水质.n日生化需氧量(BODn)的测定.第2部分:未稀释样品的测定法

[中文适用范围]： ISO 5815 的这一部分规定了未稀释样品的水的生化需氧量 (BOD) 的测定。 它适用于生化需氧量大于或等于 0.5 毫克/升（测定极限）且不超过 6 毫克/升氧的所有水体。 获得的结果是生化和化学反应结合的产物。 它们不具有由例如单一的、明确定义的化学过程产生的那些的严格和明确的特征。 然而，它们提供了可以估计水质的指示。 测试可能会受到各种物质存在的影响。 那些对微生物有毒的物质，例如杀菌剂、有毒金属或游离氯，会抑制生化氧化。 藻类或硝化微生物的存在会产生人为的高结果。 在这些情况下，可能需要对该方法进行修改。 附录 A 描述了替代的潜伏期。 附录 B 描述了通过添加晶种材料、盐、通过添加烯丙基硫脲 (ATU) 抑制硝化、中和、均化和/或过滤来修改方法的程序。 这些修改可能对于受纳水体水质的具体评估是必要的。 附录 C 提供了精确数据。 [外文原描述]： ISO 5815-2:2003 specifies determination of the biochemical oxygen demand of waters of undiluted samples. It is applicable to all waters having biochemical oxygen demands greater than or equal to 0,5 mg/l of oxygen (the limit of determination) and not exceeding 6 mg/l of oxygen. The results obtained are the product of a combination of biochemical and chemical reactions. They do not have the rigorous and unambiguous character of those resulting from, for example, a single, well-defined, chemical process. Nevertheless, they provide an indication from which the quality of waters can be estimated. The test can be influenced by the presence of various substances. Those which are toxic to microorganisms, for example bactericides, toxic metals or free chlorine, inhibit biochemical oxidation. The presence of algae or nitrifying microorganisms can produce artificially high results. In these situations a modification of the method may be necessary. Annex A describes alternative incubation periods. Annex B describes procedures for modification of the method by addition of seeding material, salts, inhibition of nitrification by allylthiourea (ATU) addition, neutralization, homogenization and/or filtration. These modifications may be found necessary for specific evaluations of the water quality of receiving waters. Annex C provides precision data.