Study On Treatment Of Domestic Sewage With Anaerobic Baffle Reactor-subsurface Flow Wetland And Denitrification Mechanism

In this thesis, using the combination process of anaerobic baffle reactor (ABR)-subsurface flow wetland (SSFW) to treat domestic sewage and denitrification mechanism were studied. Three parts were included in this paper:the start of combination process, the effect of using the combination process to treat domestic sewage, denitrification mechanism.1. The start of combination process was studied.The start of combination process is divided into the start of ABR and the start of SSFW. In the start stage, the temperature is range of14-26℃and the hydraulic retention time (HRT) of initial ABR is48h.The removal rate of COD steady at80%above marks the start success. After78days of operation, ABR startup success.After about60days, COD in effluent keep concentrations below50mg/L and the removal rate of SS steady at90%or more. At this time, when the plant began to grow faster, the start of SSFW completed.2. The effect of using the combination process to treat domestic sewage was studied.Comprehensive consideration, the best flow of combination process was1.08m3/d. When flow for1.08m3/d, total removal rate of COD is84.73%and effluent concentrations is40.43mg/L, Standard A of Sewage Discharge Level was qualified; When flow for1.08m3/d, total removal rate of TN is58.36%and effluent concentrations is17.70mg/L, Standard B of Sewage Discharge Level was qualified; When flow for1.08m3/d, total removal rate of NH3-N is53.8%and effluent concentrations is14.22mg/L, Standard Ⅱ of Sewage Discharge Level was qualified; When flow for1.08m3/d, total removal rate of TP is77.39%and effluent concentrations is0.45mg/L, Standard A of Sewage Discharge Level was qualified. Due to combination process for SS have very strong impact resistance ability, so the highest removal rate is98.72%and the lowest removal rate is90.56%. The pH in effluent of combination process tend to be neutral.3. denitrification mechanism.The role of wetland plants is one of the absorption of nitrogen. The experiment studied that the removal of nitrogen by typha latifolia make up only10.46%. It’s not the major way to denitrification. The total nitrogen content of roots, stems, leaves, from the great to the little, was Leaf, roots, stems.