Bulletin of the Geological Society of Malaysia, Volume 46, May 2003, pp. 409 – 413

Kajian perlakuan larut lesap Cu, Cr, Ni, Pb dan Zn dalam tanah laterit dari Ranau, Sabah

Study on leaching behaviour of Cu, Cr, Ni, Pb, and Zn in lateritic soil from Ranau, Sabah

BABA MUSTA¹, HAMZAH MOHAMAD², MOHAMAD MD. TAN², ANIZAN ISAHAK² DAN OSAMA TWAIQ²

¹Sekolah Sains dan Teknologi, Universiti Malaysia Sabah, 88999 Kota Kinabalu, Sabah, Malaysia

²Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia

Abstrak: Perlakuan larut resap logam-logam berat iaitu Cu, Cr, Ni, Pb, dan Zn dalam tanah laterit dikaji dengan menggunakan ujian larut lesap. Sampel laterit dilarut lesapkan dengan asid pH 3.2 pada tekanan 15 psi. Kandungan kelimpahan logam-Iogam berat dalam laterit dan cecair larut resapan dianalisis menggunakan kaedah spectrometer serapan atom (AAS). Keputusan analisis profil migrasi bagi logam-logam Ni, Cr, Cu, Pb dan Zn menunjukkan nilai yang lebih tinggi pada bahagian bawah profil laterit. Ini menunjukkan ada berlakunya migrasi atau larut lesap logam-Iogam daripada bahagian atas kebahagian bawah. Ini juga disokong oleh analisis kandungan kepekatan cecair larut resap yang mana menunjukkan kandungan Cr dan Ni yang tinggi. Profil migrasi bagi Cu, Pb, dan Zn pula didapati sangat rendah kandungannya dalam cecair larut lesap kerana nilai dalam tanah lateritik asal yang sangat rendah. Analisis struktur mikro dalam tanah asal laterit menunjukkan kehadiran mineral bersudut yang kebanyakannya terdiri daripada goethit, hematit dan gibsit. Mineral-mineral tersebut didapati mengalami proses pelarutan dan jelas ditunjukkan oleh struktur permukaan yang berubah menjadi sub-bulat oleh mikrograf elektron pengimbas (SEM).

Abstract: The leaching behaviour of heavy metals namely Cu, Cr, Ni, Pb and Zn in lateritic soil were studied using the leaching test. The lateritic soil were leached with acid pH 3.2 at the pressure of 15 psi. The concentration of heavy metals in lateritic soil and leachate were analysed using Atomic Absorption Spectrometer (AAS) method. The result of migration profiles analysis for Ni, Cr, Cu, Pb and Zn metals shows the heavy metals concentration was high in the bottom part. This indicates the migration or leaching process of heavy metals from the top to the bottom part. This is also supported by results from the analysis of leachate sample, which indicates the high concentrations of Cr and Ni. The migration profile of Cu, Pb, and Zn are very low in leachate due to the very low concentration in the original lateritic soil. The micro structural analysis on lateritic soil shows the appearance of angular minerals mainly goethite, hematite and gibbsite. These minerals are found to be dissolved and clearly seen with the formation of sub-angular on the surface structure in the scanning electron micrographs (SEM).

https://doi.org/10.7186/bgsm46200366