Objektif kajian ini adalah untuk mengkaji kesan suhu and pH terhadap enapcemar bebutir dan enapcemar flokulen dalam pencernaan aerob kumbahan kilang kelapa sawit (POME). Prestasi enapcemar bebutir dan floccular telah dinilai dengan merujuk kepada kadar pengikiran keperluan oksigen kimia (COD) dan kadar pengambilan oksigen spesifik (SOUR) masing-masing. Kedua-dua enapcemar mencapai kadar pengikiran COD yang tertinggi pada suhu 300C. Enapcemar bebutir mempunyai kadar pengikiran COD yang lebih tinggi daripada enapcemar flokulen pada suhu 200C dan 300C, tetapi enapcemar bebutir menghadapi masalah dalam mengekalkan strukturnya dan mengalami lisis dalam suhu yang tinggi. Kadar pengikiran COD bagi enapcemar bebutir menurun dengan banyak apabila suhu meningkat sampai 400C. Enapcemar flokulen mempunyai kelebihan untuk berfungsi dalam suhu yang tinggi dan mempunyai kadar pengikiran COD yang lebih tinggi daripada enapcemar bebutir pada suhu 400C. Ini menunjukkan enapcemar flokulen lebih sesuai digunakan dalam pencernaan aerob POME dalam keadaan yang panas manakala enapcemar bebutir lebih sesuai diguna dalam keadaan suhu yang normal. SOUR bagi enapcemar bebutir sangat rendah pada suhu 200C dan semakin meningkat dalam suhu tinggi. Kajian tersebut menunjukkan SOUR bagi kedua-dua enapcemar tidak setaraf dengan kadar pengikiran COD mereka. Ini disebabkan perubahan suhu dan pH akan mengubah struktur dan fungsi pencernaan enapcemar, akibatnya jumlah oksigen yang diperlukan untuk pengoksidaan substrat juga berbeza mengikut perubahan strukturnya. Pada suhu 400C, enapcemar bebutir mencapai SOUR yang tinggi namun pada masa yang sama mempunyai kadar pengikiran COD yang rendah berbanding dengan enapcemar flokulen. Perubahan skruktur enapcemar bebutir dalam suhu tunggi menjejaskan proses pencernaan dan menyebabkan enapcemar bebutir mengambil lebih banyak oksigen tetapi masih kurang substrat yang dioksidakan. pH memainkan peranan yang penting dalam mempengaruhi prestasi kedua-dua enapcemar dalam pencernaan aerob POME kerana enapcemar hanya berfungsi dengan bagus dalam julat pH yang memihak kepada pemakanan, pembiakan dan kehidupan mereka. pH optimum bagi kedua-dua enapcemar adalah pH 7. Enapcemar flokulen lebih lemah dalam menghadapi perubahan pH terutamanya bertukar kepada medium beralkali. Kadar pengikiran COD dan SOUR bagi enapcemar flokulen menurun apabila pH medium meningkat sampai pH 9.
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The objective of the present study is to investigate the effect of temperature and pH on aerobic granular and floccular sludge in aerobic treatment of POME. The performance of the granular and floccular sludge was assessed by measuring chemical oxygen demand (COD) removal efficiency and specific oxygen uptake rate (SOUR). Both granular and floccular sludge had the highest COD removal efficiency at temperature 300C. Granular sludge had higher COD removal efficiency than floccular sludge at temperature 200C and 300C, but granular sludge tend to denaturize and lyse more easily at high temperature. The COD removal efficiency of granular sludge has dropped significantly when the temperature increased to 400C. Floccular sludge was more adaptable in high temperature and had higher COD removal efficiency than granular sludge at 400C. This indicates that floccular sludge is more suitable to be used for treating POME in thermophilic condition whereas granular sludge is more suitable in mesophilic condition. The SOUR of granular sludge was low at 200C and increased gradually when the temperature of the medium increased. From this study, it was found that the SOUR of both granular and floccular sludge were not tally with their COD removal efficiency because the variation of temperature and pH had altered the structure and biodegradable function of both granular and floccular sludge, consequently the amount of oxygen required for oxidation of a substrate was also different. At 400C, granular sludge had higher SOUR but with lower COD removal efficiency as compared to floccular sludge. The changed of structure of granular sludge at high temperature affected its biodegradable function and subsequently caused the granular sludge to consume more oxygen but oxidized less amount of substrate. The pH medium plays an important role in affecting the performance of both granular and floccular sludge in aerobic treatment of POME, because activated sludge prevail in certain range of pH that favor the nutrition, reproduction and survival. This study shows that the optimum pH medium for both granular and floccular sludge was pH 7. Floccular sludge had the lower ability to withstand the sudden changed of pH especially changed to alkaline medium. The COD removal efficiency and SOUR had reduced significant when the medium pH increased to pH 9.
Comparison between the effect of temperature and pH on aerobic granular and floccular sludge in aerobic treatment of pome / Leow Wei Jien