The facile preparation and modification of low-cost/efficient adsorbents or biochar (CP) derived from the carbonization of palm kernel cake (lignocellulosic residue) has been studied for the selective adsorption of various metal cations, such as Fe, Fe, Ca and Zn, from aqueous solution. The CP surface was modified with KMnO (CPMn) and HNO (CPHNO) in order to improve the adsorption efficiency. The physicochemical properties of the as-prepared adsorbents were investigated BET, pH, FT-IR, Boehm titration, TG-DTG, XRD and SEM-EDS techniques. The surfaces of all adsorbents clearly demonstrated negative charge (pH > pH of the mixture solution), resulting in a high adsorption capacity for each metal cation. Fe was found to be more easily adsorbed on modified CP than the other kinds of metal cations. Synergistic effects between the carboxylic groups and MnO on the surface of CPMn resulted in better performance for metal cation adsorption than was shown by CPHNO. The maximum adsorption capacities for Fe, Fe, Ca and Zn using CPMn, which were obtained from a monolayer adsorption process Langmuir isotherms ( > 0.99), were 70.67, 68.60, 5.06 and 22.38 mg g, respectively. The adsorption behavior and monolayer-physisorption behavior, a rapid adsorption process as well as single-step intra-particle diffusion, were also verified and supported using Dubinin-Radushkevich, Redlich-Peterson and Toth isotherms, a pseudo-second-order kinetic model and the Weber-Morris model. Moreover, the thermodynamic results indicated that the adsorption process of metal cations onto the CPMn surface was endothermic and spontaneous in nature. This research is expected to provide a green way for the production of low-cost/efficient adsorbents and to help gain an understanding of the adsorption behavior/process for the selective removal of metal ions from wastewater pollution.
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http://dx.doi.org/10.1039/c9ra03112j | DOI Listing |
Sci Rep
December 2024
Department of Electrical and Computer Engineering, Ajou University, Suwon, 16499, Republic of Korea.
pH sensing technology is pivotal for monitoring aquatic ecosystems and diagnosing human health conditions. Indium-gallium-zinc oxide electrolyte-gated thin-film transistors (IGZO EGTFTs) are highly regarded as ion-sensing devices due to the pH-dependent surface chemistry of their sensing membranes. However, applying EGTFT-based pH sensors in complex biofluids containing diverse charged species poses challenges due to ion interference and inherently low sensitivity constrained by the Nernst limit.
View Article and Find Full Text PDFJ Control Release
December 2024
Department of Chemical Engineering, McMaster University, 1280 Main Street, West Hamilton, ON L8S 4L8, Canada. Electronic address:
While bipolar disorder patients can benefit from lithium therapy, high levels of lithium in the serum can induce undesirable systemic side effects. Intranasal (IN) lithium delivery offers a potential solution to this challenge given its potential to facilitate improved lithium transport to brain when delivered to the olfactory mucosa. Herein, a sprayable, in situ forming nanoparticle network hydrogel (NNH) based on Schiff base interactions between chelator-functionalized oxidized starch nanoparticles (SNPs) and carboxymethyl chitosan (CMCh) is reported that can be deployed within the nasal cavity to release ultra-small penetrative SNPs over time.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.
Designing catalysts with well-defined active sites with chemical functionality responsive to visible light has significant potential for overcoming scaling relations limiting chemical reactions over heterogeneous catalyst surfaces. Visible light can be leveraged to facilitate the removal of strongly bound species from well-defined single cationic sites (Rh) under mild conditions (323 K) when they are incorporated within a photoactive perovskite oxide (Rh-doped SrTiO). CO, a key intermediate in many chemistries, forms stable geminal dicarbonyl Rh complexes (Rh(CO)), that could act as site blockers or poisons during a catalytic cycle.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Material Science, BASF SE, RGA/BM-B007, Carl-Bosch-Str. 38, D-67056 Ludwigshafen, Germany.
The controlled formation and stabilization of nanoparticles is of fundamental relevance for materials science and key to many modern technologies. Common synthetic strategies to arrest growth at small sizes and prevent undesired particle agglomeration often rely on the use of organic additives and require non-aqueous media and/or high temperatures, all of which appear critical with respect to production costs, safety, and sustainability. In the present work, we demonstrate a simple one-pot process in water under ambient conditions that can produce particles of various transition metal carbonates and sulfides with sizes of only a few nanometers embedded in a silica shell, similar to particles derived from more elaborate synthesis routes, like the sol-gel process.
View Article and Find Full Text PDFJ Xenobiot
December 2024
Department of Chemical Engineering, University of Pretoria, Pretoria 0028, South Africa.
The direct discharge of cationic surfactants into environmental matrices has exponentially increased due to their wide application in many products. These compounds and their degraded products disrupt microbial dynamics, hinder plant survival, and affect human health. Therefore, there is an urgent need to develop electroanalytical assessment techniques for their identification, determination, and monitoring.
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