The Effects Of Different Aeration Point To Enhanced Constructed Wetlands Treating Heavy-polluted Surface Water

As a maturing wastewater treatment model constructed wetlands has attractedworldwide interests in environmental science workers, specialists, scholars. Wetlandresearch mainly based on their different kinds of waste water purification effect at present.But under the influence of low dissolved oxygen, nitrogen and phosphorus removal rateare low in most wetlands. Microbial nitrification/denitrification from the wetland plantroots and the internal are the main factors affecting nitrogen removal. And it is consideredthat the lack of denitrification in general wetlands is main limiting reason. To solve thisproblem, the subject make contaminated water in YuJia lake as the research object, underdifferent combinations of aeration conditions to create best environmental conditions forthe different microbial nitrification/de-nitrification, use subsurface aeration waveformstrengthen wetland to study nitrogen removal and nitrogen removal mechanism by thestrengthening wetland under oxygenation.Experiment study the purification pollutants effect of four conditions aerationstrengthen wetland. And discussed the influence of plants to strengthen wetland pollutantremoval. Conclusions are as follows:1. Under four aeration mode, enhanced wetland average removal rate of COD wasnot significantly different, the average removal rates were: The backend aeration andinflow in different sides condition70.02%, the frontend aeration sides and inflow indifferent sides condition65.07%, the starting aeration and frontend side inflow condition64.65%, the points aeration and inflow in different sides condition67.36%. The frontendaeration and inflow in different sides condition average COD removal rate was71.55%after planting in wetland. Compared with ordinary artificial wetlands, COD removalefficiency is greatly improved.2. Under the backend aeration and inflow in different sides condition and the startingaeration and frontend side inflow condition, the ammonia removal rate reached a highlevel, the average removal rates were94.22%and93.21%.3. The reinforced artificial wetland has clearly different function zones of nitrationand denitrification, best effect of denitrification, and a average removal rate of32.38percent in the mode of front-end aeration and inflows of different sites. The ammonia nitrogen organic nitrogen are converted into nitric nitrogen and nitrite nitrogen in the firsthalf nitration zone,and into nitrogen which is to be desorbed in the second halfdenitrification zone.The removal rate of total nitrogen reaches41.69percent afer plantsare planted.4. Aeration enhanced wetlands on the average total phosphorus removal rate wasabout30%under several conditions. After planting, the frontend aeration and inflow indifferent sides conditions, total phosphorus average removal rate increase by the33.67%to46.23%.