Study On Ecological Design And Sewage Treatment Technology Of Rural Toilet

The rural"toilet revolution"is an inevitable requirement to improve the rural living environment and change farmers’traditional health habits.It is an important part of accelerating the construction of people’s livelihood and well-being and helping the strategic layout of Rural Revitalization.With the construction of domestic rural toilets in recent years,the problems such as the inconsistency between the cost and willingness of changing toilets,the one size fits all technical standards of changing toilets,and the confusion of the construction process have become increasingly prominent.As for the implementation projects of rural toilet construction,at present,there are many phenomena,such as single rural toilet construction scheme,lack of consideration for farmers with different economic conditions and farmers in different climatic areas.This thesis studies the construction system of rural toilets facing the climate zone,in order to adapt to local conditions,and tries to establish a three-stage model of new rural toilets（basic category,perfect category and promotion category）on the premise of farmers’differentiated needs for toilet transformation.Artificial infiltration technology is used to purify the sewage of rural toilets,and different filter materials Effects of key operating parameters such as different filter depth and high hydraulic load on pollutant removal efficiency of artificial infiltration system.Based on the analysis of the adaptability of the construction of rural toilets to the climate,including the construction of short toilet doors and windows and floor slab,and the adaptability of the construction of rural toilets to the climate,including the construction of short toilet doors and windows and floor slab.Focusing on the key needs of rural toilet construction in different climate regions,this thesis defines the key points and key parameters of rural toilet construction measures for climate adaptability,puts forward the construction schemes of typical rural toilets in five climate regions,and simulates the thermal environment of typical toilet construction schemes in different climate regions by using designbuilder software,The results show that the rural toilet based on climate adaptability significantly improves the thermal comfort of the toilet house.In order to meet the differentiated needs of farmers for toilet improvement,the construction of rural toilets is classified according to the housing construction index from low to high.The construction of rural toilets is divided into basic category,perfect category and promotion category,and the corresponding relationship between the construction mode of rural toilets and the classification scheme is refined.From two aspects of toilet elements and toilet facilities,this thesis defines the design parameters and specific measures of different types of toilets,so as to provide reference for the construction of different levels of rural toilets.On the premise of price investigation,combined with the hierarchical construction method of rural toilets,the typical construction schemes of rural toilets with different levels of demand are refined.Combined with the market prices of different facilities,the construction costs of rural toilets are calculated.The costs of basic,perfect and upgraded toilets are 638～1389,2438～4628 and 6274～14115 yuan respectively,Provide reference for differentiated rural toilet construction needs.Finally,the effluent from septic tank of rural toilet is simulated and treated by multistage tidal flow constructed wetland process to study the overall operation effect of wetland system.The coarse ceramsite is selected for the primary treatment unit of tidal flow,and the activated alumina with fine particle size and best adsorption performance is selected as the filter material for the secondary treatment unit of tidal flow.The experimental results show that under the condition of high hydraulic load（1.06 m³/（m²·d））,the removal efficiencies of TP,NH₄⁺-N and COD_Crby the constructed wetland system are 86.1%,90.7%and 76.5%respectively.The concentrations of COD_Crand TP meet the pollutant discharge standard of urban sewage treatment plant（grade I A）,and the concentration of NH₄⁺-N,meets the pollutant discharge standard of urban sewage treatment plant（grade I B）;The results show that the effluent concentrations of COD_Cr,TP and NH₄⁺-N gradually decrease with the increase of the height of the filter material（activated alumina）,but the reduction rate gradually decreases with the increase of the height of the filter material.Through many experiments,the average dissolved oxygen content at each height is calculated.It is found that the dissolved oxygen gradually increases with the increase of the height of the filter material（activated alumina）.The main reason is that the water flow from top to bottom takes away the dissolved oxygen in the gap of the filter material,making the value of dissolved oxygen in the dissolved oxygen water higher;In order to further study the pollutant removal capacity of each stage of tidal biological treatment unit and the relationship between oxygen environment in the filler layer and pollutant removal,under the condition of parallel treatment of primary and secondary devices,the organic matter removal effect of effluent from different heights of activated alumina filler layer and the change of dissolved oxygen in effluent are analyzed.The results show that the concentration of dissolved oxygen in the effluent of the secondary treatment unit is higher than that of the primary unit.The high concentration of dissolved oxygen environment promotes the nitrification of nitrifying bacteria,so that the secondary unit maintains a higher removal rate of NH₄⁺-N,while the high dissolved oxygen inhibits the denitrification and increases the concentration of nitrate nitrogen in the effluent of the secondary unit.