"污水工程系统" can be translated into English as "sewage engineering system" or "wastewater engineering system".
"Sewage" specifically refers to waste matter carried off by sewers, which includes domestic and industrial wastewater.
"Wastewater" is a broader term that encompasses all types of water that has been used and may contain contaminants, including sewage.
Both translations are acceptable, and the choice between them may depend on the specific context or emphasis of the discussion. In engineering contexts, "sewage engineering system" might be more commonly used when referring specifically to the systems designed for the collection, treatment, and disposal of sewage. However, "wastewater engineering system" is also widely used and can be more inclusive, covering various types of wastewater beyond just sewage.