Zheng Zhaozhi, Zhang Kefeng, Toe Cui Ying, Amal Rose, Deletic Ana
School of Civil and Environmental Engineering, University of New South Wales, Kensington, NSW 2052, Australia.
School of Civil and Environmental Engineering, University of New South Wales, Kensington, NSW 2052, Australia.
Sci Total Environ. 2023 Nov 10;898:166375. doi: 10.1016/j.scitotenv.2023.166375. Epub 2023 Aug 19.
Photoelectrochemical oxidation (PECO) is a promising advanced technology for treating micropollutants in stormwater. However, it is important to understand its operation prior to practical validation. In this study, we introduced a flow PECO system designed to evaluate its potential for full-scale applications in herbicides degradation, providing valuable insights for future large-scale implementations. The PECO flow reactor demonstrated the ability to treat a larger volume of stormwater (675 mL, approximately 10 times more than previous batch experiments) with effective removal rates of 92 % for diuron and 22 % for atrazine over 6 h of operation at 2 V. To address the large volume issue in stormwater treatment, a multiple module parallel application design is being considered to increase the treatment capacity of the PECO flow reactor. During the flow reactor operations, flow rate was found to have a notable impact on removal performance, particularly for diuron. At a flow rate of 610 mL min, approximately 90 % removal of diuron was achieved, while at 29 mL min, the removal efficiency decreased to 60 %. While light intensity had minimal effect on diuron degradation (all settings achieved over 90 % removal), it enhanced atrazine degradation from 9 % to 31 % with an increase in intensity from 63 mW cm to 144 mW cm. Remarkably, the PECO flow system exhibited excellent removal performance (>90 % removal) for diuron even at extremely high initial pollutant concentrations (240 μg L), demonstrating its capacity to handle varying contaminant loads in stormwater. Energy consumption analysis revealed that flow rate as the primary factor influenced the specific energy consumption rate. Higher flow rate (e.g., 610 mL min) were preferable in flow reactor due to its well-balanced performance between removal and energy consumption. These findings confirm that the PECO flow system offers an efficient and promising approach for stormwater treatment applications.
光电化学氧化（PECO）是一种用于处理雨水中微污染物的很有前景的先进技术。然而，在实际验证之前了解其运行情况很重要。在本研究中，我们引入了一种流动PECO系统，旨在评估其在除草剂降解方面大规模应用的潜力，为未来的大规模实施提供有价值的见解。PECO流动反应器展示了处理更大体积雨水（675毫升，约为之前批次实验的10倍）的能力，在2伏电压下运行6小时，敌草隆的有效去除率为92%，莠去津的有效去除率为22%。为了解决雨水处理中的大体积问题，正在考虑采用多模块并行应用设计来提高PECO流动反应器的处理能力。在流动反应器运行期间，发现流速对去除性能有显著影响，特别是对敌草隆。在流速为610毫升/分钟时，敌草隆的去除率约为90%，而在29毫升/分钟时，去除效率降至60%。虽然光强度对敌草隆降解的影响最小（所有设置下的去除率均超过90%），但随着光强度从63毫瓦/平方厘米增加到144毫瓦/平方厘米，莠去津的降解率从9%提高到31%。值得注意的是，即使在初始污染物浓度极高（240微克/升）的情况下，PECO流动系统对敌草隆仍表现出优异的去除性能（去除率>90%），证明了其处理雨水中不同污染物负荷的能力。能耗分析表明，流速是影响比能耗率的主要因素。在流动反应器中，较高的流速（例如610毫升/分钟）更可取，因为其在去除和能耗之间具有良好的平衡性能。这些发现证实，PECO流动系统为雨水处理应用提供了一种高效且有前景的方法。
