水质 N天后测定生物氧化需氧量（BODN） 第1部分:具有全脂添加剂的稀释和种子方法

[中文适用范围]： 本文件规定了通过稀释和接种并在 5 天或 7 天培养时间后抑制硝化作用来测定水体的生化需氧量。 它适用于生化需氧量通常在 1 毫克/升到 6000 毫克/升之间的所有水体。 它特别适用于废水，但也适用于天然水的分析。 对于生化需氧量大于 6000 mg/l 的氧气，该方法仍然适用，但需要特别注意准备稀释步骤时二次取样的代表性。 获得的结果是生物化学和化学反应在活物质存在下的组合产物，其行为仅具有偶尔的再现性。 结果不具有例如由单一的、明确定义的化学过程所产生的结果的严格和明确的特征。 然而，结果提供了可以估计水质的指示。 [外文原描述]： This document specifies the determination of the biochemical oxygen demand of waters by dilution and seeding with suppression of nitrification after 5 d or 7 d incubation time. It is applicable to all waters having biochemical oxygen demands usually between 1 mg/l and 6 000 mg/l. It applies particularly to waste waters but also suits for the analysis of natural waters. For biochemical oxygen demands greater than 6 000 mg/l of oxygen, the method is still applicable, but special care is needed taking into consideration the representativeness of subsampling for preparation of the dilution steps. The results obtained are the product of a combination of biochemical and chemical reactions in presence of living matter which behaves only with occasional reproducibility. The results do not have the rigorous and unambiguous character of those resulting from, for example, a single, well‑defined, chemical process. Nevertheless, the results provide an indication from which the quality of waters can be estimated.