Research On Domestic Sewage Treatment With Tidal Flow Wetland

Owing to the wastewater treatment technology of constructed wetlands is a sort of simple, convenient and effective zoology treatment technology, With the advantages of high removal capacity, simple construction, low investment, low maintenance and operation cost, simple operation and maintenance and so on. It have wide appliance foreground because the technology adapt to the wastewater treatment in country and town. But the oxygen supply in traditional constructed wetlands is limited, which affects the system performance and causes more clogging happened. The purpose of this paper is studies a new type tidal flow constructed wetlands for domestic sewage treatment, and the author studied the adsorption of wetlands plant,system startup and influencing.In this study, this thesis aims at studying the new type of tidal flow constructed wetland treating domestic wastewater. Absorption of wetland plants, tidal stream starting, affecting factors were studied.10 of the tested wetlands'emergent plants turned out to have good removal effect to warding domestic sewage, no dead during the testment. The average of each pollutant removal efficiency is NO2--H>CODcr>TP>NH4--H>NO3--H> TN. Triarrhena lutarioriparia have good removal effent to N, so it is suitable for sewage which contains high percentage of N; Colocasia tonoimo Nakai have good treatment effect on the CODc,TN, TP and NH4--H; Hedychium coronarium shows better removal efficiency on the TN, but have a worse removal effect on CODcr and TP; Ginger flower is better on TP removal efficiency, but lower on each kind of nitrogen.Size graded fillers which is used in the tester have strong adsorption capacity towarding to domestic sewage. Its adsorption capacity is different on different pollutant, CODCr> NO2--H>TN>TP>NH4--H>NO3--H. Increasing the DO in water, filler will have better absorption efficiency on of the nitrogen and phosphorus.The result of effecting factors research shows that pollutant can be degradation mostly when domestic sewage flew into bed body for 4hours, however, extend the time, there will be little effect on removal. When the bed body is empty bed for 8 hours, the effluent was the best. When the Saturation line equals with the matrix, the wetland system will have best removal efficiency. Snorkel can increase DO in the water, but the impact is limited.