HCO3-在部分亚硝化中功能及对亚硝化效能影响

通过接种成熟的亚硝化生物膜研究了HCO3-在部分亚硝化过程的主要功能,为部分亚硝化-厌氧氨氧化联合工艺处理高氨氮低碳废水时亚硝化段碳源需求提供依据.结果表明,维持进水氨氮浓度不变,通过降低HCO3-浓度将进水C/N比维持在1.8时,反应器内亚硝化效能达到0.99kg/(m3·d);逐步降低C/N比至0.5时,因HCO3-不够维持亚硝化体系pH值环境,导致亚硝化效能下降至0.67kg/(m3·d).C/N比维持在0.75时,基本能够维持亚硝化过程所需要pH值为8的环境.亚硝化过程中HCO3-的消耗量与亚硝化效能具有明显的线性关系.当利用低浓度强碱将反应器内pH值维持在8时,空气和水中微量碳源就能够满足亚硝化过程的碳源需求,亚硝化效能最高达到1.28kg/(m3·d).说明HCO3-在部分亚硝化过程中主要功能是中和亚硝化过程产生的H+,维持亚硝化菌所需要的pH值环境.

The function of HCO3- in the partial nitrification and influence on nitrification efficiency

The main function of HCO3- in partial nitrification process was investigated by inoculating nitrification biofilm and to provide carbon source demand of nitritation stage in partial nitrification/anammox process to treat wastewater with high ammonia nitrogen and low carbon. The results show that the nitrification efficiency reached 0.99 kg/(m3·d) when the C/N ratio remained at 1.8 under the conditions of only decreasing influent concentration of HCO3- and unchanged ammonia concentration. However, the nitrification efficiency decreased to 0.67kg/(m3·d) at the same conditions, because the concentration of HCO3- was not enough to sustain pH environment in the nitrosation system, when C/N gradually reduced to 0.5. The pH value stabled at 8in nitrosation process, when the C/N ratio remained at 0.75. It had an obvious linear relationship between consumption of HCO3- and nitrification efficiency in nitrosation process. The tiny carbon in the air and wastwater meeted the demand of carbon source and the nitrification efficiency rate was up to 1.28kg/(m3·d) in nitrification process, when the pH value stabled at 8by using low concentration of alkali. The results indicated that neutralizing H+ produced by nitrification process and maintaining the pH environment needed for nitrosomonas were the main function of HCO3- in the partial nitrification process.