东南沿海地区典型餐厨垃圾处理工程设计及运行实例

Design and Operation Examples of Typical Food Waste Treatment Project in Southeast Coastal Area of China

餐厨垃圾具有有机质含量高、含水量大和易腐败变质等特点,容易造成环境污染,推进餐厨垃圾处理有助于实现废物的减量化、资源化和无害化。本研究中的东南沿海地区典型餐厨垃圾处理工程主要由预处理系统、厌氧发酵系统、沼气净化系统、污水处理系统、锅炉系统和除臭系统等工艺单元组成。该工程运行效果受餐厨垃圾收运质量、当地饮食特点(贝壳等重物质为平均水平的1.4倍等)以及餐厨垃圾收运量(平均为设计处理量的1/4)等因素影响较大,调试期间预处理系统卡堵严重,厌氧系统沼液中COD/氨氮浓度≈2(<5),污水系统为维持稳定运行需投加大量碳源,生物脱硫系统因硫负荷低于设计值的1/3而不适宜接种污泥;通过在运行过程中严控收运质量,添加预处理系统设备(额外砂石输送线路),调整沼气净化系统运行模式(调整为碱法脱硫)以及用预处理系统三相分离液作碳源按1∶5~1∶10调配污水进水量等方式,确保了各系统稳定达标运行,厌氧系统产气量和甲烷浓度平均为62 m^(3)/t(进厌氧罐物料)和60%。该工程的设计及运行经验期望能为其他同类型工程提供参考,有助于推动相关项目工程低成本达标稳定运行。

Food waste has the characteristics of high organic matter content,high waster content,and easy deterioration,which was easy to pollute the environment.The promotion of food waste treatment is conducive to the reduction,recycling and harmless of waste.In the study,the typical food waste treatment project in southeast coastal areas were mainly composed of food waste pretreatment system,anaerobic fermentation system,biogas purification system,sewage treatment system,boiler system and deodorization system.The operation effect of the project was influenced by the factors such as the quality of food waste collection,the characteristics of local diet(heavy matters was 1.4 times the average such as shell)and the volume of food waste collection and transportation(only have 1/4 design capacity on average).During the commissioning of the project,the pretreatment system was stuck seriously,the concentration of COD/ammonia nitrogen in biogas slurry of the anaerobic system was approximate to 2(<5),the sewage system needed to add a large number of carbon sources to maintain stable operation,and the sulfur load was less than 1/3 of the design led to the biological desulfurization system was not suitable for sludge inoculation.Through strictly controlling the quality of collection in the operation,adding additional equipment to the pretreatment system(gravel conveying line),adjusting the operation mode of biogas purification system(adjusted to alkali desulfurization)and using the three-phase separation liquid of the pretreatment system as the carbon source to allocate the sewage water inflow at the ratio of 1∶5~1∶10,etc,the stable and up-to-standard operation of the project could be ensured,the average gas production and methane concentration of the anaerobic system were 62 m^(3)/t(into the anaerobic tank material)and 60%.The design and operation experience of the project could provide reference for other similar projects,and contribute to promoting the stable operation of similar projects at low cost and up to standards.