pH Neutralization, Equalization and Physical-Chemical Treatment
Equalization: usually the first thing worth building
Industrial discharges are batch or shift-based. Flow, pH, temperature and pollutant concentration
all swing widely through a day. Chemical systems only work within a design range and slug loads
defeat them, so the first unit that earns its keep is normally an equalization basin:
- It evens out swings so downstream pH control, precipitation and clarification see a steady
influent.
- It provides holding volume, so an off-specification batch can be held back and dealt with
instead of discharged.
- It is the practical answer to the "no feasible alternative" test that governs bypass.
An equalization basin must be mixed. Unmixed, solids settle out and accumulate - reducing the
working volume and eventually going septic and releasing odour and sulfide - a