Complete removal of nitrogen, sulfur and carbon in wastewaters by denitrifying sulfide removal (DSR) process can be achieved at stoichiometry sulfide to nitrate ratio (S/N) of 1:1 in expanded granular sludge bed reactor. Wastewaters with varying S/N ratios can adversely impact the DSR performances with deterioration of synergetic cooperation between autotrophic and heterotrophic denitrifiers. DO (dissolved oxygen) serves effectively as supplementary electron receiver for sulfide oxidation, leaving more nitrate for heterotrophic denitrifiers to utilize acetate. The optimal oxygen to sulfide molar ratio (DO/S) is 0.5:1 for complete removal of sulfide, nitrate and acetate at different S/N ratios. The heterotrophic denitrification rate was decreased to 0.03 ± 0.002, 0.24 ± 0.011 and 0.35 ± 0.027 NO₃⁻-N·h⁻¹·gVSS⁻¹ at S/N ratio of 5:2, 5:5 and 5:8, respectively, when DO/S of 3:1 was performed. This optimal condition was proposed as an easy-to-implement control criterion for subsiding the adverse impact by varying S/N ratios in handling real wastewaters.

在膨胀的颗粒污泥床反应器中，化学计量的硫化物与硝酸盐之比（S / N）为1：1时，可通过脱硝硫化物脱除（DSR）工艺完全去除废水中的氮，硫和碳。具有不同信噪比的废水会损害自养反硝化装置和异养反硝化装置之间的协同作用，从而对DSR性能产生不利影响。DO（溶解氧）有效地充当了硫化物氧化的辅助电子接收器，为异养反硝化剂留下了更多的硝酸盐以利用乙酸盐。最佳氧气与硫化物的摩尔比（DO / S）为0.5：1，以完全去除不同S / N比的硫化物，硝酸盐和乙酸盐。异养脱氮率降低至0.03±0.002，±0.24 0.011 0.35±0.027 NO ₃ ^-当执行3：1的DO / S时，分别以5：2、5：5和5：8的S / N比-N·h ^-1 ·gVSS ^-1。提出了此最佳条件，作为易于实施的控制标准，通过改变实际废水中的信噪比来消除不利影响。