Which of the following describes a step-feed influent scheme?

• A. Splits the influent into multiple treatment trains or tanks
• B. Treats influent sequentially in one tank
• C. Redirects flow to the sludge line
• D. Increases DO

Answer: (A)

Step-feed inflow means splitting the incoming wastewater into several treatment trains or tanks rather than sending it all into one place. This staged feeding helps spread the load, reducing shock to any single tank and giving you more uniform oxygen demand and treatment performance across the system. By distributing flow, you can better control mixing, retention times, and the biological processes involved, leading to more stable nitrification/denitrification and better overall effluent quality. The other options don’t describe distributing the influent load across multiple tanks or trains, which is what step-feed is all about.