The upper part of the UASB reactor is equipped with a three-phase separator consisting of gas, solid, and liquid. The lower part consists of a sludge suspension layer and a sludge bed area. Wastewater is uniformly pumped into the sludge bed area from the bottom of the reactor and fully contacts and reacts with anaerobic sludge. Organic matter is decomposed into biogas by anaerobic microorganisms. Liquid, gas, and solid form a mixed liquid flow that rises to the three-phase separator, effectively separating the three and converting over 80% of organic matter into biogas, completing the wastewater treatment process.

应用特点：高COD负荷（5－10kgCODcr/m3/d）
可产生高沉降性能的颗粒污泥，可以产生能源（沼气）
运行费用低，高可靠性
应用范围：
高浓度废水，如酒精、糖蜜、柠檬酸等废水
中浓度废水，如啤酒、屠宰、软饮料等废水
低浓度废水，如生活污水等废水

注： 处理能力中分子为中温条件（35°C左右），分母为常温条件（20－25°C）；反应器可为正方形、长方形或圆形，方形为钢筋混凝土结构，圆形为钢结构钢筋混凝土结构；反应器的具体尺寸需要根据进水的水质特征确定。