3.世界各國以封城方式防堵新冠肺炎(Covid-19)的擴散,很多大企業、學校也以遠距工作或遠距教學的方式運行。試說明這樣的措施對辦公大樓或學校建物內自來水水質可能的影響。(10分)

7. To improve the nitrogen removal eficiency, an anoxic and aerobic (AO) process is proposed in a secondary municipal wastewater treatment plant. Please draw a schematic diagram and describe all the process, role of microorganisms, and mechanisms for nitrogen removal.(10分)