Adsorption from Brazilian soils of Cu(II) and Cd(II) using cattle manure vermicompost

• Published in: International journal of environmental studies Vol. 68; no. 5; pp. 719 - 736
• Main Authors: Jordão, C.P, Pereira, W.L, Carari, D.M, Fernandes, R.B.A, De Almeida, R.M, Fontes, M.P.F
• Format: Journal Article
• Language: English
• Published: Colchester Routledge 01.10.2011; Taylor & Francis
• Subjects: adsorption; Animal, plant and microbial ecology; Applied ecology; aqueous solutions; Biological and medical sciences; Brazilian soil; Cadmium; cattle manure; Conservation, protection and management of environment and wildlife; Copper; desorption; Ecotoxicology, biological effects of pollution; energy; Fundamental and applied biological sciences. Psychology; General aspects; heavy metals; Isotherm; Oxisols; sorption isotherms; Vermicompost; vermicomposts; South America; Brazil; America; Vermicompost; Cadmium; Pollutant; Brazilian soil; Adsorption; Isotherm; Copper; Cattle manure; Environmental management; Heavy metal
• ISSN: 1029-0400; 0020-7233; 1029-0400
• DOI: 10.1080/00207233.2011.587953

The potential of cattle manure vermicompost and Brazilian soils (whole soils and soils incubated with vermicompost) was assessed for adsorption of heavy metals such as Cu(II) and Cd(II) from aqueous solutions. Experimental data have been fitted to Langmuir and Freundlich isotherms to obtain the characteristic parameters of each model, with R² values from 0.89 to 0.99. Based on the maximum adsorption capacity obtained from the Langmuir isotherm the affinity of the studied metals for the vermicompost and soils have been established as Cu(II) > Cd(II). The values of the separation factor, RL, which has been used to predict affinity between adsorbate and adsorbent were between zero and 1, indicating that sorption was very favourable for Cu(II) and Cd(II) in synthetic solution. Addition of vermicompost to soils resulted in higher distribution coefficient, Kd, as compared with whole soils. The thermodynamic parameter, the Gibbs energy changes, was calculated for each system and the negative values obtained confirm that the adsorption processes are spontaneous. The ΔG° values for the substrates were between −2.630±1.41 kJ mol⁻¹ and −13.700±1.250 kJ mol⁻¹. Adsorption tests from multimetal systems confirm the affinity order obtained in the individual metal tests. The adsorption capacity for Cu(II) measured in individual tests is not reduced by the presence of Cd(II). There is also desorption of Cu(II) and Cd(II) previously bound to vermicompost, whole soils and soils incubated with vermicompost by DTPA. The experiment indicates the importance of cattle manure vermicompost and oxisol amended with vermicompost in relation to Cu(II) and Cd(II) adsorption from aqueous solution.