Supported liquid membrane extraction of nickel using stable composite SPEEK/PVDF support impregnated with a sustainable liquid membrane

Removal of nickel ions from industrial wastewater using tms-EDTA-functionalized Ti3C2Tx: Experimental and statistical physics modeling

This study investigates the surface modification of Ti3C2Tx MXene using tms-EDTA (EDTA@MXene) to develop an efficient adsorbent for divalent heavy metal cations, such as Cd²⁺, Cu²⁺, Ni²⁺, Pb²⁺, and Zn²⁺, from contaminated water. EDTA@MXene showed significantly enhanced adsorption capacities for these ions compared to pristine MXene. Using nickel ion (Ni²⁺) as a model adsorbate, EDTA@MXene demonstrated remarkable removal efficiency, reaching a maximum adsorption capacity of 249.5 mg/g as compared to the 61.4 mg/g of pristine MXene with fast kinetics and attaining equilibrium within 30 min. The results indicated that Ni²⁺ adsorption followed a pseudo-second-order kinetic model, with equilibrium data fitting both Langmuir and Freundlich isotherm models. As the classical adsorption models remained inconclusive on the underlying adsorption mechanisms, advanced statistical physics models were subsequently applied for deeper investigation. The findings revealed that Ni²⁺ ions adsorbed onto the surface in a non-parallel orientation. The adsorption process was reversible, endothermic, and driven mainly by physical interactions, with higher temperatures favoring greater adsorption capacity. EDTA@MXene demonstrated excellent reusability, maintaining high (>80 %) regeneration efficiency after five regeneration cycles. It also exhibited a high adsorption capacity for Ni²⁺ ions from nickel electroplating wastewater, highlighting its potential for real application in the treatment of metal-contaminated industrial wastewater.

Recovery of copper and silver from industrial e-waste leached solutions using sustainable liquid membrane technology: a review

Waste electrical and electronic equipment or e-waste has recently emerged as a significant global concern. This waste contains various valuable metals, and via recycling, it could become a sustainable resource of metals (viz. copper, silver, gold, and others) while reducing reliance on virgin mining. Copper and silver with their superior electrical and thermal conductivity have been reviewed due to their high demand. Recovering these metals will be beneficial to attain the current needs. Liquid membrane technology has appeared as a viable option for treating e-waste from various industries as a simultaneous extraction and stripping process. It also includes extensive research on biotechnology, chemical and pharmaceutical, environmental engineering, pulp and paper, textile, food processing, and wastewater treatment. The success of this process depends more on the selection of organic and stripping phases. In this review, the use of liquid membrane technology in treating/recovering copper and silver from industrial e-waste leached solutions was highlighted. It also assembles critical information on the organic phase (carrier and diluent) and stripping phase in liquid membrane formulation for selective copper and silver. In addition, the utilization of green diluent, ionic liquids, and synergist carrier was also included since it gained prominence attention latterly. The future prospects and challenges of this technology were also discussed to ensure the industrialization of technology. Herein, a potential process flowchart for the valorization of e-waste is also proposed.

Experimental design and RSM on the recovery of Ni (II) ions by ELM using TX-100 as a biodegradable surfactant

The present work deals with the extraction and pre-concentration of nickel (II) ions using emulsified liquid membrane (ELM) in the presence of di- (2-ethylhexyl) phosphoric acid (D2EHPA) as an extractant. The emulsion stability was achieved by the biodegradable surfactants Triton X-100 addition diluted in kerosene. Influence of operating conditions that affect ELM performance were investigated. A comparative study between the optimization parameters of this process was carried out both experimentally and with the Response Surface Methodology (RSM), in accordance with the Box-Behnken matrix. The following parameters were investegated: D2EHPA / Triton X-100 ratio between 0.5 and 3.5, initial concentration of the feed phase between 200 and 500 ppm and pH of the feed phase from 2.5-10. The transport of Ni (II) ions was evaluated according to the extraction yield as an analytical response and the optimal conditions were determined. It was found that the calculated values being in good agreement with experimental data that under the optimized conditions ([Ni] = 350 ppm, Vagitation = 200 rpm, t = 20 min and pH = 6.6), Ni (II) ions extraction was recorded more than 94% of efficiency.

Mg17Al12 phase in magnesium alloy waste facilitating the Ni2+ reduction in nickel plating wastewater

A process for recycling Ni²⁺ in Ni-plating wastewater was investigated. This study employed Mg alloy flash waste to reduce the Ni²⁺ in the wastewater into metallic Ni. Fine second-phase Mg₁₇Al₁₂ in a network is the critical point for promoting the reduction reaction of Ni²⁺. The microstructures of the Mg alloy flash scrap and the die-cast Mg alloy scrap waste fulfilled the requirement. The Mg₁₇Al₁₂ is like a catalyst for the quick reduction of the Ni²⁺ ions into pure Ni metal. Contrarily, pure Mg (not containing Mg₁₇Al₁₂ particles) and gravity-cast AZ91D Mg alloy (having coarse Mg₁₇Al₁₂ particles) were not suitable for being used for the Ni²⁺ wastewater treatment. Based on the above results and discussion, using the Mg alloy flash scrap waste for treating the laboratory-made Ni²⁺-containing wastewater, the wastewater initially with ∼5600 ppm of Ni²⁺ ions could be reduced to ∼20 ppm in 2 h. When applying the Mg alloy flash scrap for the Ni plating wastewater from industry, the concentration of Ni²⁺ was able to be reduced from ∼16,670 ppm to ∼1434 ppm in 10 min for the wastewater at 90 °C.