120 / 2017-06-16 17:15:07

Research on pollutants removal efficiency of bioretention in red soil region in southern China

bioretention; removal efficiency; local plant; red soil; Principal component analysis

As one of the main technologies of low impact development (LID), bioretention(BR) can effectively control the non-point source pollution caused by urban runoff, but lacks experimental study of it native suitability in China. Plants and soil layer are main components of bioretention, in order to study the influence of removal efficiency of pollutants in runoff by both, according to local urban runoff characteristics, choose different plants and ratio of sand/soil design five medium-size simulator, and eight times synthetic runoff simulation experiment were carried out. The results showed: All BRs average removal efficiency of Cu, Pb, Zn, Cd, TP, ammonia, nitrate, TN and COD were more than 86.53%, 92.86%, 95.73%, 95.06%, 79.10%, 57.65%, 71.33%, 65.10% and 59.16%, respectively, and outflow concentrations of pollutants(except COD) were meet the surface water environmental quality standard. Four principal component of pollutants were ammonia and TN, Zn and Cd, Cu and COD, Pb, respectively. The BR-A and BR-E(plant Rosa Chinensis, ratio of sand/soil in soil layer were 1:4 and 1:5) had the best and worst pollutants removal performance. Plant species and ratio of sand/soil in soil layer had no significant effect in removal efficiency of pollutants(except nitrate). This study provide theory basis and reference for design and application of bioretention in southern red soil area.