陇西县城区污水处理厂改造工程设计及运行

Design and Operation of Retrofitting Project of Sewage Treatment Plant in Longxi County

陇西县城区污水处理厂出水水质达不到《城镇污水处理厂污染物排放标准》(GB18918—2002)的一级B标准,因此对二级处理工艺进行了改造,拆除了原有CASS池中的填料和部分墙体,并在原有好氧池基础上增加了选择池、厌氧池和缺氧池,将生物处理工艺改造成改良型卡鲁塞尔氧化沟工艺。通过两个多月的试运行,出水NH_3-N<15 mg/L、TN<20 mg/L、TP<1 mg/L、COD<60 mg/L、BOD_5<20 mg/L,实现了达标排放。

The secondary treatment process of the sewage treatment plant in Longxi County was modified, because the effluent quality did not meet the first level B criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （GB 18918- 2002）. In the retrofitting project, part of the wall and the filler in the CASS tank were removed, the selection tank, anaerobic tank and anoxic tank were added based on the original aerobic tank, and the biological treatment process was turned into an improved Carrousel oxidation ditch. After more than two months of trial operation, the con- centrations of NH3 -N, TN, TP, COD and BODs in the effluent were 〈 15 mg/L, 〈 20 mg/L, 〈 1 mg/L, 〈 60 mg/L and 〈 20 mg/L respectively, and the effluent quality met the discharge standards.