海水观赏鱼居室养殖循环系统中三态氮的变化规律及硝化细菌对水质的影响

于 2005年 3月 5日 ~5月 3日连续监测了海水观赏鱼居室养殖循环系统的水质，研究该系统中三态氮的变化规律以及添加硝化细菌后对水质的影响。结果表明：1)试验初期氨氮的质量分数迅速上升， 在 1周内达到高峰(峰值2．56mg/L)，并在1．50mg/L的范围内维持 1周左右，此后迅速下降至0．01mg/L 左右，并一直维持在该水平直至试验结束。亚硝态氮的质量分数在氨氮的质量分数迅速回落时(约试验开始后 2周)呈现出直线上升的趋势，并在 3~3．5mg/L左右的水平上维持 2~3周时间(峰值为3．65 mg/L)，此后迅速下降至0．01mg/L以下，并一直维持在低水平直至试验结束。而硝酸盐的质量分数在整个试验期间基本保持稳定上升的趋势，至本试验末期，NO₃ ^- -N的质量分数达到 15mg/L左右。2)系统的生物滤器需要 4~5周左右时间才能基本成熟，即氨氮和亚硝酸氮均降至 ＜0．01mg/L，到达安全的质量分数，适合海水观赏鱼健康生长。3)添加硝化细菌的试验组，氨氮和 NO₃ ^- -N的质量分数变化与对照组基本相似，而 NO₂ ^- -N的质量分数变化与对照组明显不同。试验组从高质量分数水平迅速下降的时间比对照组提前了约 1周。

Variations of NH3 -N, NO2 - -N and NO3 - -N in Water Recirculating System for Marine Ornamental Fish Culture in Living-Room and Effects of Nitrifiers on the Water Quality

The studies on the Variations of NH₃ -N, NO₂ ^- -N and NO₃ ^- -N in closed water re-circulating system for marine ornamental fish culture in living-rooms or offices and effects of nitrofiers added on the water quality were carried out. The results are summarized as follows:(1) The concentration of NH₃ -N increased rapidly from the beginning of the experiment, and reached the maximum of 2.56 mg/L on the first week, then it began to drop quickly to about 1.50 mg/L, and maintained the level about 1 week, and then it decreased further to about 0.01 mg/L till the end of the experiment. At the time of the concentration of NO₂ ^- -N rose rapidly, NO₃ ^- -N fell (two weeks after the start of experiment) and came to the maximum of 3.65 mg/L on the 4th week. Keeping the level about 2-3 weeks, it decreased quickly till about 0.01 mg/L, and remained at the level to the end of the experiment. The concentration of NO₃ ^- -N went up steadily from the beginning to the end of the experiment.(2)It needed about 4-5 weeks to be matured for the re-circulating system in which ammonia and nitrite-N reached to the safety level, and the ornamental fish could live healthily. (3) The concentration of NH₃ -N and NO₃ ^- -N between the control and the trial in which nitrofiers were added showed no difference, but the rapid decline of NO₂ ^- -N concentration from higher level (3 mg/L) in trial group happened 1 week earlier than that in control group.