Study On The Effect Of Substrates And Aquatic Plants On The Treatment Of Domestic Sewage

Sewage ecological treatment system is closely related to the concepts of sustainable/harmonious-green development,rational resource development,and ecological protection priority.To achieve low cost,easy management and no secondary pollution in the process treating domestic wastewater,the rational selection of local aquatic plants and the optimal combination of natural sediments are particularly important based on Sewage ecological treatment system.In this paper,five species of aquatic plants commonly found in northern China are selected: Lythrum salicaria,Acorus calamus,Phragmites australis,Typhaorientalis presl,Nelumbo nucifera,and six substrates: sand.,Stone,furnace ash,sand + soil,stone + soil,furnace ash + soil as the research material,pot experiments,through the measurement of the growth indicators of aquatic plants and physical and chemical indicators of water quality in domestic sewage,to compare the matrix and Effects of Aquatic Plants on the Restoration of Rural Domestic Sewage.The test results show that:(1)After the sewage ecological treatment system,various water quality physical indicators have obvious improvement effects,and different substrates and aquatic plants have different effects on the improvement of different water quality physical indicators.The average removal rate of CODMn by five aquatic plants was as follows: Typha orientalis(85%)> Phragmites australis(77%)> Iris pseeudacoru(66%)> Nelumbo nucifera(63%)> Lythrum salicarria L.(59%);The average removal rate of TP was as follows: Typha orientalis(85%)> Phragmites australis(76%)> Iris pseeudacoru(71%)> Nelumbo nucifera(69%)> Lythrum salicarria L.(61%);The average removal rate of TN was Typha orientalis > Phragmites australis > Iris pseeudacoru > Lythrum salicarria L.> Nelumbo nucifera,the removal rates were 83%,77%,69%,58%,53%.Furnace ash has the highest removal rate of domestic wastewater pollutants,and the removal rates of CODMn,TN and TP were 71%,69% and 74%,respectively.(2)There is a significant correlation between conductivity and COD and TP.The regression equation of conductivity and COD is: y=-0.4782x+1455.4,and the regression equation of conductivity and TP is: y=-61.072x+1537.There is a significant correlation between turbidity and COD,TN and TP.The regression equation of turbidity and COD is: y=0.0836x+18.554.The regression equation of turbidity and TN is: y=0.6575x+21.168,turbidity and The regression equation for TP is: y=5.0504x+18.073.There is a significant correlation between dissolved oxygen and COD.The regression equation for dissolved oxygen and COD is: y=-0.0039x+2.2303.Rapid measurement of certain chemical indicators can be achieved through the correlation of physical and chemical indicators.(3)The paper determined the influence factors by evaluating the Removal capacity of various combinations under the same influent conditions during the experimental period.The paper provided a basis for the research on the optimal pollutants’ removal efficiency based on Sewage ecological treatment system.Cattail and furnace ash have the highest removal rate of pollutants in the sewage,and the suitable matrix-aquatic plant combination is furnace ash-cattail.