What is a common effect of clarifier short-circuiting?

• A. Increased efficiency
• B. Reduced efficiency
• C. No change
• D. Higher solids removal

Answer: (B)

Short-circuiting happens when some of the flow takes shortcuts through the clarifier and exits before particles have a chance to settle. That cuts down the effective residence time for most of the water, so solids don’t have enough time to settle out. The result is poorer solids removal and therefore a drop in clarifier performance (reduced efficiency). You may also see more suspended solids in the effluent as a consequence. The other options would require more, not less, settling time or no change, which isn’t what short-circuiting causes.