GB/T 7488-1987 in English

《GB/T 7488-1987水质 五日生化需氧量（BOD5）的测定 稀释与接种法》由467（生态环境部）归口，主管部门为生态环境部。
本方法适用于BOD5大于或等于2mg/L并且不超过6000mg/L的水样。BOD5大于6000mg/L的水样仍可用本方法，但由于稀释会造成误差，有必要要求对测定结果做深重的说明。本试验得到的结果是生物化学和化学作用共同产生的结果，它们不象单一的、有明确定义的化学过程那样具有严格和明确的特性，但是它能提供用于评价各种水样质量的指标。本试验的结果可能会被水中存在的某些物质所干扰，那些对微生物有毒的物质，如杀菌剂、有毒金属或游离氯等，会抑制生化作用。水中的藻类或硝化微生物也可能造成虚假的偏高结果。

Scope

This method is applicable to water samples with BOD₅ greater than or equal to 2mg/L and not exceeding 6000mg/L. This method can still be used for water samples with BOD₅ greater than 6000mg/L, but due to dilution will cause errors, it is necessary to require careful explanation of the measurement results. The results obtained in this test are the result of the combination of biochemistry and chemistry, they are not as strict and well-defined as a single, well-defined chemical process, but it can provide indicators for evaluating the quality of various water samples . The results of this test may be disturbed by the presence of certain substances in the water that are toxic to microorganisms, such as fungicides, toxic metals or free chlorine, etc., which inhibit biochemical action. Algae or nitrifying microorganisms in the water may also cause falsely high results.