Influence of organic and inorganic amendments on cadmium sorption in a calcareous soil

• Published in: Main group metal chemistry 2016-12, Vol.39 (5), p.195-207
• Main Authors: Saffari, Mahboub, Saffari, Vahid Reza, Marashi Aliabadi, Maryam, Haghighi, Mojtaba Jafari, Moazallahi, Masomeh
• Format: Article
• Language: English
• Subjects: amendments; cadmium; calcareous soil; Kinetic equations; Mathematical analysis; Soil pollution; Soils; Sorption
• ISSN: 0792-1241; 2191-0219
• DOI: 10.1515/mgmc-2016-0028

A laboratory experiment was conducted to determine the benefits of some soil organic and inorganic amendments on cadmium (Cd) sorption capacity in non-polluted calcareous soil. The non-polluted soil was separately incubated with organic [municipal solid waste compost (MSWC), rice husk biochars prepared at 300°C (B300) and 600°C (B600)] and inorganic amendments (coal fly ash, CFA), zero valent iron (Fe ), and zero valent manganese (Mn ) at 2% and 5% (W/W) for 90 days at 25°C. After incubation, sorption kinetics and sorption isotherms of Cd were determined using batch experiments. Results show that the adjustments enhanced the sorption capacity of soil for Cd, as indicated by generally higher K and 1/n values (constants of Freundlich equation) and distribution coefficients (K ) compared with the control. The increase of Cd sorption in the soils with different amendments followed the sequence Mn >Fe >B600>CFA>MSWC>B300. Among the sorption isotherms and kinetic equations, the linear forms of Freundlich and simple Elovich equations yielded good prediction of Cd sorption, respectively. Generally, all amendments improved and increased Cd sorption rate. Given that Mn treatment had the highest impact on increasing Cd sorption capacity, it can thus be recommended in the immobilization of Cd from polluted soil.