A self-powered electro-coagulation system afforded by flexible electromagnetic flag wind generators for efficient removal of arsenic from water

In the past few years, human activities , such as mining and metallurgical industries , have made the arsenic concentration in natural waters elevate. To provide clean and safe water to people worldwide, tremendous endeavors have been made to accomplish low-cost and effective treatment of arsenic-containing water. Among the methods employed, electro-coagulation has been the one that stands out attributable to its high efficiency and low cost. However, its high energy consumption has become an obstacle to further applications, particularly in the regions where electricity is limited. Here, an innovative self-powered electro-coagulation system (SPECS) driven by flexible electromagnetic flag wind generators (FEFWGs) is developed to realize the power-free removal of dissolved arsenic in water. The FEFWGs exhibit an excellent output performance under a moderate wind speed (6.3 m s −1 ), with a peak open-circuit voltage of 3.7 V and a peak short-circuit current of 13.6 mA. Using the SPECS to purify polluted water, a large volume of wastewater containing 5 ppm of arsenic can be purified with our SPECS in 20 min, which is more efficient than that of existing reports.