With rapidly growing industrial and economic activities, low-level pollutants, such as nitrate, urea, etc. in air, surface and ground water, have been increasing due to release of fertilizers and pesticides from industry, agriculture, and domestic sewage. It is promising to remove these pollutants and subsequently produce high-value chemicals by electrocatalysis but suffers from low efficiency. Recently, we have exploited several strategies, such as the built-in-electric field, local coordination symmetry, enhanced adsorption-separation interface and substrate geometry, to modulate the microenvironment of active sites on electrocatalysts, facilitating interfacial accumulation of the low-concentration pollutants. These have resulted in remarkable enhancement of the pollutant removal efficiency as well as improvement of yield of high-value products. In this talk, we will report our progress in separation and electrocatalytic removal of low-concentration pollutants and conversion of pollutant to high-value products.