Optimization Of Septic Storage System Based On Environmental Safety And Resource Utilization

As farmers yearn for a better life,the"toilet revolution"is vigorously promoted.The three-cell septic toilet with water flushing characteristics has become the most common type of toilet,which can realize the harmless treatment of manure and support the resource utilization of manure.The country has promulgated the construction and maintenance standards for three-cell septic tank toilets(GB/T38836-2020,GB/T38837-2020),which requires that"washing,kitchen sewage,and other domestic miscellaneous drainages should not be discharged into septic tanks"and give A"three-part septic tank effective volume table"based on the number of toilet users was developed.However,the survey found that the indoor drainage pipes of rural houses have not yet realized the collection of gray and black water flow.The inspection and acceptance of the toilet modification project are only carried out according to the standard integrated three-cell septic tank volume(1.5 m~3～2 m~3).The current norms approve the unity of the septic tank volume based on the number of people.They do not adapt to and match the diverse scenarios of rural water and sewage collection methods,resulting in a widespread overflow of septic tanks.Difficult to realize its unique harmless and resource utilization.Based on the above problems,this paper proposes a set of optimization schemes for septic storage systems based on environmental safety and resource utilization,which provides the theoretical basis and technical guidance for constructing septic tank toilets in rural toilets.First of all,this paper analyzes the three collection methods of household sewage in the courtyard of farmers and the two types of toilet flushing water volume,constructs six typical sewage collection scenarios,and calculates the sewage collection volume of septic tanks under the six scenarios.Following the minimum 30-day residence time requirement for the harmlessness of the septic tank,the volume of the harmlessness of the septic tank was approved to ensure that the waste in the septic tank meets the requirements for harmlessness and sanitation.Second,analyze the fertilizer characteristics of the effluent from the septic tank and clarify the effluent treatment and disposal methods of the septic tank.Separate collection scenarios A and D of septic tank effluent fertilizers are of higher value.By analyzing crop fertilizer requirements and fertilization seasonal characteristics in typical areas,90 days are used as the most prolonged period of agricultural fertilization.The calculation based on the utilization of manure resources is calculated.The storage volume of septic tanks is encouraged to use 1/2 L water-saving toilets;the four scenarios of the mixed and partially mixed collection have a low value of effluent and fertilizer and no agricultural value.The effluent should be managed as sewage.The SBR process can be adopted.Adding fillers and supplementing alkalinity enhance the treatment effect.When the ammonia nitrogen is less than or equal to 90 mg/L,the effluent can reach the standard stably.Finally,it clarified the selection schemes for the volume of the six scenarios of septic tanks.It proposed the“toilets+black wastewater collection+manure returning to the field”model based on resource utilization.The purpose of the"toilets+mixed collection of sewage+enhanced effluent treatment"mode based on environmental safety.Under separate collection scenarios A and D,the function of septic tanks is harmless and storage,which can support the utilization of manure resources.It is advisable to carry out related inspection and acceptance of toilet flushing volume and septic tank volume;under 4scenarios of mixed and partially mixed collection.The function of the septic tank is septic and sedimentation.The flushing volume of the toilet,collecting domestic sewage in the courtyard,the destination of the septic tank,and the sewage treatment system and the volume of the septic tank are subject to relevant inspection and acceptance.The septic tank optimization plan proposed in this paper can make up for the lack of a single septic tank volume verification scenario in the existing specifications,realize the guidance for the construction of septic tanks under the diverse rural water and sewage collection methods,and can effectively solve the problem of septic tanks.The overflow phenomenon of effluent improves the living environment in rural areas,enhances the happiness and satisfaction of farmers’lives,and helps rural revitalization.