College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China; Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 2W2, Canada.
Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 2W2, Canada.
J Hazard Mater. 2022 Feb 15;424(Pt B):127527. doi: 10.1016/j.jhazmat.2021.127527. Epub 2021 Oct 16.
Nitrate has been widely used in sewer systems for sulfide control. However, significant chemical consumption and the loss of carbon source were observed in previous studies. To find a feasible and cost-effective control strategy of the sulfide control, the effect of nitrate combined with sodium nitroprusside (SNP) dosage strategy was tested in lab-scale sewer biofilm reactors. Results showed that nitrate and SNP were strongly synergistic, with 30 mg N/L nitrate and 20 mg/L SNP being sufficient for sulfide control in this study. While large amount of nitrate alone (100 mg N/L) is required to achieve the same sulfide control effectiveness. Meanwhile, the nitrate combined with SNP could reduce the organic carbon source loss by 80%. Additionally, the high-throughput sequencing results showed that the relative abundance of autotrophic, nitrate reducing-sulfide oxidizing bacteria genera (a-NR-SOB) such as Arcobacter and Sulfurimonas was increased by around 18%, while the heterotrophic, nitrate-reducing bacteria (hNRB) such as Thauera was substantially reduced. It demonstrated that the sulfide control was mainly due to the a-NR-SOB activity under the nitrate and SNP dosing strategy. The microbial functional prediction further revealed that nitrate and SNP promoted the dissimilatory nitrate reduction process which utilizes sulfide as an effective electron donor. Moreover, economic assessment indicated that using the combination of nitrate and SNP for sulfide control in sewers would lower the chemical costs by approximately 35% compared with only nitrate addition.
硝酸盐已广泛用于下水道系统中的硫化物控制。然而，在以前的研究中观察到化学物质消耗量大和碳源损失。为了找到一种可行且具有成本效益的硫化物控制策略，本研究在实验室规模的下水道生物膜反应器中测试了硝酸盐与硝普酸钠（SNP）剂量策略的组合效果。结果表明，硝酸盐和 SNP 具有很强的协同作用，本研究中，30mg/L 硝酸盐和 20mg/L SNP 足以控制硫化物。而单独使用大量硝酸盐（100mg/L）则需要达到相同的硫化物控制效果。同时，硝酸盐与 SNP 的结合可减少 80%的有机碳源损失。此外，高通量测序结果表明，自养型、硝酸盐还原-硫化物氧化菌属（a-NR-SOB）的相对丰度增加了约 18%，如 Arcobacter 和 Sulfurimonas，而异养型、硝酸盐还原菌（hNRB）如 Thauera 则大幅减少。这表明，在硝酸盐和 SNP 投加策略下，硫化物的控制主要归因于 a-NR-SOB 的活性。微生物功能预测进一步表明，硝酸盐和 SNP 促进了异化硝酸盐还原过程，该过程将硫化物作为有效的电子供体。此外，经济评估表明，与单独添加硝酸盐相比，硝酸盐和 SNP 联合用于下水道中的硫化物控制可降低约 35%的化学成本。
