Adsorption of Cd(II) by rhizosphere and non-rhizosphere soil originating from mulberry field under laboratory condition

Abstract

In this study, the adsorption behavior of Cd ions by rhizosphere soil (RS) and non-rhizosphere soil (NS) originated from mulberry field was investigated. The Langmuir, Freundlich and the Dubinin-Radushkevich (D-R) equations were used to evaluate the type and efficiency of Cd adsorption. The RS was characterized by lower pH but the higher content of soil organic matter and cation exchange capacity (CEC) as compared to NS. Also, the maximum adsorption of Cd for RS (5.87 mg/g) was slightly bigger than that for NS (5.36 mg/g). In Freundlich isotherm, the K of the adsorption of Cd to surface of the RS components was higher than that of the NS, indicating stronger attraction between Cd and components of the RS. According to the D-R model, the adsorption of Cd by both soils was dominated by ion exchange phenomena. These results indicated that mulberry roots modified physical and chemical properties of the RS under field conditions, which also affected the Cd sorption efficiency by soil components during laboratory experiments. Current knowledge of the Cd sorption processes in the rhizosphere of mulberry may be important if these trees are planted for use in phytoremediation of Cd contaminated soils.

Physiological background of the remarkably high Cd2+ tolerance of the Aspergillus fumigatus Af293 strain

“…A number of fungi have an outstandingly high biosorption capacity that can be exploited to remove polluting metal ions (including Cd 2+ ) from wastewater or even to biomine valuable transition metals . In addition to direct biosorption by cell wall biopolymers, other extracellular matrices (“extracellular polymeric substances”) and the formation of metal‐oxalate precipitate on the cell wall contribute to their good biosorption potential .…”

“…Moreover, phosphate fertilizers may also have a high cadmium content; in addition to atmospheric deposition and water irrigation, the use of phosphate fertilizers is among the most important factors leading to increased cadmium concentrations in agricultural fields . Several approaches (from physical or chemical solutions to phytoremediation) have been developed to remove cadmium from soil or waste water , and techniques based on biosorption by microbes are also being intensively investigated .…”

The Effects of Different Lead Pollution Levels on Soil Microbial Quantities and Metabolic Function with/without Salix integra Thunb. Planting

“…It partly removed cations (Na + , K + , Ca 2+ , Ca2+, etc.) from the soil solution that led to the increase of CEC [60,61]. However, the CEC was decreased in the HT, which may be related to the balance of soil properties to the higher Pb pollution.…”

A comprehensive study on removal of cadmium from aqueous solution by using mesoporous SBA-15 functionalized by 1,5-diphenyl carbazide: experimental design, kinetic, thermodynamic, and isotherm aspects

“…The experimental data are analyzed by Langmuir, Freundlich [77], and D-R models. In the Langmuir isotherm, it is assumed that monolayer sorption occurs and the sorbent surface has a finite number of sorption sites with uniform energy [78], which is computed by (9). C e q e = 1…”

“…where C 0 and b denote Cd concentration (mg/L) and the Langmuir constant (L/mg), respectively. The following definition is given concerning the R L value and the favorability of the process [78]:…”