Article 2 Availability 2 Bentonite 2 Biochemistry 2 Copper 2 Copper bioavailability 2 Copper speciations 2 Copper-contaminated 2 Exchangeable fraction 2 Extraction 2 Heavy Metals 2 Heavy metals 2 Metal speciation 2 Metals 2 Minerals 2 Pollution 2 Remediation 2 Selective sequential extractions 2 Sequential Selective Extraction Sequential selective extractions 2 Sodium 2 Sodium bentonite 2 Soil Pollution 2 Soil pollution 2 Soils 2 bentonite 2 bioavailability 2 bioremediation 2 clay 2 clay soil 2