Fluorescent carbon quantum dots (CQDs) were prepared by an economical, green, and single-step procedure with the assistance of microwave heating of urea with bagasse (SCB), cellulose (C), or carboxymethyl cellulose (CMC). The prepared CQDs were characterized using a series of spectroscopic techniques, and they had petite size, intense absorption in the UV, and excitation wavelength-dependent fluorescence. The prepared CQDs were used for Pb(II) adsorption from an aqueous solution. The removal efficiency percentages (R %) were 99.16, 96.36, and 98.48% for QCMC, QC, and QSCB, respectively. The findings validated the efficiency of CQDs synthesized from CMC, cellulose, and SCB as excellent materials for further utilization in the environmental fields of wastewater pollution detection, adsorption, and chemical sensing applications. The kinetics and isotherms studied found that all CQDs isotherms fit well with the Langmuir model than Freundlich and Temkin models. According to R², the pseudo-second-order fits the adsorption of QCMC, while the first-order one fits with QC and QSCB.

A novel magnetic hydrogel loaded with graphene oxide (GO) was developed in this study. Firstly, GO was prepared from bagasse through a single step via oxidation in the presence of ferrocene under muffled atmospheric conditions, followed by the loading of different amounts of magnetite onto GO via co-precipitation reaction of iron onto GO sheets. Finally, the 2-acrylamido-2-methyl-1-propane sulfonic acid was grafted onto carboxymethyl cellulose in the presence of magnetite GO and N, N′-methylenebisacrylamide as crosslinker yielded hydrogel. The structure, morphological, and thermal behavior of the prepared hydrogels were investigated. In addition, the adsorption performance of Ni(II) ions from aqueous media by the prepared hydrogels was investigated as a function of temperature, time, and concentration of adsorbate in a batch system. The results demonstrated a remarkable enhancement in the adsorption process of Ni(II) (Removal efficiency = 98.82%). All isotherms were found to fit the Langmuir model best. The adsorption properties of both magnetic GO and magnetic hydrogel showed promising properties as green and cheap adsorbents.

In this work, we prepared highly swelling, stimuli-responsive hydrogels capable of the highly efficient adsorption of inorganic pollutants. The hydrogels were based on hydroxypropyl methyl cellulose (HPMC) grafted with acrylamide (AM) and 3-sulfopropyl acrylate (SPA) and were synthesized via the growth (radical polymerization) of the grafted copolymer chains on HPMC, which was activated by radical oxidation. These grafted structures were crosslinked to an infinite network by a small amount of di-vinyl comonomer. HPMC was chosen as a cheap hydrophilic and naturally sourced polymer backbone, while AM and SPA were employed to preferentially bond coordinating and cationic inorganic pollutants, respectively. All the gels displayed a pronounced elastic character, as well as considerably high values of stress at break (several hundred %). The gel with the highest fraction of the ionic comonomer SPA (with an AM/SPA ratio = 0.5) displayed the highest equilibrium swelling ratio (12,100%), the highest volume response to temperature and pH, and the fastest swelling kinetics, but also the lowest modulus. The other gels (with AM/SPA = 1 and 2) displayed several times higher moduli but more modest pH responses and only very modest temperature sensitivity. Cr(VI) adsorption tests indicated that the prepared hydrogels removed this species from water very efficiently: between 90 and 96% in one step. The hydrogels with AM/SPA ratios of 0.5 and 1 appeared to be promising regenerable (via pH) materials for repeated Cr(VI) adsorption.

Lignocellulosic materials (LCMs), abundant biomass residues, pose significant environmental challenges when improperly disposed of. LCMs, such as sugarcane bagasse, rice straw, saw dust and agricultural residues, are abundan... | Find, read and cite all the research you need on Tech Science Press