Sains Malaysiana 38(3): 295-304(2009)

Leachate Composition and Groundwater Pollution at Municipal Solid

Waste Landfill of Ibb City, Yemen

(Komposisis Larut Lesap Bahan Buangan dan Pencemaran Air Bawah

Tanah di Tapak Pelupusan Sisa Pepejal Bandar Ibb, Yemen)

Esmail Al Sabahi*, Abdul Rahim S, Wan Zuhairi W.Y. & Fores Alshaebi

Geology Programme, School of Environment and Natural Resource Sciences

Faculty of Science and Technology, Universiti Kebangsaan Malaysia

43600 Bangi Selangor, Malaysia

Fadhil Al Norzaily

Water and Environment Center, Sana'a University

Republic of Yemen

Received: 24 March 2008/Accepted: 17 October 2008

ABSTRACT

Compositions of landfill leachate and groundwater pollution were studied at Ibb landfill, which is located at Al-Sahool area, north of Ibb City, Yemen.  The leachate was sampled at three different locations at the landfill, i.e. at the landfill itself and at 15 and 20 m downstream of the landfill. Groundwater samples were collected from five boreholes to study the possible impact of leachate percolation into the groundwater. The leachate and groundwater samples were collected during wet season, due to the excessive generation of leachate during this season. The objective of this paper is to evaluate  the groundwater pollution due to the landfill leachate. The leachate and groundwater were physically and chemically characterised. The parameters measured were pH, temperature, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), fluoride (F), chloride (Cl), sulphate (SO₄), nitrites (NO₂), nitrates (NO₃), ammonia-N (NH₃-N), heavy metals (Pb, Zn, Ni, Cr, Cd dan Cu), major cations (Na, Mg, Ca, K and Fe) and biological parameters (COD and BOD₅).  The leachate at this landfill is most likely in methanogenic phase, based on the alkaline pH value recorded (pH=8.2). The results show that four out of  five boreholes are contaminated, where the concentration of physico-chemical parameters are above the standard acceptable levels which are required for drinking water adapted by Yemen's Ministry of Water and Environment (YMWE, 1999). Therefore, detailed study of the leachate and its effect to the groundwater in the study area is recommended.

Keywords: groundwater; heavy metals; Ibb landfill; pollution

ABSTRAK

Kajian tentang komposisi sisa larut lesap bahan buangan yang terhasil dari tapak pelupusan sisa pepejal dan pencemaran air bawah tanah telah dijalankan di tapak pelupusan sisa Ibb yang terletak di kawasan Al-Sahool, bahagian utara Bandar Ibb, Yemen.  Pensampelan sisa larut lesap bahan buangan ini dibuat pada tiga kawasan yang berasingan pada tapak pelupusan sisa tersebut iaitu di kawasan tapak pelupusan itu sendiri dan kawasan yang terletak sejauh 15 dan 20 meter ke hilir tapak pelupusan tersebut.  Pensampelan air bawah tanah di ambil dari lima lubang gerudi untuk mengkaji kemungkinan kemasukan sisa larut lesap ke dalam air bawah tanah tersebut.  Sampel sisa larut resap dan air bawah tanah hanya diambil pada musim hujan. Objektif kajian ini adalah untuk mengkaji pencemaran air bawah tanah oleh bahan larut lesap daripada tapak pelupusan. Sampel larut resap dan air bawah tanah ini dicirikan secara fizikal dan kimia. Antara parameter yang diukur ialah pH, suhu, kekonduksian arus elektrik (EC), jumlah pepejal terlarut (TDS), oksigen terlarut (DO), fluorida (F), klorida (CI), sulfat (SO₄), nitrit (NO₃), amonia-N (NH3-N), logam berat (Pb, Zn, Ni, Cr, Cd dan Cu), kation major (Na, Mg, Ca, K dan Fe) dan parameter biologi (COD dan BOD5).  Bahan larut lesap di tapak pelupusan ini terletak dalam kategori fasa metanogenik berdasarkan kepada nilai pH yang bersifat alkali yang direkodkan (pH=8.2). Keputusan menunjukkan bahawa empat daripada lima lubang gerudi telah tercemar dengan kepekatan parameter fizikal-kimia air adalah lebih tinggi daripada nilai piawai air yang selamat diminum yang telah ditetapkan oleh Kementerian Air dan Sekitaran Yemen. Oleh itu kajian terperinci terhadap bahan sisa larut lesap dan kesan pencemaran ke atas air permukaan dan air bawah tanah disyorkan.

Katakunci: Air bawah tanah; logam berat; tapak pelupusan Ibb

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*Corresponding author