【摘要】 目的:旨在寻找生化需氧量(BOD)标准稀释法测定中稀释水的一些影响因素,提高测定的灵敏度与准确度,为今后的教学研究提供一定的参考。方法:分别以不同水源、不同曝气平衡时间、不同温度为研究条件测试稀释水的5d生化过程所消耗的氧量(BOD5),以确定最佳实验条件。结果:以蒸馏水和纯净水作为稀释水水源,其BOD5都小于0.2mg/L,均达到标准;平衡时间增长,当日溶解氧量趋于降低,与标准值的差值也逐渐增大,未经平衡的溶解氧量接近饱和;20℃时的测定结果达标。结论:以经济实用的蒸馏水为稀释水水源,在20℃恒温实验室进行测定,并在水样采集、稀释过程中严格遵守操作步骤,避免气泡的产生。更多还原

【Abstract】 Objective:To investigate factors in water-dilution affecting the determination results with biochemical oxygen demand (BOD5) standard dilution method, so as to improve the sensitivity and accuracy, and to provide rational suggestion for further study. Method: BOD5 in diluted water from different sources was determined with different balance times and different temperatures, by which the optimum experimental conditions were summarized. Result: When distilled water and purified water was used as diluting water, no obvious difference of BOD5 was found between them, and both the results reached the standard ( below 0.2 mg/L). Deliquescent oxygen reduced with longer balance time and greater difference from standard occurred. Before balancing,deliquescent oxygen was close to saturation. The results under 20 ℃ met the standard. Conclusion: For the consideration of BOD5 test accuracy and economic efficiency, it is suggested that using distilled water as diluting water and performing the test in lab with a constant temperature of 20 ℃. The instructions for water sample collection and dilution must be strictly followed to avoid bubbles.更多还原