Enhancement of landfill daily cover performance by using mixture of local soil, pressmud and empty fruit bunch in minimizing the migration of heavy metals in landfill / Maheera Mohamad
Peningkatan kepekatan logam berat dalam larut lesap tapak pelupusan sisa pepejal adalah membimbangkan kerana ia merupakan bahan utama kepada terjejasnys kualiti kesihatan manusia dan persekitaran sekitarnya. Pengubahsuaian penutup tanah harian tapak pelupusan sisa pepejal adalah pilihan yang baik untuk mengurangkan pergerakan logam berat di dalam sel pelupusan sampah. Dalam kajian ini, sampel tanah tempatan kemudian dicampur dengan pressmud iaitu bahan buangan daripada proses pembuatan gula dan tandan kosong buah kelapa sawit (EFB) dengan peratusan berat yang berbeza. Seterusnya, eksperimen penjerapan dilakukan secara kajian kelompok untuk mengkaji keberkesanan campuran tanah-pressmud-EFB dalam menyingkirkan logam berat. Keberkesananya dibandingkan dengan penggunaan tanah, pressmud dan EFB secara individu. Pencirian bagi tanah dan juga campuran tanah-pressmud-EFB secara fizikokimia dan geoteknikal, seterusnya ujian luluhlarut dijalankan. Kaedah ujian luruhlarut termasuk ujian keseimbangan kelompok dan ujian turus tanah. Daripada kajian pencirian, terdapat beberapa penambahbaikkan sifat fizikokimia dan pencirian kejuruteraan bagi campuran berbanding dengan tanah sahaja. Campuran tanah-pressmud-EFB berkeupayaan menyingkirkan lebih daripada 59% sehingga 98.9% kandungan Cd, Cr, Cu, Fe, Mn, Ni and Zn penyingkiran logam berat daripada larutan. Sementara itu, kecekapan penyingkiran logam berat di dalam tanah adalah masing-masing daripada 1.6% sehingga 33.3% sahaja manakala pressmud pula menunjukkan daripada 78.4% sehingga 99.7% penyingkiran. EFB hanya menunjukkan 19.9% sehingga 56.2% penyingkiran. Kaedah respon balas permukaan (RSM) mengenai reka bentuk komposit pusat (CCD) telah digunakan untuk mengoptimumkan pembolehubah operasi terhadap keberkesanan setiap respon daripada segi kecekapan penyingkiran kepekatan awal dan masa tindak balas. Berdasarkan hasil ujikaji, 4.05 mg/L kepekatan awal dan 30 minit masa tindak balas diperlukan untuk penyingkiran untuk semua logam berat. Keputusan ujian turus yang berdasarkan kepada kajian pencirian, kecekapan penyingkiran dan penjerapan bahan campuran tanah-pressmud-EFB khususnya 50S:40P:10E adalah lebih sesuai dan mempunyai potensi yang baik untuk digunakan sebagai bahan penutup tanah harian untuk meminimakan penghijrahan logam berat dalam larut lesap di tapak pelupusan sisa pepejal.
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An increase of heavy metals concentration in landfill leachate is a concern as it is a major threat to human health and surrounding environment. Landfill daily soil cover amendment is a good option to reduce the mobility of heavy metals in the landfill cell. In this study, local soil samples were mixed with waste from sugar manufacturing process, pressmud and empty fruit bunch (EFB) of palm oil at different percentage of weight ratio. Then, batch adsorption experiments were performed to evaluate the effectiveness of soil mixtures in removing the heavy metals. Their performances were compared to the individual performance of the soil, pressmud and EFB. The physicochemical and geotechnical properties of the soil, pressmud, EFB and soil-pressmud-EFB mixtures characterization as well as leaching test were carried out. The leaching test method included batch equilibrium test and soil column test. From the characterization study, there were some improvements on the physicochemical and engineering properties of mixtures compared to soil alone. Batch equilibrium test showed that the soil-pressmud-EFB mixtures have the capability to remove more than 59% to 98.9% Cd, Cr, Cu, Fe, Mn, Ni and Zn metals from solution. Meanwhile, the removal efficiency of heavy metals from solution in the soil alone was ranged from 1.6% to 33.3%. Pressmud alone, however, showed 78.4% to 99.7% heavy metals removal while EFB indicated 19.9% to 56.2% removal. The response surface methodology (RSM) concerning Central Composite Design (CCD) was used to optimize the experimental condition in the removal of heavy metals. According to the results, initial concentration of 4.05 mg/L and 30 minutes contact time were required to effectively remove all heavy metals. Based on the characterization study, the removal efficiency and the column test, the soil-pressmud-EFB mixture particularly 50S:40P:10E was the most suitable combination and possessed great potential as daily cover to reduce heavy metals migration in landfill leachate.
Enhancement of landfill daily cover performance by using mixture of local soil, pressmud and empty fruit bunch in minimizing the migration of heavy metals in landfill / Maheera Mohamad
Enhancement of landfill daily cover performance by using mixture of local soil, pressmud and empty fruit bunch in minimizing the migration of heavy metals in landfill_Maheera Mohamad_A9_2018_MYMY