| 摘要: | 本研究分別以實廠污泥進行批次式異營脫硝實驗，以及利用馴養後污泥進行批次式自營脫硝實驗，並分別評估其脫硝特性以及對其脫硝過程進行動力描述。
研究結果顯示加入醋酸鹽作為額外碳源進行脫硝時，其脫硝速率約為以甲醇及糖蜜作為碳源的2~3倍。利用醋酸鹽及糖蜜作為額外碳源脫硝時，在脫硝過程中會有脫硝中間產物亞硝酸鹽氮累積，且同時觀察到氨氮濃度下降之情況。當COD負荷提高時，糖蜜作為碳源產生的亞硝酸鹽氮濃度會隨之提升。使用醋酸鹽作為碳源添加能在8小時達到98%的額外添加COD去除率，甲醇及糖蜜則約為40%，有明顯COD殘留現象。
甲醇及C/N比為3、4的醋酸鹽脫硝動力以0階及1階函數擬合時經統計變異數分析沒有顯著差異，糖蜜脫硝動力統計上則呈現1階函數，而醋酸鹽在C/N比為5、6時為0階函數。推測脫硝過程中糖蜜因碳源生物代謝特性之限制條件下，脫硝動力呈現1階特性，而醋酸鹽碳源C/N比為5、6，在碳源特性及濃度未受限制的情況下則能呈現0階脫硝動力特性。
自營脫硝生物依本研究馴養條件操作後約1個月能使微生物在12小時內去除100 mg/L的硝酸鹽氮，達到馴養之目標。自營性脫硝實驗中，在硝酸鹽氮添加低於100 mg/L的條件下，能在8小時內完全去除硝酸鹽氮，但各組別皆產生高濃度亞硝酸鹽氮累積。脫硝過程中發現硫代硫酸鹽在日光較多的環境下被氧化的比例較高。
自營性脫硝過程中硝酸鹽氮濃度變化為1階反應，而硫代硫酸鹽氧化情況較接近0.5階反應，推測在自營性脫硝過程中，脫硝動力受電子供體代謝特性及過高濃度的亞硝酸鹽影響，而使脫硝動力呈現此特性。;This research conducts the batch heterotrophic denitrification experiments of active sludge from science industrial park, and the batch autotrophic denitrification experiments by acclimated sludge. The denitrification characteristics and the kinetic description of the denitrification process are also evaluate.
The research results show that when using acetate as an additional carbon source for denitration, the denitration rate is about 2 to 3 times that of methanol and molasses as the carbon source. When using acetate and molasses as additional carbon sources for denitrification, nitrite, which is an intermediate product of denitrification, will accumulate during the denitrification process, at the same time, it is observe that the concentration of ammonia nitrogen decreases. Moreover, if used molasses as an additional carbon source, when the COD loading increases, nitrite concentration will increase at the same time. Using acetate as an additional carbon source have 90% of the external carbon source removal ratio in 8 hours, while methanol and molasses are only 40%, there have COD residual in the effluent obviously.
The denitration kinetic of using methanol and C/N ratio 3 and 4 of acetate as an additional carbon source have no significant difference between the fitting of 0-order and 1-order function in analysis of variance. Using molasses as an additional carbon source is fit to 1-order function. While using C/N ratio is 5 or 6 of acetate as an additional carbon source is fit to 0-order function. It is speculate the denitrification kinetics of molasses is the restriction by the biological metabolic characteristics of carbon sources, that it presents 1-order denitrification kinetics. While using C/N ratio is 5 or 6 of acetate as an additional carbon source, the carbon source metabolic characteristics and concentration are not the restriction, that it present the 0-order denitration kinetics.
The autotrophic denitrification organisms can remove 100 mg/L of nitrate nitrogen within 12 hours after operating under the acclimated conditions in this study for about one month. In autotrophic denitrification experiments, when nitrate is added less than 100 mg/L, it can be completely remove within 8 hours. However, each experiments batch produces high concentration nitrite. During the autotrophic denitrification, data shows that the oxidation quantity of thiosulfate is more than the production of sulfate when the daytime.
Nitrate concentration change in the autotrophic denitrification is fit to 1-order function, while thiosulfate concentration change is fit to the 0.5-order reaction. It is speculate that in the autotrophic denitrification process, the denitrification kinetic order is affected by the metabolic characteristics of thiosulfate and the excessively high concentration of nitrite. |
