硝化基质和产物对发光细菌的急性毒性

摘要：【目的】对硝化基质和产物对硝化过程的影响进行初步研究。【方法】采用发光细菌法，在pH=7.0的条件下，测定了氨、羟胺、亚硝酸和硝酸对发光细菌的急性毒性（15min-半抑制浓度（the half inhibitory concentration，IC50））。【结果】单一物质的毒性试验结果表明，硝化基质和产物对发光细菌的毒性随浓度的升高而增大，且具有较好的线性关系；氨、羟胺、亚硝酸和硝酸的IC50分别为2180.2 mg/L、6.2740 mg/L、1207.2 mg/L和3140.3 mg/L；其毒性大小顺序为：羟胺 >亚硝酸 >氨 >硝酸。按等效浓度混合法测定硝化基质和产物的联合毒性，结果表明：氨与羟胺、氨与亚硝酸、羟胺与亚硝酸对发光细菌的联合毒性呈相加作用；氨与硝酸、羟胺与硝酸、亚硝酸与硝酸对发光细菌的联合毒性呈独立作用；氨、羟胺、亚硝酸、硝酸四元混合物的联合毒性也呈相加作用。【结论】根据硝化基质和产物对发光细菌和硝化细菌抑制浓度的相关性，可用发光细菌发光强度的变化指示硝化基质和产物的抑制作用。

Toxicity of nitrification substrates and products to photobacterium

Abstract: Objective] In this study, we studied the toxic effect of nitrification substrates and products on photobacterium. Methods] The acute toxicities of nitrification substrates and products to photobacterium were studied with the 15-min half inhibitory concentration (IC50) as indicator at pH=7.0. Results] The results of individual toxicity indicated that the toxicity of nitrification substrates and products to photobacterium increased with increasing concentration and there was a linear correlation. The IC50 values of ammonium, hydroxylamine, nitrite and nitrate were 2180.2 mg?L-1, 6.2740 mg?L-1, 1207.2 mg?L-1 and 3140.3 mg?L-1, respectively, and their toxic order was hydroxylamine> nitrite> ammonium> nitrate. The combined effects of substrates and products were assayed by equivalent concentration mixing method. The results showed that the combined effects of ammonium and hydroxylamine, ammonium and nitrite, hydroxylamine and nitrite were additive effects, whereas the combined effects of ammonium and nitrate, hydroxylamine and nitrate, nitrite and nitrate were independent effects. The combined effect of all nitrification substrates and productions was also additive effect. Conclusion] According to the correlation of the inhibiting concentration to photobacterium and nitrifying bacterium by nitrification substrates and products, the change of luminous intensity of photobacterium can indicate the inhibition from nitrification substrates and products.