Abstract: In this paper, low-load compound paddy field submersible wetland was used as the main test process, and the method of using the bacteria fortified with rice field wetland to purify village sewage, studied the removal efficiency of the target pollutants in the paddy field wetland under the strengthening of fungi, and analyzed the migration law of dissolved organic compounds in the process of biodegradation. The results showed that after adding B8 bacteria to the subsurface flow wetland in paddy field for 14 consecutive days, during the operation of the device, the average removal rate of total phosphorus, ammonia nitrogen and total nitrogen in wetland system was 91%, 91.34% and 89.22% respectively, which increased by 6.4, 10 and 16.22 percentage points respectively, the average removal rates of COD and UV₂₅₄ were 68% and 70%, which were 8 and 11 percentage points higher than that of the control group. The average effluent concentration was 31.09 mg/L and 0.08. The removal efficiency of wetland system to chlorophyll was good. The removal rate of the group with and without bacteria is 90%, and the average effluent concentration was 2.35 μg/L, the effluent all reached the class IV standard in the environmental quality standard for surface water （GB3838—2002）, which indicated that the B8 fungicide had synergistic effect on the removal of nitrogen, phosphorus and organic matter in the river water of the village. Through the three-dimensional fluorescence measurement of sewage, it was found that the main component of organic matter in the water was DOM, most of which comes from algae cells in the influent and humic substances in the village drainage, mainly through the cooperation of plants and microorganisms in the paddy field area to achieve the removal.

Key words: cultivated wetlands, denitrifying polyphosphate-accumulating organisms, biodegradation, nitrogen and phosphorus removal