Influence of Salinity on the Removal of Ni and Zn by Phosphate-Intercalated Nano Montmorillonite (PINM)

Abstract

The salinity influence on the adsorptions of Ni and Zn onto phosphate-intercalated nano montmorillonite (PINM) were investigated. Single adsorption isotherm models fitted the single adsorption data well. The adsorption capacity of Ni was higher than that of Zn onto PINM at different salinities. The single adsorption parameters from Langmuir model (QmL and bL) were compared with the binary adsorption ( and ). The of Zn was lower than that of Ni. The simultaneous presence of Ni and Zn decreased the adsorption capacities. The single and binary adsorptions onto PINM were affected by the salinity. The competitive Langmuir model (CLM), P-factor, Murali and Aylmore (MA) models, and ideal adsorbed solution theory (IAST) were satisfactory in predicting the binary adsorption data; the CLM showed the best fitting results. Our results showed that the PINM can be used as an active Ni and Zn adsorbent for a permeable reactive barrier (PRB) in the remediation of saline groundwater.

Adsorption Kinetics of Cadmium and Lead by Biochars in Single- and Bisolute Brackish Water Systems

“…Figure b shows the Cd­(II) removal onto AC and different biochars in both systems (single- and bisolute), with AC exhibiting the highest adsorption in both solute systems at different salinity concentrations. The adsorption of Cd­(II) by AC dropped from 0.47 mg/g (single-solute) to 0.44 mg/g (bisolute) at 5 ppt salinity, and the amount of Cd­(II) adsorbed onto AC fell further in both systems (single- and bisolute) at 15 and 25 ppt salinities, which can be linked to the increased hindrance and competition of cations–anions from salt ions and the presence of Cd­(II) in the solution . It is interesting to note that all adsorbents followed a similar pattern of adsorption in both solute systems, in the order AC > BB > MB > PSB.…”

“…The adsorption of Cd(II) by AC dropped from 0.47 mg/g (single-solute) to 0.44 mg/g (bisolute) at 5 ppt salinity, and the amount of Cd(II) adsorbed onto AC fell further in both systems (single-and bisolute) at 15 and 25 ppt salinities, which can be linked to the increased hindrance and competition of cations−anions from salt ions and the presence of Cd(II) in the solution. 75 It is interesting to note that all adsorbents followed a similar pattern of adsorption in both solute systems, in the order AC > BB > MB > PSB. The least performing biochar for the Cd(II) removal in a bisolute system at 25 ppt salinity was PSB (adsorption efficiency 0.17 mg/g) followed by MB (0.19 mg/ g).…”

Salinity-Induced Changes in Heavy Metal Behavior and Mobility in Semi-Arid Coastal Aquifers: A Comprehensive Review

“…The concentration in these aquifers saw an increase in concentration irrespective of the source of Ni, which is from mica dissolution (NW-C, India), industrial, mining wastewater in LB, China, and wastewater effluents in MA, Tunisia. Such increases are mainly due to the absorption nature of Ni clay minerals experimentally explained by [140], where desorption was found higher with increasing salinity by 30% owing to competition between the metals and cations in seawater solution by the limited cation exchange sites on clay minerals [141,142].…”