Effects of Temperature on Aerobic Treatment of Anaerobically Digested Palm Oil Mill Effluent (POME)
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- 作者：Yi Jing Chan ; Mei Fong Chong ; Chung Lim Law
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2010
- 出版时间：August 4, 2010
- 年：2010
- 卷：49
- 期：15
- 页码：7093-7101
- 全文大小：239K
- 年卷期：v.49,no.15(August 4, 2010)
- ISSN：1520-5045
文摘
Aerobic treatment of wastewater under thermophilic conditions has received growing interest in recent years. Because of the high discharge temperature (75 to 85 °C) of palm oil mill effluent (POME), it would be more economical if POME were treated thermophilically, as then cooling facilities prior to biological treatment can be eliminated. In the present investigation, the feasibility of thermophilic aerobic biological treatment as a suitable post-treatment system for anaerobically treated POME was examined. Also, the effects of temperature on the treated effluent quality were investigated by using sequencing batch reactors (SBRs) under mesophilic (28 °C) and thermophilic (45, 50, and 55 °C) conditions. The average total COD (TCOD) removal efficiencies varied from 55 to 98% at organic loading rates (OLR) of 2.6 to 4.5 kg COD/m3·day, dissolved oxygen (DO) concentrations of 2.9−4.5 mg/L, and mixed-liquor suspended solids (MLSS) concentrations of 22500−24200 mg/L. The results show that the thermophilic aerobic treatment was capable of achieving promising treatment efficiencies in terms of TCOD and biochemical oxygen demand (BOD) removals, which exceeded 72% and 76%, respectively, at an OLR of 2.8 ± 0.3 kg COD/m3·day. The thermophilic sludge also showed good settling characteristics, as reflected by the low sludge volume index (SVI) values (<100). Nevertheless, aerobic treatment at mesophilic conditions produced better results as compared to the treatment at thermophilic conditions. The highest effluent quality was obtained under mesophilic conditions (28 °C), while the SBR operated at 55 °C produced the poorest effluent quality. The effluents treated under the thermophilic conditions were more turbid with the presence of higher total suspended solids (TSS), due to a lower capability to effectively retain the influent particles by the sludge. In the practice of minimum capital and operating costs, the encouraging results from this study propose that the thermophilic aerobic system can be integrated with a thermophilic anaerobic system for the treatment of POME.