Potable water trains · 0.5–50 m³/h · RO, mineralisation, UV/ozone
Drinking Water Treatment System — From Raw Water to the Tap
Quick answer
A drinking water treatment system turns municipal, borehole or surface water into potable water by combining pretreatment, reverse osmosis, remineralisation, pH correction, hygienic storage and a final UV or ozone barrier. The train is selected from the water analysis and the local drinking-water standard, not from a fixed catalogue; every finished system is pressure-tested before shipment.
- Treatment capacity
- 0.5–50 m³/h Treatment capacity
- RO permeate conductivity
- ≤10 µS/cm RO permeate conductivity
- Typical UV dose
- 30–40 mJ/cm² Typical UV dose
- Countries supplied
- 100+ Countries supplied
01
What does a drinking water treatment system include?
A drinking water treatment system is a train of unit operations, not one filter. Pretreatment removes turbidity, chlorine, organics, iron and hardness; reverse osmosis removes dissolved salts; post-treatment rebuilds alkalinity and pH; hygienic storage holds the water; and a final UV or ozone barrier protects the point of use.
The train is sized from the water analysis and peak hourly demand, not daily volume alone. A hotel that fills a tank each morning and a bottling line that draws water continuously need different hydraulic designs.
- 01
Pretreatment
Multimedia filtration, activated carbon, softener and 5 µm cartridge.
- 02
Reverse osmosis
0.5–50 m³/h, 50–75% recovery, permeate ≤10 µS/cm from feed ≤300 µS/cm.
- 03
Post-treatment
Remineralisation or blending, plus pH and alkalinity correction.
- 04
Storage
304 or 316L stainless tank with conical bottom, filtered vent and recirculation.
- 05
Final barrier
UV at 30–40 mJ/cm² or ozone at 0.2–0.5 mg/L, after storage.
02
What is a drinking water filtration system?
A drinking water filtration system removes the contaminants that make water cloudy, chlorinated, coloured or metallic: suspended solids, chlorine, taste and odour compounds, iron, manganese and some organics. It usually combines multimedia or cartridge filtration with activated carbon, and it may include softening when hardness is the issue.
It is not automatically a complete potable-water system. Filtration alone does not remove nitrate, sodium, TDS or viruses at the same reliability as RO and a final disinfection barrier. If the source is microbiologically uncertain or the TDS is high, the specification needs RO, disinfection, hygienic storage and finished-water testing — not only a filter housing.
- Typical scope: multimedia, carbon, cartridge, optional softener
- Good for: turbidity, chlorine, taste, colour, iron and manganese
- Not sufficient for: TDS, nitrate, sodium, microbiological risk without disinfection
03
What is an RO drinking water system?
An RO drinking water system uses reverse osmosis as the core desalination step, then remineralises the permeate, adjusts pH, stores it hygienically and protects it with UV or ozone. It removes 95–99% of dissolved salts, nitrate, sulphate, sodium and many heavy metals, which carbon and cartridge filtration cannot do.
The design must cover pretreatment, recovery and concentrate disposal. RO permeate is low in minerals and aggressive to metal and concrete, so blending or mineral dosing is part of the system, not an optional extra. For a commercial building, the RO is usually sized on peak drinking demand with storage, not on the whole-building water demand.
- Removes: TDS, nitrate, sulphate, sodium, many heavy metals
- Needs: pretreatment, remineralisation, disinfection and storage
- Plan: recovery 50–75% and a legal concentrate disposal route
04
What is a potable water treatment system?
A potable water treatment system covers the whole path from source to tap: intake or supply, treatment, storage, distribution and monitoring against the local drinking-water standard. The term is broader than a filter or an RO skid because it includes the hygiene of the tank, the loop and the point of use, and it assumes the finished water is tested, not only the equipment specified.
For a commercial building, the same functions are delivered in a smaller package: pretreatment, RO where needed, disinfection, storage and a recirculating loop. The local standard decides the limits and the testing frequency; the equipment supplier should state which limits the system is designed to meet and which tests are performed at the factory.
- Scope: source, treatment, storage, distribution, monitoring
- Standard: local potable-water limits, not a catalogue claim
- Evidence: finished-water test, tank and loop sanitation record
05
Which water quality parameters decide the treatment train?
Design starts with a laboratory analysis of the raw water, sampled at the source and repeated in wet and dry seasons where the source varies. Five parameters usually decide the architecture: TDS, hardness, turbidity, free chlorine and bacterial count; iron, manganese and pH refine it.
Targets below are typical potable-water references. Binding values are those in the local drinking-water standard, and the finished water must be tested against them.
| Parameter | Typical concern | Typical target | Treatment step |
|---|---|---|---|
| TDS | Above 1,000 mg/L, taste becomes noticeable | 150–500 mg/L | RO or blending |
| Hardness | Above 300 mg/L as CaCO₃ causes scale | 80–150 mg/L as CaCO₃ | Softener, or RO plus blending |
| Turbidity | Above 1 NTU shields microorganisms from UV | Below 1 NTU before UV | Multimedia filtration, UF, 5 µm cartridge |
| Free chlorine | Above 0.1 mg/L attacks polyamide membranes | Below 0.1 mg/L at the membrane | Activated carbon or bisulphite dosing |
| Bacterial count | Positive counts or E. coli indicate contamination | No E. coli or coliforms per local standard | UV, ozone or chlorination; hygienic storage |
| Iron and manganese | Above 0.3 mg/L Fe or 0.05 mg/L Mn stains tanks | Below 0.3 mg/L Fe and 0.05 mg/L Mn | Oxidation followed by filtration |
| Nitrate | Above 10 mg/L as N (about 45 mg/L as NO₃) | Below the local limit; commonly 10 mg/L as N | RO, ion exchange or blending |
| Arsenic | Above 0.01 mg/L or the local limit | Below 0.01 mg/L or the local limit | RO, adsorption or coagulation |
Typical references only. Confirm every limit against the local drinking-water standard and test the finished water.
06
How is RO permeate remineralised and pH-corrected?
RO removes 95–99% of dissolved salts, including the calcium, magnesium and bicarbonate that provide alkalinity and buffering. Permeate is therefore low in TDS, often below 30 mg/L, with little alkalinity and a negative Langelier Saturation Index. Untreated, it corrodes metal and concrete and tastes flat.
Three methods are common. Blending sends a controlled fraction of pretreated raw water around the RO; it is simple but only works when the raw water is potable. Mineral dosing adds calcium chloride, magnesium sulphate and sodium bicarbonate. Calcite beds dissolve calcium carbonate, and CO₂ dosing before the bed accelerates it.
Typical setpoints are pH 7.0–8.5, alkalinity 50–100 mg/L as CaCO₃ and LSI between -0.2 and +0.2. Exact values follow the local standard and downstream pipe material.
| Goal | Method | Typical setpoint | Watch out for |
|---|---|---|---|
| pH stability | Sodium hydroxide or carbonate dosing | pH 7.0–8.5 | Overdosing raises sodium |
| Alkalinity | Sodium bicarbonate, or CO₂ with calcite | 50–100 mg/L as CaCO₃ | CO₂ stripping raises pH |
| Mineral content | Calcium chloride and magnesium sulphate, or blending | TDS 150–400 mg/L | Keep chloride and sulphate balanced |
| Corrosion control | LSI adjustment and material selection | LSI -0.2 to +0.2 | Confirm with a coupon test |
Typical ranges for municipal-style permeate; adjust after jar testing.
07
Why does storage and distribution hygiene matter more than the RO?
RO permeate has no chlorine residual, so any microorganism entering the tank or pipework can settle and form biofilm. A tank vented to a dusty room, drained through a dead leg or held at 30 °C is a better incubator than a raw-water line. Most post-treatment contamination appears after the membrane.
Use a conical or sloped bottom, a sealed overflow with an insect screen, a 0.2 µm hydrophobic vent filter, a spray ball and no dead legs longer than three pipe diameters. Keep storage to one day or less.
- Recirculate through UV, or hold 0.2–0.5 mg/L ozone and monitor ORP.
- Clean and disinfect tanks every 3–12 months and after maintenance entry.
- Test heterotrophic plate count and coliforms at the tap, not only at the RO outlet.
08
UV or ozone at the final barrier — which should you choose?
Both are accepted final barriers, and they solve different problems. UV at 254 nm delivers 30–40 mJ/cm² and inactivates bacteria, viruses and protozoan cysts without adding anything to the water. It leaves no residual. Ozone is a dissolved oxidant: it also oxidises iron, manganese, colour and taste compounds and leaves a short-lived residual in the tank.
Choose UV when the water is clear and the risk is microbiological at the point of use. Choose ozone when the water needs oxidation or the tank and loop need protection. Some plants use ozone for tank recirculation and UV at the tap.
| Criterion | UV at 254 nm | Ozone |
|---|---|---|
| Typical dose | 30–40 mJ/cm² | 1–3 mg/L with 5–15 min contact |
| Residual | None | Short-lived; decays in minutes |
| Clarity needed | Below 1 NTU; 5 µm prefilter | Contacting and off-gas removal |
| Colour and taste | No effect | Oxidises colour and taste compounds |
| Iron and manganese | No effect | Oxidises, then filtration removes |
| By-products | None at 254 nm | Bromate possible with bromide present |
Typical values. Final selection depends on the raw water, the local standard and the validation required.
09
What certifications apply, and what must be tested locally?
HydroWorks manufactures under ISO 9001 and holds CE certification for the equipment it exports; the company is a national high-tech enterprise and holds several water-treatment patents. These cover quality management and product safety, not drinking-water approval.
Drinking-water compliance must be demonstrated by testing the finished water against the local standard. We do not claim a drinking-water certification or sanitary permit for these systems; any material approval or local test report must be obtained for the destination market.
Certification scope is stated per model. Ask for the certificate covering the exact configuration you order.
10
What water analysis and site data are needed before design?
A quotation is only as good as the analysis behind it. Sample at the source, not downstream of an existing softener, and state whether the source is municipal, borehole, river, lake or tanker water.
- Lab: TDS, conductivity, pH, alkalinity, hardness, calcium, magnesium, sodium, chloride, sulphate, nitrate, iron, manganese, arsenic, silica, COD, turbidity and bacterial count.
- Flow: peak hour, daily volume, operating hours and planned expansion.
- Site: power, drain, room size, ambient temperature, storage volume, pipe material and discharge rules.
Specifications
Delivery and service — typical ranges
| Item | Typical range |
|---|---|
| Standard skid lead time | 15–30 days after drawing approval |
| Containerized / turnkey lead time | 30–60 days after drawing approval |
| Warranty | 12–18 months from shipment |
| Factory testing | Hydrostatic pressure test and trial run with water before packing |
| Documentation | General arrangement drawing, P&ID, test record, O&M manual and spare-parts list |
| Packaging | Seaworthy plywood crate, or container for containerized plants |
| Installation support | Remote guidance as standard; on-site engineer available on request |
| Operator training | 1–2 days at commissioning, covering operation, CIP and consumables |
| Spare parts | Recommended two-year list quoted separately with the equipment |
| Payment terms | Typically 30% deposit and 70% before shipment; confirmed in the quotation |
| Minimum order | 1 unit |
| Loading port | Guangzhou or Shenzhen, China |
| Power supply | 220/380/415/440 V, 50/60 Hz; confirmed on order |
| Ambient temperature | 5–40 °C |
| Enclosure protection | IP54 for indoor skids; higher IP available on request |
| Certification | CE and ISO 9001; model-specific test reports on request |
Typical industry ranges for planning. Final scope, commercial terms and lead time are confirmed in the quotation.
FAQ
Frequently asked questions
Questions buyers actually ask during sizing and quotation. Answers match the specifications above.
01 How much does a drinking water treatment system cost?
02 Can I drink RO water directly?
03 Do I need UV if I already use ozone?
04 What TDS should drinking water have?
05 Can the system treat borehole water with iron and manganese?
06 How much water does the RO stage reject?
07 How often are cartridges, membranes and UV lamps replaced?
08 Is the equipment certified for drinking water?
Next step
Send your water analysis, get a factory quotation
Tell us the source water, TDS, hardness, iron and daily demand. Factory engineers reply with a flow rate, process train and budget range within one working day.