Kinetic Modelling of the Removal of Multiple Heavy Metallic Ions from Mine Waste by Natural Zeolite Sorption

Abstract

This study investigates the sorption of heavy metallic ions (HMIs), specifically lead (Pb 2+), copper (Cu 2+), iron (Fe 3+), nickel (Ni 2+) and zinc (Zn 2+), by natural zeolite (clinoptilolite). These HMIs are combined in single-, dual-, triple-, and multi-component systems. The batch mode experiments consist of a total initial concentration of 10 meq/L normality for all systems, acidified to a pH of 2 by concentrated nitric (HNO 3) acid. A zeolite dosage of 4 g per 100 mL of synthetic nitrate salt aqueous solution is applied, for a contact period of 5 to 180 min. Existing kinetic models on HMIs sorption are limited for multi-component system combinations. Therefore, this study conducts kinetic analysis by both reaction and diffusion models, to quantify the sorption process. The study concludes that the process correlates best with the pseudo-second-order (PSO) kinetic model. In the multi-component system combining all five HMIs, the initial sorption rate and theoretical equilibrium capacity are determined as 0.0033 meq/g•min and 0.1159 meq/g, respectively. This provides significant insight into the mechanisms associated with the sorption process, as well as contributing to the assessment of natural zeolite as a sorbent material in its application in industrial wastewater treatment.

An Innovative Dual-Column System for Heavy Metallic Ion Sorption by Natural Zeolite

“…The final total waste (TW2) effluent concentrations report very good removal for all ions except for Ni 2+ , with a removal of 48.97%. This removal trend is also consistent with the batch analyses conducted by Ciosek and Luk [32,33]. This is significant, as it proves that results from complex experimental batch studies, which are in high abundance, are useful in providing information on the sorption performance (i.e., removal efficiency, selectivity, and kinetics) in industrial applications where the process is run in a continuous flow-feeding configuration.…”

“…Due to the unique automated variable influent feeding rate and sampling technique proposed in this study, the usage rate and performance efficiency are very complex [28]. However, the major removal trend of Pb2+ >> Fe3+ > Cu2+ > Zn2+ >> Ni2+ is well-established and supports previous results [22,27,32,33,38,42,43], providing significant validation of this design.…”

“…Detailed analysis on the selected HMIs of this study was conducted by Ciosek and Luk [32,33] in batch-mode configuration, consisting of a synthetic nitrate salt solution at 10 meq/L total concentration, acidified to a pH of 2 by concentration HNO 3 acid, with a zeolite dosage of 4 g per 100-mL HMI solution. The aqueous solution is agitated within a contact period 180 min by means of a triple-eccentric drive orbital shaker operating at 400 r/min set to 22 • C. The five (5) HMIs were methodically combined in single-, dual-, triple-, and multi-component systems.…”

An innovative dual-column system for heavy metallic ion sorption by natural zeolite

“…The authors have conducted a four-phase research project, consisting of the analysis of: (1) the effects of preliminary parameters and operative conditions (particle size, sorbent-to-sorbate dosage, influent concentration, contact time, set-temperature, heat pre-treatment), (2) heavy metallic ions component system combinations and selectivity order [32], (3) kinetic modelling trends [33], and finally in this current study, (4) the design of a packed fixed-bed, dual-column sorption system. The first three phases are conducted in batch mode, to which reveal a key trend among the HMIs selected as lead (Pb 2+ ) >> iron (Fe 3+ ) > copper (Cu 2+ ) > zinc (Zn 2+ ) > nickel (Ni 2+ ).…”

Effects of Operation Parameters on Heavy Metallic Ion Removal from Mine Waste by Natural Zeolite

“…The authors have designed a four-phase research project, which investigates: (1) the effects of preliminary parameters and operative conditions (particle size, sorbent-to-sorbate dosage, influent concentration, contact time, set-temperature, and heat pre-treatment), (2) HMIs component system combinations and selectivity order with a focus on its effects on the removal of lead (Pb 2+ ) [22], (3) kinetic modelling trends [23], and (4) the design of a packed, fixed-bed, dual-column sorption treatment system [24].…”