Oasen Drinking Water Company, PO Box 122, 2800 AC Gouda, The Netherlands.
Water Res. 2011 Jul;45(13):4008-18. doi: 10.1016/j.watres.2011.05.005. Epub 2011 May 17.
In groundwater treatment for drinking water production, the causes of nitrification problems and the effectiveness of process optimization in rapid sand filters are often not clear. To assess both issues, the performance of a full-scale groundwater filter with nitrification problems and another filter with complete nitrification and pretreatment by subsurface aeration was monitored over nine months. Quantitative real-time polymerase chain reaction (qPCR) targeting the amoA gene of bacteria and archaea and activity measurements of ammonia oxidation were used to regularly evaluate water and filter sand samples. Results demonstrated that subsurface aeration stimulated the growth of ammonia-oxidizing prokaryotes (AOP) in the aquifer. Cell balances, using qPCR counts of AOP for each filter, showed that the inoculated AOP numbers from the aquifer were marginal compared with AOP numbers detected in the filter. Excessive washout of AOP was not observed and did not cause the nitrification problems. Ammonia-oxidizing archaea grew in both filters, but only in low numbers compared to bacteria. The cell-specific nitrification rate in the sand and backwash water samples was high for the subsurface aerated filter, but systematically much lower for the filter with nitrification problems. From this, we conclude that incomplete nitrification was caused by nutrient limitation.
在地下水处理饮用水生产中，硝化问题的原因以及快速砂滤器中工艺优化的效果往往不明确。为了评估这两个问题，对一个有硝化问题的全规模地下水过滤器和另一个经过地下曝气预处理和完全硝化的过滤器进行了九个月的监测。使用针对细菌和古菌的 amoA 基因的定量实时聚合酶链反应 (qPCR) 和氨氧化活性测量定期评估水样和滤砂样本。结果表明，地下曝气刺激了含水层中氨氧化原核生物 (AOP) 的生长。使用每个过滤器的 AOP 的 qPCR 计数进行细胞平衡计算，表明与过滤器中检测到的 AOP 数量相比，接种的 AOP 数量微不足道。没有观察到 AOP 的过度冲洗，也没有导致硝化问题。氨氧化古菌在两个过滤器中均有生长，但与细菌相比数量很少。在地下曝气过滤器中，砂和反冲洗水中的细胞特异性硝化率很高，但对于有硝化问题的过滤器，该值系统地低得多。由此我们得出结论，不完全硝化是由营养限制引起的。
