🔍 Key Concepts

• Basic principle of separation by gravity for oil and water with different densities • Purpose of an inclined plate coalescer vs a polishing filter coalescer • How systems are usually arranged from bulk removal to fine/finishing treatment

💭 Think About

• Ask yourself: which process would logically remove the largest oil droplets and free oil first, using the simplest method? • Between an inclined plate coalescer and a polishing filter coalescer, which one sounds more like a final clean‑up/finishing stage? • Think about normal design of treatment systems: do we usually go from coarse to fine, or fine to coarse separation?

✅ Before You Answer

• Make sure the first stage is the simplest, most basic form of separation (no fine filtering). • Confirm that the last stage should be the one that gives the cleanest, most polished effluent, ready to meet discharge standards. • Check whether the inclined plate coalescer is typically used for intermediate separation (helping droplets join and rise) rather than as the final polishing step.