Case study 06 / 12 · Division I
Division I · Case Study 06
Metal Finishing
Phys–Chem + Ion Exchange + ZLD
Surface-treatment and plating rinse waters carry toxic heavy metals, cyanide, fluoride and acids/alkalis. KEMISTA segregates streams, detoxifies chrome and cyanide, precipitates metals as hydroxides and polishes by ion exchange.
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Heavy metals
80%
Water recovery
−60%
Sludge volume
Selected treatment train
Plating / rinse
→
Segregation
→
Cr⁶⁺ / CN destruct
→
Hydroxide ppt
→
Lamella + filter
→
Ion exchange
→
Reuse
Indicative influent characteristics
pH (segregated)
–
1–13
Cr(VI)
mg/L
5–100
Ni
mg/L
10–200
Zn
mg/L
10–300
Cyanide
mg/L
1–50
Fluoride
mg/L
10–200
Contaminant removal efficiency
removal (%)
99.9%
Cr(VI)
99%
Ni
98%
Zn
99.5%
CN⁻
Why this configuration
Stream segregation enables selective Cr(VI) reduction and cyanide destruction.
Hydroxide precipitation + lamella clarification removes mixed metals reliably.
Ion-exchange polishing meets stringent discharge limits and enables reuse.
ZLD option evaporates concentrated regenerant for true zero discharge.
Your sector not listed, or a stream that defies the categories?
KEMISTA characterises the stream and engineers a bespoke train — that is what bench and pilot testing are for.