Treatment and utilization of septic tank effluent using vertical-flow constructed wetlands and vegetable hydroponics.
Vertical flow constructed wetlands is a typical ecological sanitation system for sewage treatment. The removal rates for COD, BOD5, SS, TN, and TP were 60%, 80%, 74%, 49% and 79%, respectively, when septic tank effluent was treated by vertical flow filter. So the concentration of COD and BOD5 in the treated effluent could meet the quality standard for irrigation water. After that the treated effluent was used for hydroponic cultivation of water spinach and romaine lettuce, the removal efficiencies of the whole system for COD, BOD5, SS, TN and TP were 71.4%, 97.5%, 96.9%, 86.3%, and 87.4%, respectively. And it could meet the integrated wastewater discharge standard for secondary biological treatment plant. It was found that using treated effluent for hydroponic cultivation of vegetables could reduce the nitrate content in vegetables. The removal rates for total bacteria and coliform index by using vertical flow bed system with cinder substrate were 80%-90% and 85%-96%, respectively.
Cui
Li-Hua
LH
Department of Environmental Science & Engineering, South China Agricultural University, Guangzhou 510642, China. lihcui@scau.edu.cn
Luo
Shi-Ming
SM
Zhu
Xi-Zhen
XZ
Liu
Ying-Hu
YH
D017753:Ecosystem; D004755:Enterobacteriaceae; D018527:Hydroponics; D018545:Lactuca; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods*; D014872:Water Movements; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
D012722:Sewage