Denggao Environmental Protection Technology Co., Ltd. is a technology-based enterprise specializing in the research, development, and application, and promotion of environmental technologies. It focuses on rural household toilet retrofitting and the harmless treatment and resource utilization of domestic sewage. The company possesses core proprietary technologies. 

    Through university-industry collaboration with institutions like Southeast University, the company has established a “Joint R&D Experimental Base” and a “Student Off-Campus Internship Base”. The provincial ecological and environmental research achievement transformation and promotion project it participated in—“Technology Transformation and Promotion of Low-Carbon, Quality-Based Separate Treatment Process for Rural Domestic Sewage in Water Network/Hilly Areas”—has passed the acceptance inspection by the Jiangsu Provincial Department of Ecology and Environment. Under the leadership of the Jiangsu Provincial Department of Ecology and Environment and Southeast University, it participated in drafting the Technical Guidelines for the Resource Utilization and Management of Rural Domestic Sewage in Jiangsu Province, and related achievements have been promoted and applied nationwide. The company has honored with awards, including China Invention and Entrepreneurship Award (First Prize), Silver Medal, Geneva International Invention Exhibition, and Science and Technology Innovation Award (First Prize).

    The company’s self-developed non-powered treatment process for rural domestic sewage addresses the drawbacks of conventional methods—“high energy consumption, high costs, and low adaptability”—through three core features: decentralized quality-based separate collection, enhanced degradation by bio-bacterial strains, and safe resource utilization. The process features include “zero energy consumption, sludge-free operation, low maintenance, sanitization, resource recovery, low costs, and multi-mode adaptability”. The process eliminates odors and mosquito breeding, making it suitable for villages with small populations and complex terrains. It overcomes the challenges of centralized sewage treatment facilities—“high pipe-network installation costs and difficult operation and maintenance”. The process has been widely applied in regions including Qinghai, Gansu, Shaanxi, Xinjiang, Inner Mongolia, Jiangsu, receiving consistent praise.

    The “enhanced microbial sewage treatment + resource utilization” process is adopted: blackwater sanitization tank (enhanced septic tank) + irrigation-standard pretreatment tank + discharge-standard advanced purification tank (optional) + resource utilization storage tank. The system operates without external power. Sanitization tank effluent complies with Sanitary Requirements for Fecal Sludge Sanitization (GB7959-2012). Irrigation-standard effluent meets Standards for Irrigation Water Quality (GB5084-2021) for vegetable plots and landscaping. The treated water enriches soil microbiota, improving structure and alleviating compaction. In ecologically sensitive areas, an optional discharge-standard advanced purification tank equipped with activated bio-filter media efficiently removes ammonia-N and phosphorus, meeting local discharge standards for rural sewage treatment. Compliant effluent may irrigate vegetable plots, or be discharged directly into water bodies. Active bacteria colonize river sediment, continuously decomposing organic matter to restore black-odorous water ecosystems.

    The bio-bacterial strains used have been certified by official testing institutions with CMA and CNAS qualifications, being non-toxic, harmless, and free of heavy metals. The strains are capable to self-propagate after initial inoculation, and tolerant to extreme temperatures. The activated bio-filter media for ammonia-N collection have been certified by test reports from the Ministry of Housing and Urban-Rural Development (MOHURD) and SGS.

The process advantages are as follows: 

Zero energy consumption: Operates entirely via gravity flow and natural microbial degradation, requiring no electrically driven equipment.

Sludge-free operation: Achieves fecal waste reduction via bio-bacterial strains, leaving no residue. 

Maintenance-free: Bio-bacterial strains self-propagate after initial inoculation, eliminating subsequent replenishment or part replacement. 

Harmless sanitization: Converts fecal waste into water and carbon dioxide while eliminating pathogens (coliforms, Salmonella, roundworm eggs). 

Resource recovery: The treated water can be used as organic liquid fertilizer and meets standards for irrigation water quality.

Low cost: Entire process requires no electricity or water, minimizing treatment expenses.

Multi-mode adaptability: Configurable for single-household or clustered treatment, tailored to local conditions.