The effective treatment of dye-containing simulated wastewater by using the cement kiln dust as an industrial waste adsorbent.

This study compares the adsorption behavior of both Methylene Blue (MB) and Congo Red (CR) dyes on the surfaces of cement kiln dust (CKD) powder from the experimentally simulated wastewater solution. The cement kiln dust powder was characterized using X-ray Fluorescence (XRF), X-ray diffraction (XRD), N2 adsorption-desorption Brunauer-Emmett-Teller (BET), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) tests. The adsorption for such dyes was studied under varying mixing contact times, temperatures, and pH as well as various initial concentrations of both dyes and adsorbent using the batch mode experiments. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were applied, and the results revealed that the pseudo-second-order fitted well to the kinetic data. Thermodynamic parameters stated that the adsorption process was endothermic. Studying Linear and nonlinear forms of Langmuir and Freundlich's adsorption isotherms revealed that the adsorption process was followed by both homogeneous mono-layer and heterogeneous multilayer coverage on the active sites of cement kiln dust particles. The data showed that the adsorption capacities of the methylene blue and Congo red dyes were 58.43 and 123.42 mg/g, respectively and cement kiln dust is an adsorbent with little cost for the treatment of wastewater.

Synthetic Degradable Polyvinyl Alcohol Polymer and Its Blends with Starch and Cellulose-A Comprehensive Overview.

Approximately 50% of global plastic wastes are produced from plastic packaging, a substantial amount of which is disposed of within a few minutes of its use. Although many plastic types are designed for single use, they are not always disposable. It is now widely acknowledged that the production and disposal of plastics have led to a plethora of negative consequences, including the contamination of both groundwater and soil resources and the deterioration of human health. The undeniable impact of excessive plastic manufacturing and waste generation on the global plastic pollution crisis has been well documented. Therefore, degradable polymers are a crucial solution to the problem of the non-degradation of plastic wastes. The disadvantage of degradable polymers is their high cost, so blending them with natural polymers will reduce the cost of final products and maximize their degradation rate, making degradable polymers competitive with industrial polymers that are currently in use daily. In this work, we will delineate various degradable polymers, including polycaprolactone, starch, and cellulose. Furthermore, we will elucidate several aspects of polyvinyl alcohol (PVA) and its blends with natural polymers to show the effects of adding natural polymers on PVA properties. This paper will study cost-effective and ecologically acceptable polymers by combining inexpensive natural polymers with readily accessible biodegradable polymers such as polyvinyl alcohol (PVA).

Biodegradable cellulose nanocrystals hydrogels for removal of acid red 8 dye from aqueous solutions.

Biodegradable cellulose nanocrystals hydrogels (CNCsH) were synthesized from cellulose nanocrystals (CNCs) which were prepared from office wastepaper (OWP) by a chemical crosslinking method using epicholorohydrin (ECH) as a cross-linker. CNCsH were tested for their swelling behavior and biodegradability and the point of zero charge had been determined. The ability of CNCsH for removing the Acid Red 8 (AR8) anionic dye from its aqueous solution was evaluated. The different parameters affecting removal of the dye, such as pH, initial concentration of dye, content of CNCs, temperature and adsorbent dosage were investigated. The optimum conditions for 68% removal efficiency were pH = 1, initial concentration of dye = 10 ppm, contact time = 105 min, CNCs content = 5% and CNCsH dosage = 0.5 g at 30 °C. The adsorption isotherms, kinetics, and thermodynamic parameters have been studied. The results showed an appropriate fit for Langmuir adsorption isotherm and pseudo-second order kinetics model with an adsorption capacity of 17.12 mg/g. According to the obtained values of thermodynamic parameters, the removal of Acid red 8 by CNCs hydrogels was exothermic spontaneous process.

The superior photocatalytic performance and DFT insights of S-scheme CuO@TiO2 heterojunction composites for simultaneous degradation of organics.

The necessity to resolve the issue of rapid charge carrier recombination for boosting photocatalytic performance is a vigorous and challenging research field. To address this, the construction of a binary system of step-scheme (S-scheme) CuO@TiO2 heterostructure composite has been demonstrated through a facile solid-state route. The remarkably enhanced photocatalytic performance of CuO@TiO2, compared with single TiO2, which can consequence in the more efficient separation of photoinduced charge carriers, reduced the band gap of TiO2, improved the electrical transport performance, and improved the lifetimes, thus donating it with the much more powerful oxidation and reduction capability. A photocatalytic mechanism was proposed to explain the boosted photocatalytic performance of CuO@TiO2 on a complete analysis of physicochemical, DFT calculations, and electrochemical properties. In addition, this work focused on the investigation of the stability and recyclability of CuO@TiO2 in terms of efficiency and its physical origin using XRD, BET, and XPS. It is found that the removal efficiency diminishes 4.5% upon five recycling runs. The current study not only promoted our knowledge of the binary system of S-scheme CuO@TiO2 heterojunction composite photocatalyst but also shed new light on the design of heterostructure photocatalysts with high-performance and high stability.

Innovative high-density polyethylene/waste glass powder composite with remarkable mechanical, thermal and recyclable properties for technical applications.

Several reinforcement materials are incorporated into a polymeric matrix to improve the mechanical properties and reduce the cost of the obtained composites. In this work, recycled high-density polyethylene/waste glass powder composites, compatibilized with maleic anhydride-grafted polyethylene, were prepared using a two-roll mill and compression molding techniques. Four levels of waste glass powder, 2, 10, 20 and 30% by weight, and five levels of the compatibilizer, polyethylene grafted with maleic anhydride (0.5, 1.5, 2.5, 5 and 7.5%by weight), were used. The effect of adding waste glass powder and compatibilizer concentration on the composite's mechanical properties, such as tensile strength, tensile strain, tensile modulus and thermal properties was studied. The results showed that superior mechanical properties were obtained and that the tensile strength and modulus increased with increasing waste glass powder content and compatibilizer concentration by 20 and 1.5 wt%, respectively. However, the elongation at the break decreased with the increase in both factors. The composite, which was prepared under ideal conditions, has high thermal stability and can be easily recycled and reprocessed for five cycles with high mechanical properties. This study recommends that the prepared composite, under optimum conditions, can be used as a cost-effective automobile dashboard material.