在东湾市政公用事业区（区）进行的中试和台架试验表明，阳离子处理 聚合物二烯丙基二甲基氯化铵（DADMAC）是受试水体中N-亚硝基二甲胺（NDMA）前体的唯一重要来源。水平 随着阳离子聚合物剂量的增加和接触时间的延长，形成的NDMA增加 用氯胺。较高的NDMA水平通过预氨化或 同时添加氯和氨，而游离氯的接触时间为 氯胺化前三到四个小时导致NDMA水平降低。应用 使用非离子絮凝剂或助滤剂可降低氯胺化溶液中的NDMA浓度- 成品水，可能是由于在生产过程中更好地去除残余阳离子聚合物 沉淀和过滤。 中间臭氧氧化和peroxone工艺并没有增加NDMA的生成，但 而似乎降低了整体水平。在试验中形成了类似水平的NDMA 当明矾或三氯化铁用作一级混凝剂时。 过滤速率 通过无烟煤/砂过滤介质，3到6 gpm/sf之间的变化不会影响过滤效果 NDMA组。 回收的过滤器反洗上清液是NDMA前体的重要来源， 可能是由于该流中含有残余阳离子聚合物。不知道是什么 该循环水流可能影响成品水NDMA水平的程度；大概是 大部分聚合物通过过滤回收。包括15个参考文献、表格和图表。

Pilot and bench testing conducted at the East Bay Municipal Utility District (District) indicated that cationic treatment polymer, diallyldimethylammonium chloride (DADMAC), was the only significant source of N-nitrosodimethylamine (NDMA) precursors in tested waters. The levels of NDMA formed increased with higher cationic polymer doses and longer contact times with the chloramines. Higher NDMA levels were measured with preammoniation or simultaneous addition of chlorine and ammonia, whereas free chlorine contact time for three to four hours prior to chloramination resulted in lower NDMA levels. Application of nonionic flocculant or filter aid may lower NDMA concentrations in chloraminated- finished water, possibly due to better residual cationic polymer removal during sedimentation and filtration. Intermediate ozonation and peroxone process did not increase NDMA formation but rather appeared to lower the overall levels. Similar levels of NDMA were formed in test waters when either alum or ferric chloride was used as the primary coagulant. Filtration rate variations between 3 and 6 gpm/sf through anthracite/sand filter media did not impact NDMA formation. Recycled filter backwash supernatant was a significant source of NDMA precursors, possibly due to residual cationic polymer contained in this stream. It is unknown to what extent this recycled stream may impact finished water NDMA levels; presumably the majority of recycled polymer is removed by clarification and filtration. Includes 15 references, tables, figures.