Iron nanoparticles prepared from South African acid mine drainage for the treatment of methylene blue in wastewater.

In this study, three acid mine drainage (AMD) sources were investigated as potential sources of iron for the synthesis of iron nanoparticles using green tea extract (an environmentally friendly reductant) or sodium borohydride (a chemical reductant). Electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), oxidation-reduction potential (ORP), ion chromatography (IC), and inductively coupled plasma-mass spectroscopy (ICP-MS) techniques were used to characterize the AMD, and the most suitable AMD sample was selected based on availability. Additionally, three tea extracts were characterized using ferric-reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picryl-hydrazine-hydrate (DPPH), and the most suitable environmentally friendly reductant was selected based on the highest FRAP (1152 µmol FeII/g) and DPPH (71%) values.

Artificial neural network and response surface methodology for optimization of corrosion inhibition of mild steel in 1 M HCl by peel extract.

Banana () peel extract (BPE) was used as an environmentally benign corrosion inhibitor for mild steel in 1.0 M HCl. The efficiency of BPE was assessed by monitoring the pH of HCl solution and the quantity of hydrogen gas evolved during the reaction, using gasometric and thermometric methods.

Correction to "Kinetics, Thermodynamics, and Mechanism of Cu(II) Ion Sorption by Biogenic Iron Precipitate: Using the Lens of Wastewater Treatment to Diagnose a Typical Biohydrometallurgical Problem".

[This corrects the article DOI: 10.1021/acsomega.1c03855.

Kinetics, Thermodynamics, and Mechanism of Cu(II) Ion Sorption by Biogenic Iron Precipitate: Using the Lens of Wastewater Treatment to Diagnose a Typical Biohydrometallurgical Problem.

The feasibility of improving typical biohydrometallurgical operation to minimize copper losses was investigated by the use of biogenic iron precipitate for the uptake of Cu(II) ions from aqueous solutions. The iron precipitate was obtained from mineral sulfide bioleaching and characterized using SEM/EDS, XRD, FTIR, BET, TGA, and pH analyses. The results show that the precipitate is highly heterogeneous and that Cu(II) ion adsorption can be described by both Freundlich and Langmuir adsorption isotherms, with a maximum adsorption capacity of 7.

Isolation and characterization of nanocrystalline cellulose from cocoa pod husk (CPH) biomass wastes.

In this paper, cellulose nanocrystals (CNCs) were isolated from the cellulose extracted from cocoa pod husk waste, followed by characterization using XRD, FT-IR, TGA, SEM and TEM to determine its crystallinity, structural properties, thermal characteristics, morphology and dimensions respectively. The result revealed that the cocoa pod husk amorphous segments containing hemicelluloses and lignin were extensively removed with increasing chemical treatments leading to increased purity, crystallinity index and thermal stability of the extracted materials. The diameter, length and crystallinity index of the CNC isolated from the CPH are 10-60 nm, 41-155 nm and 67.

Optimization of process variables for acetoin production in a bioreactor using Taguchi orthogonal array design.

Microbial production of acetoin is eco-friendly and inexpensive when compared with its synthetic methods of production. In the present findings, bioproduction of acetoin in a typical bioreactor was discussed with a view to ascertain the seemingly comparative advantage of bioreactor system over shake flask, and more importantly, to confirm that corn steep liquor can indeed adequately be used as a replacement for other organic nitrogen sources. Taguchi design was statistically used to optimized the fermentation process which resulted in a 3-fold increase in molar yield (83%) corresponding to a six-fold increase in acetoin concentration (63.

Charge transfer between biogenic jarosite derived Feand TiO enhances visible light photocatalytic activity of TiO.

In this work, we have shown that mining waste derived Fe can be used to enhance the photocatalytic activity of TiO. This will allow us to harness a waste product from the mines, and utilize it to enhance TiO photocatalytic waste water treatment efficiency. An organic linker mediated route was utilized to create a composite of TiO and biogenic jarosite.

Synthesis of zeolite A from coal fly ash using ultrasonic treatment--A replacement for fusion step.

The synthesis of zeolites from fly ash has become an increasingly promising remedy to the crisis of coal fly ash production and disposal in South Africa. In recent studies, South African fly ash was proven to be a suitable feedstock for the synthesis of essential industrially used zeolite A. However, the process involves a costly energy intensive step whereby fly ash is fused at high temperatures, which may make the process economically unattractive on a large scale.

Distributional Fate of Elements during the Synthesis of Zeolites from South African Coal Fly Ash.

The synthesis of zeolites from South African coal fly ash has been deemed a viable solution to the growing economical strain caused by the disposal of ash in the country. Two synthesis routes have been studied thus far namely the 2-step method and the fusion assisted process. Fly ash contains several elements originating from coal which is incorporated in the ash during combustion.

Synthesis of Zeolites Na-P1 from South African Coal Fly Ash: Effect of Impeller Design and Agitation.

South African fly ash has been shown to be a useful feedstock for the synthesis of some zeolites. The present study focuses on the effect of impeller design and agitation rates on the synthesis of zeolite Na-P1 which are critical to the commercialization of this product. The effects of three impeller designs (4-flat blade, Anchor and Archimedes screw impellers) and three agitation speeds (150, 200 and 300 rpm) were investigated using a modified previously reported synthesis conditions; 48 hours of ageing at 47 °C and static hydrothermal treatment at 140 °C for 48 hours.

Waste Minimization Protocols for the Process of Synthesizing Zeolites from South African Coal Fly Ash.

Production of a high value zeolite from fly ash has been shown to be an avenue for the utilization of South African fly ash which presently constitutes a huge disposal problem. The synthesis of zeolites Na-P1 and analcime on a micro-scale has been successful and preliminary investigation shows that scale-up synthesis is promising. However, the post-synthesis supernatant waste generated contains high levels of NaOH that may constitute a secondary disposal problem.