کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
582530 | 1453164 | 2009 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Application of rhamnolipid and surfactin for enhanced diesel biodegradation-Effects of pH and ammonium addition
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بهداشت و امنیت شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
This study investigated the effects of pH and ammonium concentrations on the potential application of two biosurfactants, surfactin (SF) and rhamnolipid (RL), for enhanced diesel biodegradation with a series of bench-scale experiments. In general, compared to the experiments without biosurfactant addition, adding RL or SF to diesel-water systems at concentrations above their critical micelle concentration (CMC) values benefited diesel emulsification, and therefore enhanced diesel biodegradation. The effects of pH on RL or SF-enhanced biodegradation of diesel were in good agreement with the trends of emulsion index values for RL or SF addition, respectively, under different pH conditions, suggesting that enhanced diesel emulsification by RL or SF addition promoted biodegradation of diesel. In diesel-water systems with 50Â mg/L of RL addition, an optimum pH condition for microbial growth and diesel biodegradation was found to be at a pH 7.2, while decreasing pH to 5.2 or increasing it to 8.4 reduced those parameters considerably. For the cases where 40Â mg/L of SF was added, the enhancing ability shared a general trend with that observed for adding 50Â mg/L of RL as the pH increased from 5.2 to 7.2. Further increase of pH to 8.4, however, did not seem to negatively influence biodegradation and biomass growth. With respect to the effects of ammonium concentration on diesel biodegradation in diesel-water systems with 50Â mg/L of RL addition, an optimum ammonium addition for microbial growth and diesel biodegradation was found between 200 and 300Â mg-N/L, but a dramatic decrease in growth and biodegradation occurred at ammonium addition up to 450Â mg-N/L. For the cases where 40Â mg/L of SF was added, an increase of ammonium addition from 50 to 200Â mg-N/L substantially increased microbial growth and biodegradation of diesel. Further increase of ammonium concentration to 450Â mg-N/L, however, did not further improve diesel biodegradation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hazardous Materials - Volume 164, Issues 2â3, 30 May 2009, Pages 1045-1050
Journal: Journal of Hazardous Materials - Volume 164, Issues 2â3, 30 May 2009, Pages 1045-1050
نویسندگان
Liang-Ming Whang, Pao-Wen G. Liu, Chih-Chung Ma, Sheng-Shung Cheng,