Water Treatment Plant

Raw water clarified with coagulant, then filtered on sand/multi-media.

Raw water is dosed with coagulant (alum/PAC) and settled in a clariflocculator or tube settler, then filtered through a multi-grade/pressure sand filter at 10–15 m/h. Target outlet turbidity is <1 NTU and SDI₁₅ <5 — anything worse will foul RO membranes within weeks.

Activated carbon removes chlorine and organics.

The activated carbon filter adsorbs free chlorine, chloramine, organics, colour and odour. Removing chlorine is mandatory ahead of polyamide RO membranes and ion-exchange resin, both of which are destroyed by oxidants; where carbon cannot be trusted, SMBS is dosed and ORP is monitored instead.

Softener exchanges Ca²⁺/Mg²⁺ for Na⁺.

The softener's strong acid cation resin in sodium form swaps Ca²⁺ and Mg²⁺ for Na⁺, dropping hardness below 5 ppm as CaCO₃. When exhausted it is regenerated with 8–10 % brine (100–150 g NaCl per litre of resin) through backwash → brine draw → slow rinse → fast rinse, either on a timer or, better, on a throughput meter.

Reverse osmosis rejects dissolved salts (95–99%).

RO pushes water through semi-permeable spiral-wound membranes at 10–15 bar. Salts, silica and organics stay behind in the reject; permeate carries 1–3 % of the feed TDS. Antiscalant plus pH control prevent CaCO₃, CaSO₄ and silica scaling; recovery is held at 70–80 % with part of the reject recirculated. Normalise permeate flow, ΔP and salt passage daily — a 10–15 % change is the CIP trigger.

Mixed-bed / EDI polishes to boiler / ultrapure quality.

Final polishing removes the last traces of ions: a mixed bed of cation and anion resin (regenerated with HCl and NaOH) or an EDI stack that uses an electric field and membranes to regenerate continuously with no chemicals. Output reaches <0.1 µS/cm and >16 MΩ·cm for high-pressure boiler feed, power-plant or pharma use.