Acoustic cavitation assisted plasma for wastewater treatment: Degradation of Rhodamine B in aqueous solution
Acoustic cavitation assisted plasma for wastewater treatment: Degradation of Rhodamine B in aqueous solution
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DOI：
10.1016/j.ultsonch.2018.12.003
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发表时间：
2019-04-01
影响因子：
8.4
通讯作者：
Komarov, Sergey
中科院分区：
文献类型：
--
作者：
Fang, Yu;Hariu, Daiki;Komarov, Sergey
提出了一种新的废水处理工艺--声空化辅助等离子体(ACAP)，旨在通过超声辐射和高压等离子体放电的协同作用，扩大水污染物的可处理范围。在这一过程中，声空化的作用不仅是提供化学活性的OH中心点自由基的产生，例如在传统的超声波废水处理技术中，而且还确保了废水中稳定的等离子体产生的条件，从而扩大了水污染物的可处理范围。以罗丹明B(RhB)为模型污染物，考察了超声幅值、RhB初始浓度、输出电压、溶液pH和电导率对RhB降解效率的影响。结果表明，超声辅助等离子体产生需要较低的输出电压，并允许将可处理溶液的可接受电导率范围提高到1000亩S/厘米，约为常规等离子体放电处理的24倍。碱性和酸性介质有利于较高的降解效率。最近有关水下等离子体的其他测量和研究结果表明，空化区中存在的微气泡可以作为“桥梁”，使脉冲放电在电极之间的传播比传统情况下更容易。此外，声空化有助于等离子体放电更快地从无效流光放电过渡到更有效的火花放电，从而进一步提高处理性能。
A novel wastewater treatment process, acoustic cavitation assisted plasma (ACAP) is proposed in this study aiming at expanding the treatable range of water pollutants due to a synergetic effect of ultrasound irradiation and high voltage plasma discharge. In this process, the role of acoustic cavitation is not only to provide generation of chemically active OH center dot radicals, as for example in conventional ultrasonic wastewater treatment techniques, but also to ensure conditions for stable plasma generation in wastewater and, thus, to extend the treatable range of water pollutants. Rhodamine B (RhB) was used as a model pollutant in experiments examining effects of ultrasound amplitude, RhB initial concentration, output voltage, solution pH and electrical conductivity on the RhB degradation efficiency. The results revealed that the ultrasound-assisted plasma generation requires lower output voltages and allows to increase the acceptable range of electrical conductivity of treatable solutions up to 1000 mu S/cm, that is about 24 times higher than in the case of conventional plasma discharge treatment. The alkaline and acid medium were found to be favorable for higher degradation efficiency. Additional measurements and results of recent investigations concerning underwater plasma showed that microbubbles presented in cavitation zone could serve as "bridges" making the pulse discharge propagation between the electrodes easier than in the conventional case. Besides, acoustic cavitation assists a faster transition of plasma discharge from ineffective streamer type to more effective spark type that further contributes to the improvement of the treatment performance.