School of Environmental Science and Engineering, Huazhong Unviersity of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, China.
Hubei Meichen Environmental Protection Science and Technology Co., Ltd., No. 6 Gaoxin Road, High-tech Zone, Jingmen, 448000, China.
Sci Rep. 2019 Jun 20;9(1):8893. doi: 10.1038/s41598-019-45085-3.
Struvite precipitation electrolyzers are interesting environmental electrochemical reactors with potential applications for efficient phosphate recovery from wastewater, such as swine wastewater. In this paper, effects of phosphate concentration and pH on the struvite precipitation reaction rate were investigated. When phosphate concentration decreased from 100 to 20 mg/L, the precipitation reaction rate decreased from 396.65 mg/L·h to 70.46 mg/L·h, indicating that the reaction rate of struvite crystallization can be controlled by adjusting pH according to the change of phosphate concentration. Numerical simulation of different currents and flow rates on pH in the electrolyzer was developed and validated, and pH in the electrolyzer was dynamically measured along the distribution point of the flow field. We aimed to test the treatment effect of the electrolyzer on actual swine wastewater. When the flow rate was 20 L/h and constant voltage was 4 V, the electrolyzer was run continuously for 5 hours with the volume of 50 L. The phosphate recovery efficiency reached 99.51%, and the time-space yield of the struvite precipitation electrolyzer was 0.0219 kg/m2·h. The harvested struvite particles were identified by XRD and SEM-EDS, which presented orthorhombic structure and high purity. Economic analysis demonstrated that the proposed electrolyzer was cost-effective and technologically convenient.
鸟粪石沉淀电解槽是一种有趣的环境电化学反应器，具有从废水中高效回收磷酸盐的潜在应用，如猪废水。本文研究了磷酸盐浓度和 pH 值对鸟粪石沉淀反应速率的影响。当磷酸盐浓度从 100 降至 20mg/L 时，沉淀反应速率从 396.65mg/L·h 降至 70.46mg/L·h，表明可以根据磷酸盐浓度的变化通过调节 pH 值来控制鸟粪石结晶的反应速率。开发并验证了不同电流和流速对电解槽中 pH 值的数值模拟，并沿流场分布点动态测量了电解槽中的 pH 值。我们旨在测试电解槽对实际猪废水的处理效果。当流速为 20L/h 且恒压为 4V 时，电解槽以 50L 的体积连续运行 5 小时。磷酸盐的回收率达到 99.51%，鸟粪石沉淀电解槽的时空产率为 0.0219kg/m2·h。通过 XRD 和 SEM-EDS 对收获的鸟粪石颗粒进行了鉴定，呈现出正交结构和高纯度。经济分析表明，所提出的电解槽具有成本效益和技术便利性。
