Study On Upland Constructed Wetland

As an ecotypic technique for wastewater treatment, constructed wetland has more virtues in contrast of other techniques. For example, it's structure is simple, the cost of building and running is low, it has a good adaptability to fit changeful circumstances, and the water quality of the effluent is steady. Therefore, constructed wetland may have a good develop perspective in wastewater treatment and eutrophication control. However, it also has some shortcoming, such as a bigger floor area and shortage of dissolved oxygen in wetland etc. Moreover, the construction of traditional process sewage treatment plants will be expensive due to the disadvantage of mountainous, lack of arable land and dispersive towns in three gorges reservoir area.As a result,"upland constructed wetland"is put forward. It can save lots of arable land by means of building wetland on the hillside of the uplands (angle of slope is bigger than 25 degree). It can also bring enough dissolved oxygen by hydraulic drop. A new technique of wastewater treatment named simple anaerobic pond plus hydraulic drop wavy subsurface constructed wetland("SAP and DWSCW"for short), is put forward in this paper.First of all, a high hydraulic load experiment is finished. The experimental results shows that CODcr removal efficiency can reach 70%~80%, and the value of CODcr can be reduced from above 300 mg/l to below 100 mg/l when operated with high hydraulic load. In the concrete: removal efficiency of SP(soluble phosphorus)and NH4+-N are between 30% and 40% when hydraulic load is 90 cm/d. The top value removal efficiency of SP, TP and NH4+-N are 56%, 63% and 55% respectively when hydraulic load is 50 cm/d. Pollutant removal efficiency rised when hydraulic load is reduced.Secondly, correlation between some working parameters and pollutant removal efficiency is analyzed. Moreover, some parameters that may influence the pollutant removal are analyzed too. The conclusion shows that correlation between pollutants removal rate and pollutant burden are positive, the organic removal character in accordance with mixed order kinetics, and the correlation between hydraulic load and pollutant removal efficiency is negative.Thirdly, according to the experiment conclusion, characteristics of the new process are analyzed in detail. It is conclude that the aerate effects of hydraulic drop of the...