Enhanced Treatment of Decentralized Domestic Sewage Using Gravity-Flow Multi-Soil-Layering Systems Coupled with Iron-Carbon Microelectrolysis

Soil-based decentralized treatment technology has become increasingly popular as an ideal solution for water pollution control in rural areas. It is very necessary to optimize the removal mechanisms and performance of such technologies on domestic sewage treatment. This was first study a gravity-flow multi-soil-layering (MSL) system coupled with iron-carbon microelectrolysis (ICM). Influent COD/TN (C/N) ratio bottommost soil mixture block (SMB) submersion were selected operating factors relevant ICM MSL systems. Such two key investigated factorial experiment. The efficiencies COD, TP, NH3-N, NO3?-N, TN could be reached up 96.3, 100, 95.4, 93.8, 79.6%, respectively. Different levels comprehensively drive variation. analysis indicated that SMB had most significant dominant negative effects aerobic processes. TP attributed presence submersion. played role facilitating electrochemical reaction through ICM. Zero-valent iron or ferrous ions transformed final ferric more efficiently during period reactions. promote capability removing nutrients sewage, especially provide electron donors denitrifying bacteria However, there non-significant influent C/N can help enrich pollutant