废水可生物降解COD组分2种表征方法的比较

利用自行开发的混合呼吸速率测量仪在接种污泥的条件下对重庆某城市污水处理厂污水进行了呼吸速率测试（短期BOD测试，以呼吸速率测量重新进入内源呼吸阶段为结束）；同时应用美国产BI-2000电解质呼吸仪在不接种污泥的条件下对该污水进行了BOD测试（长期BOD测试，理论上以污水中所有有机物矿化为结束）。对2种测试方法及其结果进行了比较，结果表明，2种方法得到的BCOD存在很大差异，短期BOD测试方法得到的结果仅为长期BOD测试方法得到的结果的40％～60％。通过批式呼吸测量方法测定了原废水中的活性异养微生物浓度XH(0)，结果表明，XH(0)与BCOD_st之和与BCOD_lt比较接近，两者之比在0.88～1.02之间，平均值为0.94。

Comparison of two methods for characterising biodegradable COD of wastewater

For the wastewater in a certain wastewater treatment plant in Chongqing, its respiration rate un-der seeded sludge condition was measured by the self-developed respirometer and the end of this short-term BOD test was defined as the time when endogenous respiration restarted; besiedes, BI-2000 electrolytic respirometer was utilized to test BOD under un-seeded sludge condition and this long-term BOD test is theoretically ended with organism mineralized. The comparation between the results of the two experiment methods show that, the BCOD obtained by the two methods is quite different and the short-term BOD measurement result was only 40% ～60% of the long-term BOD measurement result. The concentration of heterotrophic microorganisms, X_H(0) , of the raw wastewater was tested through the batch respirometry. The result showed that the ratio of the sum of X_H(0) and BCOD_(st) to BCOD_(lt) was between 0. 88 ～ 1. 02 with an average of 0. 94, indicating that the sum was closed to BCOD_(lt).