I. Technical Name: Combined Anaerobic Digestion Technology for Sludge and Organic Matter such as Kitchen Waste II. Applicable Industries: Sewage Plant Sludge and Urban Organic Solid Waste Treatment and Disposal III. Scope of Application: Suitable for the anaerobic digestion biostabilization treatment of urban sludge and organic matter such as kitchen waste IV. Technical Content This technology is based on the poor buffering performance of single-stage digestion of kitchen waste, which leads to system acidification easily, while the sludge system has a high nitrogen content, high alkalinity, strong buffering capacity, but it is prone to produce free ammonia inhibition. By synergistically digesting sludge with organic matter such as kitchen waste, the problem of free ammonia/organic acids/salts inhibition produced by the digestion of each substrate alone can be alleviated. The addition of kitchen waste can significantly reduce the FAN concentration in the sludge system, effectively mitigating the issue of ammonia inhibition during the high solid content anaerobic digestion process of sludge. The high pH environment of sludge digestion can significantly reduce the hydrogen sulfide content in the biogas from the anaerobic digestion of kitchen waste. Dehydrated sludge is mixed with organic materials such as kitchen waste in a proportion (from the perspective of system stability, the range of VS ratio for sludge and kitchen waste is about 0.4:1 to 2.4:1). After mixing, the solids content ranges from 10% to 15%, and the digestion retention time is 20 days. Without increasing the pool capacity, this allows the sludge digestion facility to simultaneously accommodate an equivalent amount of kitchen waste treatment, significantly improving the operational efficiency of the project. V. Technical Demonstration and Promotion Application This technical achievement uses the Zhenjiang Sludge and Kitchen Waste Co-treatment Project with high solid content technology, which has a total processing scale of 260t/d, including 140t/d of kitchen waste (with a water content of 85%) and 120t/d of sludge (with a water content of 80%). The process flow adopted includes pre-treatment of kitchen waste + pre-treatment of sludge + high solid content/co-anaerobic digestion + deep dehydration and drying of biogas residue for land use + purification and upgrading of biogas to produce natural gas. The application effect shows that the methane yield of the digestion facility has increased by more than 1 time, and the expert group's acceptance opinion is 'a successful case of synergistic treatment and disposal of urban sludge and other organic waste in China.' Sixth, Energy Saving and Greenhouse Gas Emission Reduction Effect The application of this demonstration project has achieved stabilized treatment of 10 million tons of sewage sludge per year, reducing COD emissions by 30,000 tons per year, decreasing the discharge of secondary pollution from sludge, recovering biogas at 5 million cubic meters per year, reducing CO2 emissions by 10,000 tons per year, reducing greenhouse gas emissions, and simultaneously solving the long-standing problem of finding a solution for the disposal of kitchen waste. Seventh, Investment and Operation Cost Estimation This demonstration project fully utilizes existing pool capacity to treat urban organic matter such as kitchen waste, with investment costs and operation costs of about 160 million yuan and 160 yuan per ton, respectively, saving about 10% and 20% or more compared to similar technologies previously used. Eighth, The investment payback period for the current demonstration project is expected to be about 5-10 years. The biogas produced by the project, after purification and upgrading to natural gas, and the deep dehydration and biological drying of the sludge residue as a green substrate, has led to the establishment of a 'mobile forest' nursery base with an area exceeding 10,000 cubic meters using ventilated rooting pots in batches. The technical achievements have been well received by numerous domestic and international visiting units due to their technological advantages and favorable environmental and economic benefits. They align with the national direction of comprehensive treatment and disposal of sludge and sustainable development. The Zhenjiang demonstration project has been well received, indicating a promising future for its application and promotion.