Bulletin of the Geological Society of Malaysia, Volume 51, June 2005, pp. 47 – 57

The retention capabilities of soils at Batang Berjuntai and Ampar Tenang as natural clay liners for landfill systems using leaching column test and selective sequential extraction analysis

NURITA RIDWAN, W.Z.W. YAACOB & ABDUL RAHIM SAMSUDIN

Geology Programme, School of Environmental Sciences and Natural Resources, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi

Abstract: Clay liners have the ability to interact chemically with leachate. If suitable clay liner can be identified, it can help to attenuate the migration of leachate to groundwater and surface water. In this study, leaching column tests were used to determine the retention capability of heavy metals for two types of soils collected adjacent to a landfill in Selangor. The active landfill sites chosen are Kg. Hang Tuah in Batang Berjuntai (HMS) and Ampar Tenang, Sepang (ARA) where the HMS samples are metasediment soil and ARA samples are river alluvium soil. Selective sequential extraction (SSE) was used to study the retention mechanisms of heavy metals in the soil columns obtained from leaching column test experiments. Acid digestion was later used to check the validity of the SSE results. Breakthrough curves for metasediment soil from Kg. Hang Tuah show good retention of heavy metal ions with relative concentration, C_e/C_o (10^-1– 10^-5) compared to river alluvium soil from Ampar Tenang with relative concentration, C_e/C_o (10^-1 -10^-4). This corresponds with the pH of the effluents and the pore fluid where the HMS samples are more alkali compared to ARA samples. Generally, HMS and ARA samples have same ranked order of buffering capacity; Cu:>Zn>Pb>Ni. The distribution of the heavy metals with soil constituents are ranked in the following phases: Exchangeable> Carbonates> Hydroxides> Residuals> Organics.

Abstrak: Pelapik lempung mempunyai keupayaan untuk bertindak secara kimia terhadap cecair larut lesap. Sekiranya pelapik lempung yang sesuai dapat dikenalpasti, ia dapat membantu bagi mengurangkan migrasi cecair larut lesap ke dalam air bawah tanah dan air permukaan. Dalam kajian ini, ujian kolum turasan telah digunakan untuk mengenalpasti keupayaan menahan logam-logam berat bagi dua jenis tanah yang telah diambil berdekatan tapak pelupusan sisa di Selangor. Tapak pelupusan sisa pepajal yang aktif yang dipilih ialah di Kg. Hang Tuah di Batang Berjuntai (HMS) dan di Ampar Tenang, Sepang (ARA) di mana sampel HMS merupakan tanah metasedimen dan ARA pula merupakan tanah aluvium sungai. Rangkaian pengestrakan terpilih (SSE) telah digunakan untuk mengkaji mekanisma menahan logam-logam berat di dalam kolum tanah yang diperolehi daripada eksperimen ujian kolum turasan. Pencernaan asid telah digunakan untuk memastikan kesahihan keputusan SSE. Pecahan lengkung-lengkung bagi tanah metasedimen dari Kg. Hang Tuah menunjukkan penahanan ion logam berat yang baik dengan konsentrasi relatif, C_e/C_o (10^-1-10^-5) berbanding tanah alluvium sungai dari Ampar Tenang dengan konsentrasi relatif, C_e/C_o (10^-1-10^-4). Ini selari dengan nilai pH efluen dan cecair liang yang menunjukkan sampel HMS lebih beralkali berbanding sampel ARA. Keseluruhannya, sampel HMS dan ARA mempunyai kedudukan susunan kapasiti menampan yang sama; Cu>Zn>Pb>Ni. Taburan logam-logam berat dengan juzuk tanah telah disusun seperti fasa berikut: Tukarganti > Karbonat > Hidroksida > Residual > Organik.

https://doi.org/10.7186/bgsm51200507