The objective of this study was to evaluate the effects of Ni(II) and Cr(VI) individually and in combination on the simultaneous removal of chemical oxygen demand (COD), nitrogen and metals under a sequencing batch reactor (SBR) operation. Three identical laboratory-scale SBRs were operated with FILL, REACT, SETTLE, DRAW and IDLE periods in a ratio of 1:12:1:2:8 for a cycle time of 24 h until the steady state was achieved. Nickel(II) at increasing concentrations up to 35 mg/L was added to one of the reactors; Cr(VI) at increasing concentrations up to 25 mg/L was added to a second reactor; while a combination of Ni(II) and Cr(VI) in equal concentrations up to 10 mg/L was added to a third reactor. The results demonstrate that both Ni(II) and Cr(VI) exerted a more pronounced inhibitory effect on the removal of ammonia nitrogen (AN) than on COD removal. Synergistic and antagonistic inhibitory effects on the rates of COD and AN removal, respectively, were observed for the 50% Ni(II) and 50% Cr(VI) (w/w) mixture in the concentration range between 10 and 20 mg/L. The simultaneous presence of 50% Ni(II) and 50% Cr(VI) at a concentration of 20 mg/L resulted in system failure.

中文翻译：

---

镍(II)和铬(VI)对序批式反应器需氧量、脱氮和金属去除的影响

本研究的目的是评估 Ni(II) 和 Cr(VI) 单独和组合对在序批式反应器 (SBR) 操作下同时去除化学需氧量 (COD)、氮和金属的影响。三个相同的实验室规模的 SBR 以 1:12:1:2:8 的比例以 1:12:1:2:8 的比例运行填充、反应、沉淀、拉伸和空闲周期，循环时间为 24 小时，直到达到稳态。将浓度增加至 35 mg/L 的镍 (II) 添加到其中一个反应器中；将浓度增加至 25 mg/L 的 Cr(VI) 添加到第二个反应器中；而将 Ni(II) 和 Cr(VI) 的组合以高达 10 mg/L 的等浓度添加到第三个反应器中。结果表明，Ni(II)和Cr(VI)对氨氮(AN)的去除作用比对COD的去除作用更显着。对于浓度范围在 10 到 20 mg/L 之间的 50% Ni(II) 和 50% Cr(VI) (w/w) 混合物，分别观察到对 COD 和 AN 去除率的协同和拮抗抑制作用. 同时存在浓度为 20 mg/L 的 50% Ni(II) 和 50% Cr(VI) 会导致系统故障。