| 摘要: | 家庭及工業廢水中含有氨氮物質及有機酸，其中氨水、丙酸及丁酸經常導致刺鼻氣味，然而，降解氨氮物質及有機酸的方法和過程繁瑣，且若處理不當就排放到環境中，會對環境造成嚴重影響。
Bacillus subtilis是一種革蘭氏陽性细菌，屬於芽孢桿菌科。它是一種廣泛存在於自然環境中的细菌，且具有高度的耐熱性及其能夠形成孢子以適應較為惡劣的環境。Bacillus subtilis具有多種代谢途径，能够利用有機物和氮源等污染物进行代谢，將其轉化為無害的產物。
因此Bacillus subtilis可以做為一種有效處理家庭污水的方法，通過加入 10 %(v/v) 的菌液至濃度為0.1M之氨水、丙酸、丁酸及上述三種之混和溶液，以每24小時取一點，共取7天，並以分光光度計檢測氨氮含量隨天數的變化，以氣相層析儀檢測丙酸及丁酸隨天數變化的含量。
實驗結果表明，不論是氨氮含量抑或是丙酸和丁酸的含量，在與Bacillus subtilis BCRC10029發酵之後，其三者的含量皆有隨著天數的增加而下降的趨勢，在最佳環境條件下，Bacillus subtilis BCRC10029降解消耗的氨氮共減少了84.4%，丙酸從3.54%被降解消耗至0%，而丁酸也從36.1%下降到15.4%。在混和溶液中，以不同菌液濃度接種由低至高對於氨氮的變化為56.9%、52.2%、65.9%及58.8%。不同菌液濃度對丙酸的降解消耗，在發酵到第7天時，丙酸的殘留量皆趨近於0，而丁酸的殘留量也有一定程度的減少，顯示出Bacillus subtilis BCRC10029具有可消耗氨氮、丙酸及丁酸的能力。
;Domestic wastewater contains ammonia nitrogen substances and organic acids, among which ammonia water, propionic acid and butyric acid often cause pungent odors. However, the method and process of degrading ammonia nitrogen substances and organic acids are cumbersome, and if they are not properly treated, and straightly discharged into the sewer, which will have a negative impact on the environment.
Bacillus subtilis is a Gram-positive bacterium that belongs to the Bacillus family. It is a bacterium that widely exists in the natural environment and is highly heat-resistant and capable of forming spores to adapt to harsher environments. Bacillus subtilis has a variety of metabolic pathways, which can metabolize pollutants such as organic matter and nitrogen sources, and convert them into harmless products.
Therefore, in this experiment Bacillus subtilis BCRC10029 is used as a method to treat domestic wastewater. By adding 10% (v/v) of the bacterial suspensions to a concentration of 0.1M ammonia, propionic acid, butyric acid and the mixed solution of the above three, a sample is taken every 24 hours for a total of 7 days, and the change of ammonia nitrogen content with the number of days was detected with a spectrophotometer, and the content of propionic acid and butyric acid with the number of days was detected with a gas chromatograph.
The experimental results show that no matter the content of ammonia nitrogen or the content of propionic acid and butyric acid, after fermentation with Bacillus subtilis BCRC10029, the contents of the three all have a downward trend with the increase of days. Under the best environmental conditions, Bacillus subtilis BCRC10029 The ammonia nitrogen consumed by the degradation of Bacillus subtilis BCRC10029 decreased by 84.4%, propionic acid was degraded and consumed from 3.54% to 0%, and butyric acid also decreased from 36.1% to 15.4%. In the mixed solution, the changes of ammonia nitrogen were 56.9%, 52.2%, 65.9% and 58.8% when inoculated with different bacterial concentration from low to high. The degradation and consumption of propionic acid by different concentrations of bacteria suspensions, the residual amount of propionic acid tended to 0 on the 7th day of fermentation, while the residual amount of butyric acid also decreased to a certain extent, showing that Bacillus subtilis BCRC10029 has the ability to degrade and consume ammonia nitrogen, propionic acid and butyric acid. |
