Zhejiang Key Laboratory of Drinking Water Safety and Distribution Technology, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058, PR China; Department of Civil Engineering, The University of Hong Kong, 999077, Hong Kong, China.
Zhejiang Key Laboratory of Drinking Water Safety and Distribution Technology, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058, PR China.
Chemosphere. 2021 Oct;280:130618. doi: 10.1016/j.chemosphere.2021.130618. Epub 2021 Apr 27.
Currently, seawater desalination based on air-water interface solar heating has triggered significant research interests because it effectively makes use of the solar energy and avoids fossil fuel consumption. However, to prevent the volatile organic compounds (VOCs) from volatilizing with water vapor which later will liquefy and enter the condensed freshwater is still a challenge. In this work, a g-CN/MoS based floating solar still (CM-FSS) combined with thermal/light activation of persulfate (PS) at air-water interface was applied for clean freshwater production for the first time. The CM-FSS was composed of a g-CN/MoS top layer for solar absorption, simultaneous thermal/light activation of PS and then VOCs degradation at air-water interface, a floating layer of expandable polyethylene (EPE) foam for heat isolation, and a transport channel of air-laid paper (ALP) for seawater and PS solution delivery. The water evaporation rate of the CM-FSS was measured at 1.23 kg m h under 1 kW m, which is 4.09 times higher than that of pure water without an evaporator. With the assistance of g-CN/MoS photocatalytic degradation and thermal/light activation of PS at the air-water interface, a high removal efficiency of a selected model VOCs pollutant of nitrobenzene (NB) could reach to 98.2% in condensed freshwater. Finally, when real seawater samples were employed as source water for solar distillation, the typical water-quality indices such as salinity, turbidity, anions, cations and organics of the condensed freshwater were below the limit values of the Standards for Drinking Water Quality in WHO, US EPA and China.
目前，基于气-水界面太阳能加热的海水淡化技术引起了广泛关注，因为它有效地利用了太阳能并避免了化石燃料的消耗。然而，防止挥发性有机化合物（VOCs）随水蒸气挥发，随后液化并进入冷凝淡水，仍然是一个挑战。在这项工作中，首次应用了基于 g-CN/MoS 的浮式太阳能蒸馏器（CM-FSS），该系统在气-水界面结合了过硫酸盐（PS）的热/光活化，以生产清洁的淡水。CM-FSS 由 g-CN/MoS 顶层组成，用于太阳能吸收，同时在气-水界面进行 PS 的热/光活化以及 VOCs 的降解，由可膨胀聚乙烯（EPE）泡沫组成的浮层用于隔热，以及空气铺设纸（ALP）输送通道用于海水和 PS 溶液的输送。在 1kW·m 下，CM-FSS 的水蒸发速率为 1.23kg·m h ，比没有蒸发器的纯水高 4.09 倍。在 g-CN/MoS 光催化降解和 PS 在气-水界面的热/光活化的辅助下，选定的模型 VOCs 污染物硝基苯（NB）的去除效率高达 98.2%。最后，当实际海水样品作为太阳能蒸馏的水源时，冷凝淡水的典型水质指标，如盐度、浊度、阴离子、阳离子和有机物，均低于世界卫生组织、美国环保署和中国《生活饮用水卫生标准》的限值。
