chicken manure, Fe/Mn were 3:1 and 2:1, respectively, and the pyrolysis temperature was 800 °C, which can almost degrade all the BPA in 60 min. FeMn@N-BC/PS system with high catalytic efficiency and low consumables is promising for reuse of waste resources and the remediation of wastewater.

Studies on the Removal of Malachite Green from Its Aqueous Solution Using Water-Insoluble β-Cyclodextrin Polymers

The rising global pollution of natural waters by dyes has brought to light the need for adaptable and efficient removal techniques. To create water-insoluble β-cyclodextrin (β-CD) polymers like CA/-CD, TA/-CD, and MA/-CD, several organic acids including citric acid (CA), tartaric acid (TA), and malic acid (MA) were cross-linked with β-cyclodextrin in this study. The obtained polymers were characterized by different advanced analytical techniques such as FTIR, SEM, and UV-vis spectrophotometry. Malachite green dye was removed from aqueous solutions using the synthesized polymers by adsorption. The adsorption investigation was conducted under several conditions, including pH, adsorbent mass, dye concentration, temperature, contact time, adsorption isotherm, and kinetics. The adsorbent CA/β-CD shows the highest adsorption of MG dye in all of the conditions because it contains a high number of carboxyl groups. The negatively charged carboxyl ions of CA/β-CD attract the positively charged MG dye electrostatically and remove MG from aqueous media with an efficiency of 91%. As a result, the findings indicated that water-insoluble polymers based on β-cyclodextrin are well-suited as inexpensive adsorbents to remove colors from aqueous media.

β-cyclodextrin polymer composites for the removal of pharmaceutical substances, endocrine disruptor chemicals, and dyes from aqueous solution- A review of recent trends

Cyclodextrin (CD) and its derivatives are receiving attention as a new-generation adsorbent for water pollution treatment due to their external hydrophilic and internal hydrophobic properties. Among types of CD, β-Cyclodextrin (βCD) has been a material of choice with a proven track record for a range of utilities in distinct domains, owing to its unique cage-like structural conformations and inclusion complex-forming ability, especially to mitigate emerging contaminants (ECs). This article outlines βCD composites in developing approaches of their melds and composites for purposes such as membranes for removal of the ECs in aqueous setups have been explored with emphasis on recent trends. Electrospinning has bestowed an entirely different viewpoint on polymeric materials, comprising βCD, in the framework of diverse functions across a multitude of niches. Besides, this article especially discusses βCD polymer composite membrane-based removal of contaminants such as pharmaceutical substances, endocrine disruptors chemicals, and dyes. Finally, in this article, the challenges and future directions of βCD-based adsorbents are discussed, which may shed light on pragmatic commercial applications of βCD polymer composite membranes.