研究結果發現，在酚濃度200 mg/L時可使小球藻達到最高比生長速率，而600 mg/L以上則開始對小球藻產生明顯抑制現象，當濃度為1000 mg/L時小球藻生物質量完全沒有增加，同時酚也幾乎沒有減少，而酚濃度100~300 mg/L可在48 ~ 84小時內完全去除，同時總有機碳去除率也有96~100 %。由GC/MS檢測結果顯示，推測酚經由間位裂解後進入三羧酸循環中。本研究利用Monod動力學模擬在100~400以及600~1000 mg/L時分為低濃度及高濃度兩段行計算，其R2值分別為0.8435及0.638，顯示在高濃度基質下會抑制小球藻生長，不適合使用Monod模式；而利用Haldane模式求得之R2值則分別為0.9527及0.9892，明顯優於Monod模式，較適合於本研究中模擬使用。
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.