The Non-Powered Treatment Process for Rural Domestic Sewage

Denggao Environmental Protection Technology Co., Ltd. is a technology-based enterprise specializing in the research and application promotion of environmental protection technology for rural household toilet renovation, harmless treatment of domestic sewage, and resource utilization. It has core proprietary technology and is honored to serve as the supervisory unit of Nantong Environmental Protection Industry Association. The company has cooperated with universities such as Southeast University to establish a "Joint R&D Experimental Base" and a "Student Off campus Internship Base". Under the leadership of the Jiangsu Provincial Department of Ecology and Environment and Southeast University, the company participated in the preparation of the "Jiangsu Province Rural Domestic Sewage Resource Utilization and Control Technical Guidelines".

The company has been consistently dedicated to the R&D and innovation of non-powered treatment products and processes fo rural domestic sewage, and ha been honored with the following awards (partial list):

1.China  Invention and Entrepreneurship Award  (First  Prize)

2.Silver  Medal,  Geneva  International Invention Ex hibition

3.Science  and  Te chnology  Innovation Award (First    Prize)

                    Standard for Irrigation Water Reuse

Effluent Discharge Standards

  Our independently developed rural domestic sewage non powered treatment process has the advantages of efficient treatment, low-cost operation, zero chemical agent addition, and no secondary pollution. The treatment process has no odor and suppresses mosquito and insect breeding. In single household sewage treatment, each household is equipped with one harmless treatment tank, one oil and slag separation tank, and a deep purification tank (with separate discharge and irrigation standards). The specific treatment process is as follows:

  Install an oil and residue separation tank near the kitchen drainage outlet, which effectively intercepts food residue and oil through physical separation, and preliminarily purifies water quality.

  In the harmless treatment tank, a stable microbial system is formed by adding biological strains and specialized hanging spherical fillers. The bacterial strains attach and grow on the surface of the packing material, with strong resistance to hydraulic shock, which can avoid the loss of microbial communities, gradually decompose large organic molecules into small molecules, significantly reduce the COD value of sewage, and remove surfactants from water. Solid organic matter such as manure skin and toilet paper are simultaneously decomposed into carbon dioxide and water, achieving a reduction in manure and completely eliminating traditional cleaning operations. The treated water meets the hygiene requirements for harmless treatment of feces (GB7959-2012), with an Escherichia coli group of ≤ 10000/liter, a removal rate of roundworm eggs and Salmonella of ≥ 98%, a stable pH value in the range of 7-9, and produces organic liquid fertilizer that can be directly used for irrigating crops. When liquid fertilizer is not needed, the treated water is combined with kitchen treated water, laundry water, bath water, etc. and enters the deep purification pool.

  Biological bacteria, specialized spherical membrane packing, and deodorizing water purification filter material are added to the deep purification tank of irrigation standards. Through the composite effect of "bacteria+material", pollutants in sewage are deeply degraded to achieve irrigation standard effluent. The drainage overflow from the deep purification tank of the irrigation standard enters the clear water tank. The standard irrigation water in the clear water tank can be used to irrigate farmers' small vegetable gardens. If not needed, it can enter the surrounding soil through the permeable holes on the wall of the clear water tank. The microbial community in the water can synchronously improve the soil structure and alleviate the problem of compaction.

  For sensitive water areas, an additional deep purification tank with discharge standards is installed, equipped with biological filter media for ammonia nitrogen and phosphorus removal. With the synergistic effect of biological bacteria, the ammonia nitrogen removal rate is greater than 90% and the total phosphorus removal rate is greater than 85%. The water that meets the standards overflows into the clean water tank and can be used to irrigate farmers' small vegetable gardens. If not needed, it can be directly discharged into the water body. The active bacterial community in the water that meets the standards can colonize and reproduce in the riverbed, continuously decompose the organic matter in the sediment, and promote the ecological restoration of black and odorous water bodies.

  Our biological strains have the functions of self dormancy and self activation, maintaining activity at extreme temperatures ranging from -40 ℃ to 60 ℃. They have been double tested and certified by Ningbo Customs and China National Chemical Institute, and are non-toxic, harmless, and free of heavy metals. They are recognized in China and internationally.

  This process is free from cleaning, generates no sludge, is low-cost, multi-mode, non powered, maintenance free, harmless, and resourceful.

Bio-Bacterial Strains

The "DGHBJZ-001 Biological Strain" is an effective microbial community developed by our laboratory after years of independent research and development. It collects effective microorganisms from nature and uses advanced microbial genetic engineering cultivation technology. After repeated screening, it finally becomes a mixed culture of anaerobic and facultative beneficial microorganisms. Biological strains have the functions of self dormancy and self activation, and can ensure their efficacy and activity even in extreme temperatures of 60 degrees Celsius and 40 degrees Celsius. Biological strains can attach and grow on active biological filter media, effectively avoiding the loss of microbial strains caused by excessive water flushing load. This biological strain utilizes its own biological reactions to decompose organic pollutants, ultimately producing structurally stable, non-toxic, and harmless substances (such as carbon dioxide and water), avoiding secondary pollution. This biological strain has obtained testing reports from Ningbo Customs and China National Chemical Institute. The Escherichia coli group has been reduced to below 10000, and the removal rates of roundworm eggs and Salmonella can reach over 98%. The pH value is stable at 7-9. This biological strain is non-toxic, harmless, and does not contain heavy metals. It is recognized in China and internationally.

Bio-Filter Media Preparation

DGZJYJ-01A Active Biological Filter Material "serves as a carrier for biological bacteria, achieving further degradation of organic matter and ammonia nitrogen, with a removal rate of over 90% for ammonia nitrogen and over 85% for total phosphorus. Avoiding the use of pesticides and reducing operational costs has significant technical advantages, and has obtained testing reports from the Ministry of Construction and SGS.

1. Energy consumption and power demand

Non powered processing technology: relying entirely on gravity flow and natural microbial degradation, without the need for electrically driven equipment such as pump stations, aerators, etc. Biological strains remain active at extreme temperatures (-40 ℃ to 60 ℃) and have strong adaptability.

Pipeline collection: relying on centralized sewage treatment stations, high energy consumption such as pump stations and aeration tanks need to be built, and electricity costs account for 30% -50% of operating expenses, with high requirements for grid stability.

Advantages after comparison: Non powered technology significantly reduces energy dependence and is more suitable for rural use, especially in areas with weak power infrastructure.

2. Construction and operation costs

Non powered treatment process - construction: New harmless treatment tanks can be built, and farmers' existing septic tanks can be renovated to add small facilities such as oil separators and treatment tanks. There is no need for long-distance pipeline networks, and single/multiple households can be flexibly configured to reduce initial investment.

Operation and maintenance: No sludge is generated (organic matter decomposes into CO2 and water), no cleaning is required, no chemical agents are added, and maintenance costs approach zero.

Pipeline collection - construction: complex sewage pipeline network needs to be laid and centralized treatment stations need to be built, which incurs high construction costs.

Operation and maintenance: Regular cleaning of sludge, payment of electricity and chemical fees are required, resulting in high overall costs.

Advantages after comparison: The non powered process saves more than 90% of operation and maintenance costs, and there is no burden of subsequent processing.

3. Pollutant removal and resource utilization

Non powered treatment process - treatment effect: COD significantly reduced, ammonia nitrogen removal rate>90%, total phosphorus>85%, harmless treatment tank effluent meets the "Sanitary Requirements for Harmless Feces" (GB7959-2012), Escherichia coli group ≤ 10000/L, and organic liquid fertilizer can be directly used to irrigate crops. The irrigation standard effluent meets the "Irrigation Water Quality Standards for Farmland" (GB5084-2021), and can be used for irrigating small vegetable gardens and tree gardens. If the effluent meets the discharge standards of water pollutants for rural domestic sewage treatment equipment (DB32/3462), it can be directly discharged in compliance with the standards.

Resource utilization: producing organic liquid fertilizer rich in bacterial strains, which can improve soil structure and alleviate compaction problems; The active bacteria in the discharged water can decompose the sediment of rivers and canals, helping to restore black and odorous water bodies.

Pipeline collection: Although centralized pipeline collection for sewage treatment can meet the standard, the tail water is mostly directly discharged into the water body, lacking resource utilization, and chemical agents may damage the environmental ecology.

Advantage: The non powered treatment process can achieve a closed loop of "sewage fertilizer ecological restoration", reducing water resource waste and non-point source pollution.

4. Environmental friendliness and adaptability

Non powered processing technology: No odor or mosquito or fly breeding throughout the process, certified non-toxic and harmless biological strains, and no secondary pollution. Distributed processing is suitable for the dispersed characteristics of rural residential areas, without the need for large-scale land acquisition and with a short construction period.

Pipeline collection: The risk of pipeline leakage can lead to groundwater pollution, and treatment plants may produce odors and noise that disturb residents; Centralized processing requires high population density and insufficient coverage in remote rural areas.

Advantage: The non powered processing technology is more in line with the practical needs of rural ecological sensitivity and dispersed living.

5. Socio economic benefits

Non powered processing technology: Farmers can obtain liquid fertilizer for free, reducing planting costs; Reduce labor input and liberate rural labor. No professional technicians are required to operate, and villagers can independently maintain it.

Pipeline collection: Pipeline construction often involves disputes over land compensation, and the processing plant requires a professional operation team with low relevance to the interests of farmers.

Advantage: The non powered treatment process enhances farmers' participation and achieves a win-win situation for environmental governance and agricultural production.