Effluent Treatment
Colour does not track COD. A plant can pass every oxygen-demand limit and still discharge visible dye.
— %
Inlet to outlet ADMI across the plant
ADMI is reported on a 1 cm path length at a stated pH; colour is pH-sensitive for many dye classes, so a reading taken before neutralisation is not comparable with one after it. The specific removal figure is a simple ratio and will fall as dose rises because colour removal saturates - it is a tracking metric, not a linear coefficient to extrapolate. Coagulant dose also generates sludge, which is a separate cost and is not included here. The ADMI to Pt-Co factor is site and shade specific and the two scales are not interchangeable; where a permit names one, measure that one rather than converting.
Effluent Colour ADMI Removal, Compliance Margin & Chemical Cost — free, with the formula and a worked example, at Textile School.