This study investigated the effects of hydraulic retention time, nitrate loading rate, as well as seed sludge on nitrate removal by using elemental sulfur-based carriers in upflow packed-bed bioreactors. The results showed that nitrate removal efficiency improved by 28 % with increasing hydraulic retention time from 1 h to 4 h. The nitrate removal rate achieved 84 ± 1% at a loading rate of 0.20−0.40 kgNO₃⁻-N/m³/d and decreased by 54 % after triggering a loading rate of 1.20 kgNO₃⁻-N/m³/d. Besides, nitrite accumulation was noticeable, with nitrite effluent concentration being 15.9–16.6 mgNO₂⁻-N/L, as operating at nitrate loading over 0.80 kgNO₃⁻-N/m³/d. Interestingly, after enriching seed activated sludge, the sum proportion of Thiobacillus and Sulfurimonas (well-known denitrifying bacteria) increased from 17.1 to 18.4% to 55.4–56.3 %, which improved nitrate removal efficiency to 90 ± 3%. Overall, the high nitrate removal rate of 0.36 kgNO₃⁻-N/m³/d demonstrated that elemental sulfur-based carrier is a powerful candidate to apply for autotrophic denitrification.

这项研究调查了水力停留时间，硝酸盐上样速率以及种子污泥在上流式填充床生物反应器中使用基于元素硫的载体对硝酸盐去除的影响。结果表明，随着水力停留时间从1 h增加到4 h，硝酸盐去除效率提高了28％。在0.20-0.40 kgNO ₃ ^-- N / m ³ / d的加载速率下，硝酸盐去除率达到84±1％，在触发1.20 kgNO ₃ ^-- N / m ³ / d的加载速率后，硝酸盐去除率降低了54％。此外，亚硝酸盐积累明显，用亚流出物浓度为15.9-16.6 mgNO ₂ ^- -N / L，如硝酸盐负荷超过0.80 kgNO操作₃ ^--N / m ³ / d。有趣的是，富集了种子活性污泥后，硫杆菌和磺脲类（众所周知的反硝化细菌）的总比例从17.1％增加到18.4％，达到55.4-56.3％，这将硝酸盐去除率提高到90±3％。总体而言，硝酸盐的高去除率为0.36 kgNO ₃ ^-- N / m ³ / d，这表明元素硫基载体是自养反硝化应用的有力候选者。