碳酸钠对生物滤池硝化作用及水体pH的影响

Effect of Na_2CO_3 on Nitrification and Water Body pH in the Biofilter

[目的]寻找适合在RAS系统的碱性添加剂,为在封闭式循环水养殖系统中(RAS)合理使用Na2CO3提供理论依据。[目的]通过设置不同梯度的Na2CO3添加量,研究其对生物滤池硝化反应的影响过程和引起水体p H变化的情况。[结果]与对照组相比,添加适量Na2CO3不会显著增强生物滤池对TAN和NO-2-N的去除效果,但会在短时间内加快硝化反应的进行,其中添加量分别为80和160mg/L的C组和D组在反应6 h时,硝化反应速率比其他3组更快,试验结束时各组之间几乎没有差异。此外,添加Na2CO3还会延缓水体p H随着反应的进行下降的趋势,而延缓程度随着Na2CO3添加量的增加而增大。[结论]该研究可为Na2CO3在RAS系统中的合理使用提供理论依据。

Objective] To correctly understand and rationally use Na2CO3 as alkaline additives in the closed recirculation aquaculture systems （RAS）.[Method] By adding Na2CO3 at a gradient of concentrations to the biofilter, the effects of Na2CO3 on biofilter nitrification process and the changes of pH value in the water were preliminarily studied.[Result] Compared to the control group, adding proper amount of Na2CO3 did not significantly enhance the removal effect of TAN and NO2--N in the biofilter, but accelerated the nitration reaction in a short time.After 6h of reaction, the nitrification rates of treatments C and D were faster than the other three treatments .By the end of the experiment, there was almost no difference between the treatments.In addition, adding Na2CO3 delayed the downtrend of pH in the water, and the degree of delay increased with the adding of Na2CO3.[Conclusion] This research provides theoretical foundation for the rational utilization of Na2CO3 in RAS system.