Effect of Al3+, Ca2+, Cu2+ and Fe2+ on removal of Radium-226 from radium-contaminated soil using humic acid

Abstract

ABSTRACT

Effect of Al³⁺, Ca²⁺, Cu²⁺ and Fe²⁺ on the removal of radium-226 from radium-contaminated soil using humic acid extracted from a Malaysian peat soil was investigated using batch washing method. The concentration of Al³⁺, Ca²⁺, Cu²⁺ and Fe²⁺ ranged from 0 to 100 ppm. The radioactivity concentration of radium-226 was determined by gamma spectrometer. The removal of radium-226 was enhanced in the presence of Al³⁺ with concentration between 20 – 60 ppm. Meanwhile, higher concentration of 80 – 100 ppm did not lead to further increase in the removal of radium-226. The removal of radium-226 was decreased in the presence of Ca²⁺ and Cu²⁺. In the presence of Fe²⁺ with concentration between 20 – 60 ppm, decrease in the removal of radium-226 was also observed. Nevertheless, at concentration between 80 – 100 ppm, the presence of Fe²⁺ led to increase in the removal of radium-226.

Keywords: Al³⁺; Ca²⁺; Cu²⁺; Fe²⁺; Radium-226; Soil; Humic Acid 

ABSTRAK 

Kesan Al³⁺, Ca²⁺, Cu²⁺ dan Fe²⁺ ke atas penyingkiran radium-226 daripada tanih tercemar radium menggunakan asid humik yang diekstrak daripada tanih gambut Malaysia melalui kaedah pembasuhan berkelompok telah dikaji. Kepekatan Al³⁺, Ca²⁺, Cu²⁺ dan Fe²⁺ adalah dalam julat antara 0 sehingga 100 ppm. Kepekatan radioaktiviti radium-226 ditentukan menggunakan alat spektrometer gama. Penyingkiran radium-226 ditingkatkan dalam kehadiran Al³⁺ berkepekatan antara 20 – 60 ppm. Sementara itu, kepekatan yang lebih tinggi iaitu antara 80 – 100 ppm tidak lagi menyebabkan kenaikan dalam penyingkiran radium-226. Penyingkiran radium-226 menurun dalam kehadiran Ca²⁺ dan Cu²⁺. Dalam kehadiran Fe²⁺ berkepekatan antara 20 – 60 ppm, penurunan dalam penyingkiran radium-226 diperhatikan. Walau bagaimanapun, pada kepekatan antara 80 – 100 ppm, kehadiran Fe²⁺ menyebabkan penurunan dalam penyingkiran radium-226.