Kinetic studies of the sorption process of Pd(II) chloride complex ions from diluted aqua solutions using commercially available activated carbon

Abstract

The kinetics of Pd(II) chloride complex ion recovery from diluted aqueous solutions was investigated using commercially available activated carbon. For this purpose, several different parameters as the influence of temperature, mixing rate, amount of activated carbon applied as well as initial concentrations of Pd(II) chloride complex ions were analyzed. The obtained results showed that the rate of the process is controlled by the mass transfer from the solution to the surface of AC. Therefore, a significant impact of the mixing rate was observed. The activation energy of each step was determined and it is found to be 23.5 ± 1.3, 52.7 ± 5.5 and 22.8 ± 9.5 kJ/mol for adsorption, desorption and reaction of Pd(II) chloride complex transformation. It was shown that commercially available activated carbon, initially designed for gas purification, can be also used for metal ions removal during water purification as well as for precious metal recovery.

Recovery of Pd(II) Ions from Aqueous Solutions Using Activated Carbon Obtained in a Single-Stage Synthesis from Cherry Seeds

“…The sorption capacity of activated carbon can easily be tested with the use of noble metal ions as model systems and as a potential sorbent content [39]. Their high price is an economic basis for developing a technology for their recovery with the use of sensitized activated carbon.…”

Highly Selective Adsorption and Recovery of Palladium from Spent Catalyst Wastewater by 1,4,7,10-Tetraazacyclododecane-Modified Mesoporous Silica

“…However, their development remains in its infancy and is often accompanied by a long recovery period and difficulty in selecting excellent strains. The wet process has become the most promising to complete enrichment and recovery of precious metals. − In the wet process, according to different mechanisms, it can be divided into adsorption, − ion exchange, complexation–extraction, and precipitation, ,− all of which are effective recovery methods. , Among them, the application of the adsorption method is gradually increasing with the advantages of fast kinetics, high enrichment coefficient, and reduced waste accumulation. In addition, the adsorption method has the advantages of simple operation, wide functionalization, and easy material availability, making it more practical and effective than other methods.…”

“…To improve the selectivity of recovery, the adsorbent is often modified, such as combining substances containing specific complex groups with palladium. The carriers commonly used for metal adsorption and recovery are silica, , activated carbon, ,, carbon black, graphene oxide, carbon nanotubes, organic macromolecules, biomass, and other materials. − The characteristic complex groups for palladium contain amine, ,− amide, carboxyl, hydroxyl, and so on . However, there are still problems in precious metal recovery research, such as low recovery rates, poor selectivity, and poor regeneration effects.…”

“…In recent reports, Petrova et al used an N -(2-sulfoethyl) chitosan-based adsorbent to recover palladium from Pt­(IV)–Pd­(II) binary solution . Sharififard et al recovered palladium using commercially available activated carbon and biopolymer-modified activated carbon. ,, However, the wide use of these adsorbents in a strong acid medium or under the influence of multiple impurity ions is questionable in detecting whether the recovery efficiency and selectivity of palladium can meet the requirements. In short, the selective separation and high-efficiency recovery of Pd­(II) require continuous exploration of functional adsorbent materials and a better understanding of the theoretical recovery mechanism.…”