Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore.
Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
J Hazard Mater. 2020 Jun 5;391:122219. doi: 10.1016/j.jhazmat.2020.122219. Epub 2020 Feb 2.
A novel, recyclable, and rapid pre-ultrasound-thermal-acid-washed zero valent scrap iron/hydrogen peroxide (UTA-ZVSI/HO) method has been developed to effectively enhance waste activated sludge (WAS) dewaterability. The effects of UTA ultrasound densities, UTA temperature, newly generated iron solution, HO concentrations, and WAS conditioning time on the WAS dewaterability were investigated using a bench-scale system. Results indicated that the UTA-ZVSI/HO treatment significantly improved the WAS dewaterability. The water content of the dewatered cake decreased to 44.15 ± 0.98 wt% during optimal operational conditions, which was significantly lower than that achieved using Fenton-based processes. Based on this outcome, a three-step treatment mechanism involving UTA-ZVSI/HO has been developed, including iron flocculation, hydroxyl radical oxidation, and skeleton building. The dewatering efficiencies of three types of representative WAS were consistently effective in the UTA-ZVSI/HO reactor for up to 15 cycles. Efficiencies levels were significantly higher than those achieved with Fenton-based processes. Economic analysis illustrated that the developed UTA-ZVSI/HO system was the most cost-effective among other WAS dewatering treatments. In addition, the treatment system significantly alleviated toxicity of heavy metals and phytotoxicity in the dewatered sludge. This supported subsequent agricultural use. In summary, this study provided a comprehensive and useful basis for improving WAS dewatering and subsequent disposal.
一种新颖、可回收且快速的超声-热酸预处理零价铁/过氧化氢（UTA-ZVSI/HO）方法已被开发出来，以有效增强废活性污泥（WAS）的脱水性能。使用实验室规模的系统研究了 UTA 超声密度、UTA 温度、新生成的铁溶液、HO 浓度和 WAS 调理时间对 WAS 脱水性能的影响。结果表明，UTA-ZVSI/HO 处理显著改善了 WAS 的脱水性能。在最佳操作条件下，脱水饼的水分含量降低至 44.15±0.98wt%，明显低于基于芬顿工艺的处理方法。基于这一结果，提出了一个三步处理机制，包括铁絮凝、羟基自由基氧化和骨架构建。在 UTA-ZVSI/HO 反应器中，三种代表性 WAS 的脱水效率在 15 个循环内始终有效。效率水平明显高于基于芬顿工艺的处理方法。经济分析表明，与其他 WAS 脱水处理方法相比，所开发的 UTA-ZVSI/HO 系统是最具成本效益的。此外，该处理系统显著减轻了脱水污泥中重金属的毒性和植物毒性。这支持了随后的农业用途。总之，本研究为改善 WAS 脱水和后续处置提供了全面有用的基础。
