College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua 321004, China.
College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China.
Bioresour Technol. 2023 Sep;384:129271. doi: 10.1016/j.biortech.2023.129271. Epub 2023 Jun 7.
Stainless steel is highly valued for its superior resistance to corrosion. However, the pickling process involved in stainless steel production generates abundant NO-N, causing health and environmental risks. To address this issue, this study proposed a novel solution utilizing an up-flow denitrification reactor and denitrifying granular sludge for treating NO-N pickling wastewater under high NO-N loading. It was found that, the denitrifying granular sludge exhibited stable denitrification performance with the highest denitrification rate of 2.79 gN/(gVSS·d) and average removal rates of NO-N and TN of 99.94% and 99.31%, respectively, under optimal operating conditions of pH 6-9, temperature 35 °C, C/N ratio 3.5, hydraulic retention time (HRT) 11.1 h and ascending flow rate 2.75 m/h. This process reduced carbon source usage by 12.5-41.7% as compared to traditional denitrification methods. These findings demonstrate the efficacy of combining granular sludge and an up-flow denitrification reactor for treating nitric acid pickling wastewater.
不锈钢因其优异的耐腐蚀性而备受重视。然而，不锈钢生产中的酸洗过程会产生大量的硝态氮，对健康和环境造成风险。为了解决这个问题，本研究提出了一种利用上流式反硝化反应器和反硝化颗粒污泥在高硝态氮负荷下处理硝酸酸洗废水的新方法。研究发现，反硝化颗粒污泥具有稳定的反硝化性能，在最佳运行条件下（pH 值为 6-9、温度为 35°C、C/N 比为 3.5、水力停留时间为 11.1 小时和上升流速为 2.75 米/小时），反硝化速率最高可达 2.79 gN/(gVSS·d)，硝态氮和总氮的平均去除率分别达到 99.94%和 99.31%。与传统的反硝化方法相比，该工艺可减少 12.5-41.7%的碳源使用。这些发现表明，将颗粒污泥和上流式反硝化反应器相结合处理硝酸酸洗废水是有效的。
