Abstract
An experiment of wastewater treatment was conducted using G, C and E type trench set in three lysimeters in which volcanic ash soil was packed. The main object of this research was to evaluate the behavior of wastewater permeation and the removal efficiency of wastewater in soil, and the following results were obtained.
1) The declining velocity of water level in G, C and E type trench was 11, 4.0 and 1.7 mm·min-1, respectively.
2) The discharging ratio of soil water from the lysimeter against the volume loaded to the one was 96.6, 84.2 and 73.8% in G, C and E type trench, respectively.
3) The amount of evapotranspiration in G, C and E type trench was 5.1, 6.4 and 11.7 mm·d-1, respectively.
4) The removal efficiency of BOD, COD, NH4-N and TP in wastewater was more than 90% in G, C and E type trench.
5) The removal efficiency of TN in wastewater was 27.442.5%, and the value was highest in E type trench.
