Industrial Wastewater
Metals precipitation, silica and hardness reduction, flue gas desulphurisation effluent, mining and quarry water, and process water loops — where the water is aggressive and the space is a corner of an operating plant.
Harder water, tighter sites, shorter outages
Industrial effluent treatment differs from municipal work in three ways that matter to equipment selection: the chemistry is often more aggressive, the available space is whatever the plant can spare, and the installation has to fit into a shutdown window measured in days.
Compact high-rate units answer all three. They are small enough to site inside an existing building or on a spare hardstanding, they are supplied pre-assembled for smaller duties, and their reactors are sized in minutes of residence time rather than hours — which keeps the equipment small even at high flow.
Metals precipitation
Hydroxide or sulphide precipitation followed by high-rate clarification removes dissolved metals to low residual concentrations in a fraction of the space a conventional clarifier would need. Where the metal is worth recovering, the high sludge concentration from integrated thickening — 2–4 % dry solids — makes downstream recovery and dewatering considerably more economical.
Silica and hardness
Silica is removed by co-precipitation with magnesium or aluminium species at elevated pH; hardness by lime softening. Both generate large volumes of dense precipitate. High-rate clarification carries the solids loading and thickens the sludge in the same structure, which is why it is the usual platform for boiler feed and cooling water pretreatment.
Flue gas desulphurisation effluent
FGD purge is high in dissolved solids, chlorides, gypsum fines and heavy metals, and is corrosive. The process itself is a straightforward precipitation and clarification duty; the engineering is in materials selection. We specify duplex or super-duplex stainless, lined carbon steel or FRP according to the chloride level and temperature, and state the assumptions in the offer.
Mining, quarry and aggregate water
Washwater from aggregate and mineral processing carries very high suspended solids and needs clarifying fast so the water can be returned to the wash plant. Ballasted flocculation handles the peak loading and the intermittent operating pattern; the compact configuration is often the right one where the plant is temporary or relocatable.
Process water and reuse loops
Cooling tower blowdown, boiler feed pretreatment and closed-loop process water reuse are all standard duties. Where the clarified water feeds membranes, magnetite ballasting is usually specified: the low residual turbidity and silt density index it delivers extend membrane life and cut clean-in-place frequency.
| Design parameter | Typical range |
|---|---|
| Rise rate — process water | 60–200 m/h ballasted |
| Rise rate — precipitation duty | 20–40 m/h |
| Influent suspended solids handled | up to several thousand mg/L |
| Metals residual after precipitation | typically < 0.1–1 mg/L, metal dependent |
| Silica reduction | to 5–20 mg/L with co-precipitation |
| Sludge concentration | 2–4 % DS with KWS-HRC |
| Materials — low chloride | Coated carbon steel or 304/316 stainless |
| Materials — high chloride / FGD | Duplex, super-duplex, lined steel or FRP |
| Packaged flow range | up to ~2,500 m³/h on skid or containerised |
| Typical installation window | days for packaged units; weeks for site-built |
Industrial duties vary widely. Treatability testing on an actual effluent sample is strongly recommended before a design basis is fixed.
Industrial effluents rarely behave the way a spot analysis suggests, particularly where several process streams combine. For anything unusual we would rather run jar tests on a real sample — and where the stream varies through a production cycle, on several taken at different times.
Treating an industrial effluent?
Tell us the stream, its variability and where the treated water has to go. We will say what is straightforward, what needs testing, and what we would not attempt.