Field engineering application of agricultural farmland surface runoff pollution treatment by combined bioreactor and constructed wetlands

Agricultural non-point pollution is the biggest source in China from 2009, treatment of agricultural surface runoff very important to mitigate eutrophication rivers and lakes because one key type pollution. In this study, farmland Chengdu Plain was treated for year (2017 ~ 2018) by combination technology new material (waste fir Hemlock sawdust as substrate) bioreactor denitrification Vertical-flow Constructed Wetland (VFCW, planting Cyperus alternifolius L.) combining zeolite Lanthanum-modified activated Alumina (γ-Al2O3) absorption agent dephosphorization. This engineering application successively joint three processes (sedimentation unit → dephosphorization unit) with 5 paralleling groups. The results show that average removal rate total nitrogen (TN) phosphorus (TP) at (filled sawdust) were 29.64% 66.56%, respectively. TP VFCW γ-Al2O3 60.44%, while it 51.66% without γ-Al2O3. better than both hemlock mixed hemlock-fir bioreactor. Overall, filling some best treatment.