Nitrogen removal characteristics of wet–dry alternative constructed wetlands

Abstract

Abstract Dry–wet alternate constructed wetland is an effective method to remove nitrogen elements in the tail water of sewage treatment plant. According to the reaeration mechanism of wet–dry alternative constructed wetland, the denitrification effect and influence characteristics of the dry–wet alternate constructed wetland on the tail water of sewage treatment plant were studied under low temperature. The results showed that the removal rates of each nitrogen element in the constructed wetland reached 20–40% with the dry–wet alternate time at 10°C. Under the influence of dry–wet alternation of constructed wetland, dissolved oxygen (DO) was significantly correlated with the dry–wet alternation time (p < 0.05), and DO was correlated with each nitrogen element removal rate (p < 0.05), which means constructed wetlands use alternate dry and wet operation, which can significantly affect the content of DO and nitrogen removal efficiency in constructed wetlands, providing a technical basis for regulating the operation effect of constructed wetland ecosystems.