School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China.
School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, Guangdong 510006, PR China.
Sci Total Environ. 2019 Jun 1;667:751-760. doi: 10.1016/j.scitotenv.2019.02.329. Epub 2019 Feb 22.
In this study, mechanically-dewatered sludge was used to investigate the effect of electro-dewatering (EDW) under two electrical modes, which are constant current mode followed by constant voltage mode (CV-EDW), and constant voltage mode followed by constant current mode (VC-EDW). The effect of current and voltage changes on dewatering efficiency and energy consumption of sludge electroosmosis under CV-EDW and VC-EDWs was evaluated The results show that compared with constant current mode (C-EDW), CV-EDW can improve the final dry solids content and reduce the heating rate, and the final dry solids content and unit energy consumption increase with the decrease of current and the increase of voltage. Under CV-EDW, when the dry solids content is 32%, the energy consumption can be reduced by changing to the constant voltage stage, and the energy consumption is 0.093-0.113 kWh/kg. Compared with constant voltage mode (V-EDW), VC-EDW significantly improves sludge dewatering rate. Under VC-EDW, the final dry solids content of sludge increases with the decrease of current and voltage. When the voltage is decreased by 10 V, the unit energy consumption is reduced by 27.15 ± 1.77% on average, and the energy consumption is 0.132-0.163 kWh/kg. Compared with CV-EDW, the dehydration rate of VC-EDW is increased by 72.9% on average. However, the unit energy consumption required for dehydration increases by 43.09% when the dry solids content is less than 45%.
在这项研究中，使用机械脱水污泥来研究两种电模式下的电脱水（EDW）的效果，这两种电模式分别是恒流模式后接恒压模式（CV-EDW）和恒压模式后接恒流模式（VC-EDW）。评估了 CV-EDW 和 VC-EDWs 下电流和电压变化对污泥电渗透脱水效率和能耗的影响。结果表明，与恒流模式（C-EDW）相比，CV-EDW 可以提高最终干固体含量并降低加热速率，并且最终干固体含量和单位能耗随着电流的降低和电压的升高而增加。在 CV-EDW 下，当干固体含量为 32%时，通过切换到恒压阶段可以降低能耗，能耗为 0.093-0.113 kWh/kg。与恒压模式（V-EDW）相比，VC-EDW 显著提高了污泥脱水率。在 VC-EDW 下，随着电流和电压的降低，污泥的最终干固体含量增加。当电压降低 10 V 时，单位能耗平均降低 27.15±1.77%，能耗为 0.132-0.163 kWh/kg。与 CV-EDW 相比，VC-EDW 的脱水率平均提高了 72.9%。然而，当干固体含量小于 45%时，脱水所需的单位能耗增加了 43.09%。
