Crystalline phase evolution behavior and physicochemical properties of glass–ceramics from municipal solid waste incineration fly ash

Journal of Material Cycles and Waste Management - Appropriate management and treatment of fly ash from municipal solid waste (MSW) incineration plant have become an urgent environmental protection...     

Structural characterization and visible light activated photocatalytic ability of glass–ceramics prepared from municipal solid waste

Journal of Material Cycles and Waste Management - The relationship between local structure and visible-light-activated photocatalytic ability of glass–ceramics prepared from Municipal Solid...     

Recovery of platinum and synthesis of glass–ceramic from spent automotive catalyst via co-treatment process with coal fly ash

Journal of Material Cycles and Waste Management - Spent automotive catalyst (SAC) has attracted attention because of containing platinum group metals (PGMs) along with hazardous materials such as...     

Characterization of different types of electronic waste: heavy metal,precious metal and rare earth element content by comparing different digestıon methods

Journal of Material Cycles and Waste Management - Electronic waste is one of the fastest-growing waste streams. The content of this waste has critical importance for the development or adoption of...     

Preparation and Properties of Chitosan–PVA Fibers Produced by Wet Spinning

Chitosan fibers were prepared by wet spinning in three stages. Initially, a polymer solution of chitosan and polyvinyl alcohol (PVA) was solidified in a mixture of potassium hydroxide and ethanol. The polymers were then crosslinked with sodium tripolyphosphate (TPP) or glutaraldehyde, and finally dried in methanol or acetone. The effect of these conditions was evaluated based on scanning electron microscopy images, water-holding capacity, and swelling and mechanical properties. The miscibility of the mixture was evaluated using Fourier Transform Infrared spectroscopy and differential scanning calorimetry. The results obtained showed that chitosan fibers containing 45% (v/v) PVA and crosslinked using TPP have properties similar to those of commercial sutures prepared using other biomaterials.     

Physical–chemical processes of sustainable materials’ production from hazardous toner waste,galvanic glass waste and spent foundry sand

Journal of Material Cycles and Waste Management - Several sustainable white ceramic composites were prepared from 3 to 7 wt.% of hazardous toner waste, 30–40% of spent foundry sand,...     

Correction to: Preparation and properties of fly ash‑based geopolymer concrete with alkaline waste water obtained from foundry sand regeneration process

Journal of Material Cycles and Waste Management - A correction to this paper has been published: https://doi.org/10.1007/s10163-021-01257-w     

Preparation and Properties of a Chitosan–Hyaluronic Acid-Polypyrrole Conductive Hydrogel Catalyzed by Laccase

Electro conductive hydrogels, consisting of chitosan (CS), hyaluronic acid (HA), and polypyrrole (PPy), were prepared via an in situ enzymic polymerization of pyrrole in the CS–HA hydrogel, using laccase as the catalyst. This CS–HA–PPy composite hydrogel showed good conductivity. The chemical structure and morphology of this conductive hydrogel were studied by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction technique. For CS–HA–PPy and CH–HA hydrogel, the temperature at which fastest decomposition occurred was 260 and 244 °C, respectively. That means the thermal stability of CS–HA–PPy is better than CS–HA hydrogel. The conductive hydrogel also showed excellent swelling and deswelling behaviors.     

Characterization and recycling of cadmium from waste nickel–cadmium batteries

A severe threat was posed due to improper and inefficient recycling of waste batteries in China. The present work considered the fundamental aspects of the recycling of cadmium from waste nickel–cadmium batteries by means of vacuum metallurgy separation in scale-up. In the first stage of this work, the characterization of waste nickel–cadmium batteries was carried out. Five types of batteries from different brands and models were selected and their components were characterized in relation to their elemental chemical composition and main phase. In the second stage of this work, the parameters affecting the recycling of cadmium by means of vacuum metallurgy separation were investigated and a L₁₆ (4⁴) orthogonal design was applied to optimize the parameters. With the thermodynamics theory and numerical analysis, it can be seen that the orthogonal design is an effective tool for investigating the parameters affecting the recycling of cadmium. The optimum operating parameters for the recycling of cadmium obtained by orthogonal design and verification test were 1073 K (temperature), 2.5 h (heating time), 2 wt.% (the addition of carbon powder), and 30 mm (the loaded height), respectively, with recycling efficiency approaching 99.98%. The XRD and ICP-AES analyzed results show that the condensed product was characterized as metallic cadmium, and cadmium purity was 99.99% under the optimum condition.     

Glass–ceramic from mixtures of bottom ash and fly ash

Along with the gradually increasing yield of the residues, appropriate management and treatment of the residues have become an urgent environmental protection problem. This work investigated the preparation of a glass–ceramic from a mixture of bottom ash and fly ash by petrurgic method. The nucleation and crystallization kinetics of the new glass–ceramic can be obtained by melting the mixture of 80% bottom ash and 20% fly ash at 950 °C, which was then cooled in the furnace for 1 h. Major minerals forming in the glass–ceramics mainly are gehlenite (Ca₂Al₂SiO₇) & akermanite (Ca₂MgSiO₇) and wollastonite (CaSiO₃). In addition, regarding chemical/mechanical properties, the chemical resistance showing durability, and the leaching concentration of heavy metals confirmed the possibility of engineering and construction applications of the most superior glass–ceramic product. Finally, petrurgic method of a mixture of bottom ash and fly ash at 950 °C represents a simple, inexpensive, and energy saving method compared with the conventional heat treatment.     

Preparation of Magadiite-Sodium Alginate Drug Carrier Composite by Pickering-Emulsion-Templated-Encapsulation Method and Its Properties of Sustained Release Mechanism by Baker–Lonsdale and Korsmeyer–Peppas Model

Journal of Polymers and the Environment - In this study, the nanohybrid drug carrier were synthesized by Pickering emulsion-templated encapsulation (PETE) method to control the...     

Recovery of Kraft Lignin from OPEFB and Using for Lignin–Agarose Hydrogel

Lignins from the spent pulping liquor were normally acquired as waste product of pulp and paper mills. The possibilities of utilizing kraft lignin have yet been developed for commercial innovation. The objectives of this research are to recovery and utilization of lignin from black liquor of oil palm empty fruit bunches (OPEFBs). Kraft lignins from the OPEFBs black liquor were recovered by acidification procedure. They were precipitated at pH 4, 3, and 2 in order that determine the optimum pH for isolation. It can be clearly seen that the best condition of lignin precipitation was at pH 3. It offered the highest yield and purity. The kraft lignin and agarose were utilized as the crude material for the production of lignin–agarose hydrogel. Lignin–agarose hydrogel could be prepared by using epichlorohydrin as the cross-linking agent. The cross-linking occurrence was recognized by FTIR. Physical and chemical properties of hydrogel were investigated. Gel strength of lignin–agarose hydrogel was characterized by texture personal analysis. The results demonstrated that the gel strength increased with increasing of lignin and epichlorohydrin (ECH) in agarose solutions. 5% lignin, 5% agarose and 10 mL ECH contributed the best gel formation and the great mechanical properties. The effect of cross-linking condition on the gel properties, for example, gel hardness and fracturability, was examined.     

Molecular sieve material from liquid–crystal-display waste glass and silicon carbide sludge via hydrothermal process with alkali fusion pretreatment

Journal of Material Cycles and Waste Management - The goal of this paper was to synthesize eco-humidity-conditioned Al-MCM-41 mesoporous molecular sieves (CHCMs) from liquid–crystal-display...     

Nickel recovery from electronic waste II Electrodeposition of Ni and Ni–Fe alloys from diluted sulfate solutions

This study focuses on the electrodeposition of Ni and Ni–Fe alloys from synthetic solutions similar to those obtained by the dissolution of electron gun (an electrical component of cathode ray tubes) waste. The influence of various parameters (pH, electrolyte composition, Ni²⁺/Fe²⁺ ratio, current density) on the electrodeposition process was investigated. Scanning electron microscopy (SEM) and X-ray fluorescence analysis (XRFA) were used to provide information about the obtained deposits’ thickness, morphology, and elemental composition. By controlling the experimental parameters, the composition of the Ni–Fe alloys can be tailored towards specific applications. Complementarily, the differences in the nucleation mechanisms for Ni, Fe and Ni–Fe deposition from sulfate solutions have been evaluated and discussed using cyclic voltammetry and potential step chronoamperometry. The obtained results suggest a progressive nucleation mechanism for Ni, while for Fe and Ni–Fe, the obtained data points are best fitted to an instantaneous nucleation model.     

Dynamic studies on lead volatilization from CaO–SiO2–Al2O3 molten slag under N2–CO–CO2, N2–HCl and N2–H2S gas atmospheres

Dynamic studies on the volatilization of lead from CaO–SiO₂–Al₂O₃ molten slags were conducted in a lab-scale melting furnace from 1623 to 1773 K under different mixed gas atmospheres of CO 0.05–0.3 atm to CO₂ 0–0.3 atm to N₂ (balance), HCl 1.7 × 10^?3–6.7 × 10^?3 atm to N₂ (balance), and H₂S 3.0 × 10^?4 to 1.7 × 10^?3 atm to N₂ (balance). The slag samples consisted of the mixed powders of 20–50 wt% CaO, 30–60 wt% SiO₂, and 10–40 wt% Al₂O₃, containing 2000 ppm PbO.Results showed that the rates of volatilization of lead from the CaO–SiO₂–Al₂O₃ molten slags under the N₂–CO–CO₂, N₂–HCl, and N₂–H₂S gas atmospheres were higher than those under the simulated air (N₂–O₂), which increased with CO, HCl, and H₂S partial pressures. At \(p_{{HCl}}\)  =  \(p_{H_{2}S}\)  = 1.7 × 10^?3 atm, the apparent rate constants for the volatilization of lead under the N₂–H₂S and N₂–HCl gas atmospheres were nearly equal, which increased with a rise in temperature. Results also showed that the rate of volatilization of lead from the molten slag decreased drastically with the increasing viscosity of the molten slag, in the viscosity range lower than 3 Pa s. Consequently, the volatilization of lead from the CaO–SiO₂–Al₂O₃ molten slag was significantly influenced by CO, HCl, and H₂S partial pressures and by the viscosity of the molten slag.     

Solidification of (Pb–Zn) mine tailings by fly ash-based geopolymer I: influence of alkali reagents ratio and curing condition on compressive strength

Journal of Material Cycles and Waste Management - Fly ash-based geopolymer is a crucial application for tackling climate change, limiting the production of greenhouse emissions. The main aim of...     

Preparation conditions and swelling equilibria of biodegradable hydrogels prepared from microbial poly(γ-glutamic acid) and poly(ε-lysine)

Biodegradable hydrogels prepared by -irradiation from microbial poly(amino acid)s are reviewed. pH-sensitive hydrogels were prepared by means of -irradiation of poly(-glutamic acid) (PGA) produced byBacillus subtilis IFO3335 and poly(-lysine) (PL) produced byStreptomyces albulus in aqueous solutions. The preparation conditions, swelling equilibria, hydrolytic degradation, and enzymatic degradation of these hydrogels were studied. A hydrogel with a wide variety of swelling behaviors has been produced by -irradiation from a mixture solution of PGA and PL.Paper presented at the 4th International Workshop on Biodegradable Plastics and Polymers, October 11–14, 1995, Durham, New Hampshire, USA.     

Preparation of zeolitic material with simultaneous removal of NH4 + and PO4 3− from paper sludge ash via acid leaching

This study investigates the preparation of zeolitic material with removal of both NH₄ ⁺ and PO₄ ^3? from paper sludge ash (PSA) via acid leaching. PSA typically has a low Si and high Ca content, owing to the presence of calcite fillers. Acid leaching with 3 M HCl was used firstly to reduce the Ca content of the PSA, whereafter a zeolite-P (Na-P) product with high cation exchange capacity (CEC) was synthesized through reaction with 2.5 M NaOH solution at 80 °C. Ca-P zeolitic products were prepared by Ca-treatment with the leachant that had been in contact with the PSA. The product with high CEC capacity including Na-P could be synthesized from the acid-leached ash, and the high Ca content in the ash could be reduced by extraction of the Ca into the leachant via the acid leaching. The Ca-P zeolitic product could be prepared by Ca-treatment with the solution obtained from neutralization of the leachant with NaOH. This product was capable of removing NH₄ ⁺ and PO₄ ^3? from aqueous solution, simultaneously.     

Obtaining and characterization of catalytic materials from waste tires for the Fischer–Tropsch process

Journal of Material Cycles and Waste Management - In this contribution, the preparation of iron-based catalysts from waste tires is reported. Waste steel from disused tires was used as feedstock to...     

Degradation Study of Biobased Polyester–Polyurethane and its Nanocomposite Under Natural Soil Burial,UV Radiation and Hydrolytic-Salt Water Circumstances

The current study focuses on the development of a formulation of polyester polyurethane (PEPU) samples using castor oil (CO) modified polyester polyol and partially biobased aliphatic isocyanate. The CO modified polyester polyol was synthesized employing transesterification reaction between CO and diethylene glycol in the presence litharge (PbO) catalyst. Subsequently, the modification of CO was confirmed using proton nuclear magnetic resonance (¹HNMR) spectra analysis. In the next stage, the biobased polyester polyurethane nanocomposites (PEPUNC) were prepared by incorporating 3 wt% OMMT nanoclay within PEPU through in situ polymerization technique. The produced PEPU was confirmed by Fourier transform infrared spectroscopy (FTIR) and ¹HNMR spectra analysis. Further, the degradation properties of developed PEPU subjected to soil-burial, UV exposure and hydrolytic-salt water medium were noted by FTIR spectroscopy. Corresponding weight loss, mechanical measurements and morphological studies through scanning electron microscopy (SEM) analysis were studied. The results showed that the addition of OMMT nanoclay within the PEPU matrix produces significant improvement in the degradation rate which indicated the susceptibility of OMMT nanoclay to humidity upon exposure to soil burial. The produced microorganisms from the soil resulted in significant chemical and morphological changes in the entire structure of the PEPU. Additionally, the highest degradation and percentage of weight loss was observed under soil burial as compared to UV exposure and hydrolytic-salt water medium.