Ammonia removal is achieved partly by absorption and nitrification in biofilters, resulting in the accumulation of nitrogen and the necessity of treating the effluent water. We investigated the effects of thiosulfate addition to a biofilter containing pumice tuff for ammonia and nitrogen removal in a laboratory-scale experiment. The addition of thiosulfate to the circulating water led to a decreased nitrate and nitrite along with an increase of sulfate. The inorganic nitrogen in the circulating water decreased by up to 44% with thiosulfate addition compared to without thiosulfate. Batch experiments revealed that denitrification activity decreased exponentially along with increases in dissolved oxygen; however, approximately 30% of denitrification activity was maintained at dissolved oxygen concentration of 3.3 mg/L. Metabarcoding of 16S rRNA genes indicated that the genus Thiobacillus had a relative abundance of 0.002%-0.016% of total bacteria in the biofilter packing material. The circulating water pH was decreased below 5 with sulfur oxidation, and ammonium was accumulated without pH control resulting in a decrease in the relative abundance of the family Nitrosomonadaceae. Its relative abundance increased with control of pH to near neutral, indicating that ammonia-oxidizing activity could be maintained by adjusting pH. Thiosulfate addition could stimulate nitrogen removal by sulfur-dependent denitrification in biofiltration systems.

中文翻译：

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添加硫代硫酸盐对填充 Oyaishi（浮石凝灰岩）的生物过滤器中氨和氮去除的影响。

氨的去除部分是通过生物过滤器中的吸收和硝化作用实现的，导致氮的积累和处理流出水的必要性。我们在实验室规模的实验中研究了将硫代硫酸盐添加到含有浮石凝灰岩的生物过滤器中去除氨和氮的效果。向循环水中添加硫代硫酸盐导致硝酸盐和亚硝酸盐减少以及硫酸盐增加。与不添加硫代硫酸盐相比，添加硫代硫酸盐后循环水中的无机氮最多可减少 44%。批次实验表明，随着溶解氧的增加，反硝化活性呈指数下降；然而，大约 30% 的反硝化活性在溶解氧浓度为 3.3 mg/L 时保持。16S rRNA 基因的元条形码表明硫杆菌属在生物滤池填料中的相对丰度为总细菌的 0.002%-0.016%。随着硫氧化，循环水的 pH 值降低到 5 以下，并且在没有 pH 控制的情况下积累铵，导致亚硝化单胞菌科的相对丰度下降。它的相对丰度随着 pH 值控制在接近中性而增加，表明氨氧化活性可以通过调节 pH 值来维持。添加硫代硫酸盐可以促进生物过滤系统中硫依赖性反硝化作用的脱氮作用。和铵在没有 pH 控制的情况下积累，导致 Nitrosomonadaceae 科的相对丰度下降。它的相对丰度随着 pH 值控制在接近中性而增加，表明氨氧化活性可以通过调节 pH 值来维持。添加硫代硫酸盐可以促进生物过滤系统中硫依赖性反硝化作用的脱氮作用。和铵在没有 pH 控制的情况下积累，导致 Nitrosomonadaceae 科的相对丰度下降。它的相对丰度随着 pH 值控制在接近中性而增加，表明氨氧化活性可以通过调节 pH 值来维持。添加硫代硫酸盐可以促进生物过滤系统中硫依赖性反硝化作用的脱氮作用。