Study on Percolation for Treating Dissolved Pollutants in Highway Runoff

Abstract

Although the concentration of highway runoff’s contaminants is low, highway runoff still have potential risks to the surrounding environment due to the accumulation effect. Infiltration system is a common method to control highway runoff pollution; therefore, this paper used Zn2+, P and petroleum that are typical dissolved pollutant in runoff as the target pollutants to investigate the effect of different filter materials removing highway runoff pollutants. The result shows that river sand’s removal effect is better than zeolite, in the experimental period, the efficiency of the river sand column removing Zn2+ was higher than 95%, and removal efficiency for Zn2+ of the zeolite column was higher than 90% at the first three days’ supply of Zn2+ solution, then gradually decreased. Adding a small amount of gravel was appropriate to help increase their infiltrate rate under high removal efficiency, the infiltrate rate of packed column reached 4 mm • min-1 when its mass ratio of river sand and gravel is 2:1, and its effect on the removal of pollutants was also evident. The way of water flowing through the column from its bottom to upper can help alleviate the clog of packed column.