Environmental Science Program, University of Idaho, Moscow, USA.
Department of Chemical and Biological Engineering, University of Idaho, Moscow, USA.
Environ Technol. 2023 Nov;44(25):3911-3925. doi: 10.1080/09593330.2022.2077131. Epub 2022 May 19.
Diminishing phosphorus resources worldwide requires developing new technologies to recover phosphorus (P) from wastewaters. A lab-scale electrolytic reactor with a magnesium anode was investigated to remove NH and PO from synthetic wastewater by producing struvite. The effects of mixing speed, pH, and applied current on struvite yield, NH, and PO removal efficiencies were first evaluated using a factorial design. Then, the two most significant parameters were further optimized using Central Composite Design (CCD) coupled with Response Surface Methodology (RSM). The struvite was characterized by SEM, XRD, and FT-IR. A 5.7-fold increase in struvite yield was achieved by increasing the applied current from 0.1 to 0.5 A. The three regression equations generated by the CCD/RSM design with applied current and mixing speed as the two independent parameters were highly correlated with the response variables (struvite yield, NH and PO removal efficiencies). The desirability analysis showed the best operating condition: current, 0.5 A and mixing speed, 414 rpm, for the reactor system, under which the optimal struvite yield and NH and PO removal efficiencies were 4.75 g/L, 93.0%, and 58.4%, respectively. The SEM, XRD, and FT-IR analyses confirmed the high purity and quality of the struvite produced by the electrolytic reactor system.
全球磷资源的减少要求开发新技术从废水中回收磷 (P)。本研究采用带有镁阳极的实验室规模电解槽，通过生成鸟粪石来去除合成废水中的 NH 和 PO。首先采用析因设计评估了混合速度、pH 和施加电流对鸟粪石产率、NH 和 PO 去除效率的影响。然后，使用中心复合设计 (CCD) 结合响应面法 (RSM) 进一步优化了两个最重要的参数。通过 SEM、XRD 和 FT-IR 对鸟粪石进行了表征。通过将施加电流从 0.1 A 增加到 0.5 A，鸟粪石产率提高了 5.7 倍。通过 CCD/RSM 设计生成的三个回归方程，将施加电流和混合速度作为两个独立参数，与响应变量（鸟粪石产率、NH 和 PO 去除效率）高度相关。通过理想性分析得到最佳操作条件：电流为 0.5 A，混合速度为 414 rpm，在此条件下，最佳鸟粪石产率、NH 和 PO 去除效率分别为 4.75 g/L、93.0%和 58.4%。SEM、XRD 和 FT-IR 分析证实了由电解槽系统生成的鸟粪石具有高纯度和高质量。
