sewage sludge treatment

例句：

1. 1. The city's sewage treatment plant is responsible for removing pollutants from the city's wastewater.
   这个城市的污水处理厂负责从城市废水中去除污染物。
2. 2. The sewage treatment process involves several stages to ensure that harmful substances are removed from the wastewater.
   污水处理过程涉及多个阶段，以确保从废水中去除有害物质。
3. 3. The sewage treatment plant has been upgraded to handle larger volumes of wastewater and improvethe quality of the treated water.
   污水处理厂已经升级，以处理更大的废水量并提高处理过的水的水质。