A preliminary study on the phenolic degradation by Chlorella sp.

• Main Authors: Yu-Shan Huang, 黃于珊
• Other Authors: Sue-huai Gau
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/50235423292711073518

碩士 === 淡江大學 === 水資源及環境工程學系碩士班 === 103 === Phenolic compounds are commonly used in many industries, which discharge into wastewater with the characteristics of toxic and low biodegradability. Physical or chemical treatments are costly and easily generate secondary pollutants, while biological methods produce large amounts of waste sludge, which cost much during the final disposal. Microalgae have been proven to have the ability to remove the organic carbon, nitrogen, and phosphorous in the wastewater, and produce bioenergy simultaneously, nevertheless, the degradation ability and phenomenon on the phenolic compounds still not clear. In this study, chlorella sp. was cultured in up to 1000 mg phenol /L contained culture media; subsequently, the growth rates of chlorella and residual phenol concentration were examined, and the extent of chlorella toleration was investigated, GC/MS analysis was executed to exam the intermediate products during the phenolic degradation. Finally, growth kinetic model was simulated to investigate the growth rate of chlorella. The results indicated that 200 mg phenol /L initial concentration has the maximum chlorella growth rate, and 100–300 mg/L of phenol can be removed completely within 48–84 hours, the removal rate of total organic carbon was 96%–100%. Whereas exceeded 600 mg phenol/L, the growth of chlorella was inhibited, and at 1000 mg phenol /L of initial concentration, the growth of chlorella biomass and phenol degradation were stope. On the basis of the GC/MS results, phenol is inferred to have entered the tricarboxylic acid cycle following the meta-cleavage process. The simulation with Monod equation at 100–400 and 600–1000 mg phenol/L, the R2 were 0.84 and 0.64 respectively, it showed that, high concentration of phenol inhibits chlorella growth so the Monod equation was not applicable in this study. In contrast, the Haldane equation yielded R2 of 0.95 and 0.99 respectively, indicating that this equation was superior to the Monod equation and thus it can be applied in the simulation of this study.