What is a Reverse Osmosis (RO) Plant?
A Reverse Osmosis (RO) plant purifies water by forcing it under high pressure through a semi-permeable membrane, removing 95–99% of dissolved salts, heavy metals, bacteria, and organic compounds. Industrial RO plants are used for boiler feed water, pharma-grade water, food processing, drinking water, and as post-treatment for STP/ETP systems. Cleantech Water manufactures skid-mounted RO systems from 500 LPH to 200 m³/hr for industries across Gujarat and pan-India.
In Gujarat’s industrial belt — from Ankleshwar’s chemical cluster to Surat’s textile zone to Rajkot’s engineering industry — the common thread in water treatment conversations is TDS. Groundwater in most of these locations tests between 800 and 3,000 mg/L dissolved solids, sometimes higher near industrial discharge zones. Municipal supply in Ahmedabad runs 300–600 mg/L. Neither is suitable for boiler feed water (which needs below 5 mg/L hardness by IBR standards), pharmaceutical process water (which needs conductivity below 1.3 µS/cm by IP standards), or sensitive food and beverage applications where taste, colour, and microbial quality are directly tied to water purity.150+
Installations Completed
13+
Years Manufacturing
500 LPH
to 200 m³/hr
95–99%
TDS Removal
How Does an Industrial RO Plant Work?
The operating principle of reverse osmosis is pressure-driven membrane separation. Feed water is pressurised (typically 8–20 bar for brackish water, 55–70 bar for seawater) and forced across a semi-permeable polyamide membrane with pore sizes of approximately 0.0001 microns — small enough to reject dissolved ions, bacteria, viruses, and organic molecules while allowing water molecules to pass through.
The output splits into two streams: permeate (purified water, 75–85% of feed volume in most industrial designs) and concentrate/reject (remaining 15–25%, containing the rejected dissolved solids). The reject stream is either discharged to drain, returned to feed water, or — in ZLD systems — sent to an evaporator for further concentration and salt recovery.
RO Plant Process Flow — Stage by Stage
| Stage | Equipment | Purpose |
|---|---|---|
| 1. Raw water storage | Feed water tank (FRP/HDPE) | Buffer storage; ensures consistent feed flow to pre-treatment |
| 2. Coagulation/dosing | Dosing pump + chemical tank | Alum or FeCl₃ dosing for turbidity coagulation; antiscalant dosing to prevent membrane scaling |
| 3. Multi-media / pressure sand filter | Pressure sand filter | Removes suspended solids, turbidity, iron — SDI reduction to protect membranes |
| 4. Activated carbon filter | Activated carbon filter | Removes chlorine, chloramines, organics — critical because chlorine destroys polyamide RO membranes |
| 5. Micron cartridge filter | 5-micron cartridge housing | Final particle guard before high-pressure pump — protects pump and membrane from particulates |
| 6. High-pressure pump | Stainless steel centrifugal/multistage pump | Pressurises feed to 8–20 bar (brackish/groundwater); 55–70 bar for seawater desalination where applicable — energy-intensive stage |
| 7. RO membrane array | TFC polyamide spiral-wound membranes in FRP pressure vessels | Core separation stage — removes 95–99% TDS, bacteria, viruses, organics |
| 8. Post-treatment | pH correction, remineralisation, UV, chlorination | Application-specific: drinking water needs pH adjustment; pharma needs conductivity polishing |
| 9. Permeate storage + distribution | Product water tank + distribution pump | Treated water storage and pressure for distribution to end-use point |
Why pre-treatment matters more than the membrane: Most industrial RO membrane failures in India are caused by inadequate pre-treatment — specifically, chlorinated municipal water reaching polyamide membranes without activated carbon dechlorination, and high-turbidity borewell water bypassing proper sand filtration. A common failure pattern in the industry — and one we have encountered when troubleshooting poorly performing plants — is a ₹5 lakh RO membrane array damaged within 6 months because the pre-treatment design skipped the activated carbon stage to reduce capital cost. The right sequence — PSF → ACF → cartridge filter → RO — is non-negotiable.
Cleantech Water RO Plant — Technical Specifications
| Capacity Range | 500 LPH to 200 m³/hr (200,000 LPH). Skid-mounted packaged systems up to 50 m³/hr; larger capacity in modular multi-skid configuration |
| Membrane Type | TFC (Thin Film Composite) polyamide spiral-wound — leading brands available: Dow FilmTec, Hydranautics, Toray, Koch. Membrane selection based on feed water TDS and temperature |
| TDS Removal | 95–99% salt rejection. Feed TDS up to 10,000 mg/L (brackish); above 10,000 mg/L requires seawater membranes or two-pass RO design |
| Water Recovery | 70–85% permeate recovery (15–30% reject). Recovery rate varies with feed TDS — higher TDS reduces achievable recovery without scaling risk |
| Operating Pressure | 8–20 bar for brackish/groundwater (most industrial applications). 55–70 bar for seawater desalination where applicable. Booster pump pressure set per membrane manufacturer’s operating envelope |
| Vessel MOC | FRP pressure vessels (standard), SS 304 (food-grade), SS 316 (pharma/corrosive feeds). Skid frame: MS epoxy-coated or SS 304 |
| Instrumentation | Feed/permeate/concentrate pressure gauges, flow meters, conductivity/TDS meters, high-pressure cut-off switch, low-pressure switch, PLC control panel (on automatic systems) |
| Installation Type | Skid-mounted (plug-and-play) — indoor or outdoor weather-proof canopy. Civil foundation required for larger systems |
| Membrane Life | 3–7 years with proper pre-treatment and CIP (Clean-in-Place) maintenance. Life significantly reduced by chlorine exposure or fouling from inadequate pre-filtration |
RO Plant Capacity Guide & Cost — 2026 India
RO plant sizing is driven by your daily purified water requirement and peak demand. Always size for peak flow, not average — an RO plant that cannot keep up during shift production peaks creates process interruptions that cost more than the capital saved by undersizing. Here are realistic 2026 price ranges for Cleantech Water’s industrial RO systems, turnkey (supply + installation + commissioning):
| Capacity | Suitable Application | Approx. Cost (Turnkey) | MOC |
|---|---|---|---|
| 500 LPH – 1,000 LPH | Small clinic, school, guesthouse, lab | ₹1.5–₹4 lakh | FRP/MSRL |
| 2,000–5,000 LPH | Hospital, hotel, housing society drinking water | ₹4–₹12 lakh | FRP / SS 304 |
| 10,000–20,000 LPH | Small industry, boiler feed, food processing | ₹12–₹30 lakh | SS 304 / SS 316 |
| 50,000 LPH (50 m³/hr) | Large industry, pharma plant, township | ₹35–₹70 lakh | SS 304 / SS 316 |
| 100–200 m³/hr | Large industrial, ZLD pre-treatment, desalination | ₹80 lakh–₹2 crore+ | SS 316 / custom |
*Prices include pre-treatment (PSF + ACF + cartridge filter), high-pressure pump, membrane array, instrumentation, skid fabrication, and commissioning. Excludes 18% GST and civil work. Feed water with TDS above 5,000 mg/L or high fouling potential (textile effluent, high-COD feed) adds 20–40%. Contact Cleantech Water for a site-specific quotation.
RO vs UF vs DM Plant — Which Technology Is Right for Your Application?
RO is not always the right answer. Selecting the wrong technology for your feed water quality and end-use requirement leads to either over-treatment (excess capital and operating cost) or under-treatment (water quality that fails your process). Here is how the choice plays out across common Indian industrial applications:
| Technology | What It Removes | TDS Reduction | Best Application |
|---|---|---|---|
| UF (Ultrafiltration) | Bacteria, viruses, colloids, TSS — NOT dissolved salts | None | Drinking water polishing, RO pre-treatment, STP effluent polishing |
| RO (Reverse Osmosis) | 95–99% dissolved salts, bacteria, viruses, organics | 95–99% | High-TDS feed water, boiler makeup, pharma, food processing, ZLD pre-treatment |
| DM Plant (Ion Exchange) | All dissolved ions — conductivity approaches 0 | >99.9% | High-pressure boilers (IBR), semiconductor, electronics, pharma purified water |
Most common combination for Gujarat industries: RO system as primary treatment, followed by a mixed-bed DM plant as a polishing stage for high-pressure boilers or pharma applications where conductivity must approach zero.
Industries and Applications — Where Cleantech Water Has Installed RO Plants
🏭 Boiler Feed Water
IBR-compliant feed water below 5 mg/L hardness. RO followed by DM polishing for high-pressure boilers in textile, food, pharma, and chemical plants across Gujarat
💊 Pharmaceutical & API
RO + EDI or mixed-bed DM for Purified Water (USP/IP Grade). Pharma clusters in Ankleshwar, Vadodara — stringent WHO/GMP-compliant water quality
🍼 Food & Beverage
FSSAI-compliant process water. RO for ingredients water in dairy, packaged food, beverages — removes pesticides, heavy metals, and organics that affect taste and safety
🧵 Textile Industry
Soft, low-TDS water for dyeing — hard water causes uneven dye uptake and colour fastness issues. RO eliminates scaling on dyeing machines and reduces chemical consumption
🏥 Hospitals & Dialysis
AAMI/ANSI grade water for haemodialysis. RO with bacterial monitoring — dialysis water quality directly impacts patient outcomes; no compromises on membrane selection or pre-treatment
♻️ ETP/STP Treated Water Reuse
RO as tertiary polishing stage after STP/ETP for ZLD compliance or process water reuse. Treated effluent after biological treatment becomes RO feed — reducing freshwater intake by 60–80%
⚙️ Cooling Tower Makeup
Low-TDS makeup water reduces cycles of concentration management burden, scale formation on heat exchangers, and chemical consumption in cooling water treatment programs
🏢 Commercial Buildings & Townships
Centralized RO for potable water in IT parks, residential townships, hotels — eliminates individual point-of-use purifiers and ensures consistent water quality building-wide
Get a Custom RO Plant Quote for Your Industry
Cleantech Water designs RO plants around your actual feed water quality and end-use requirement — not a catalogue selection. Free feed water analysis and system recommendation across Gujarat and pan-India.
Frequently Asked Questions — Reverse Osmosis Plant
What is an RO plant and how does it work?
An RO plant (Reverse Osmosis plant) purifies water by forcing it under high pressure (8–20 bar for brackish water) through a semi-permeable TFC polyamide membrane with 0.0001-micron pores. The membrane achieves salt rejection of 95–99%, blocking dissolved salts, heavy metals, bacteria, viruses, and organics while allowing water molecules to pass through as purified permeate. The rejected dissolved solids exit as a concentrate stream. Pre-treatment (pressure sand filter + activated carbon filter + cartridge filter) is essential before the membrane stage to prevent fouling and extend membrane life.
What is the cost of an RO plant in India?
Industrial RO plant cost in India ranges from ₹1.5 lakh for a 500 LPH system to ₹2 crore+ for a 200 m³/hr plant. A 10,000 LPH industrial RO for boiler feed or food processing costs ₹12–₹30 lakh installed. Monthly operating cost (electricity + membrane CIP chemicals + cartridge filters) runs ₹5,000–₹50,000 depending on capacity and feed water quality. Membrane replacement (every 3–7 years with proper maintenance) adds ₹3,000–₹15,000 per element depending on size — 4040 elements (small systems) cost ₹3,000–₹8,000 each; 8040 elements (larger industrial systems) cost ₹8,000–₹15,000 each. Contact Cleantech Water for a site-specific quotation based on your feed water analysis.
What are the main components of an RO plant?
The main components of an RO plant are: (1) Feed water tank for storage and flow buffering; (2) Dosing systems for antiscalant and coagulants; (3) Pressure sand filter for turbidity/iron removal; (4) Activated carbon filter for dechlorination; (5) Micron cartridge filter (5-micron) as final pre-filter; (6) High-pressure pump (stainless steel); (7) RO membrane elements in FRP pressure vessels; (8) Permeate tank; (9) Control panel with instrumentation (TDS meter, flow meters, pressure gauges); (10) CIP (Clean-in-Place) system for periodic membrane cleaning.
How much water does an RO plant waste?
A standard industrial RO plant achieves 70–85% water recovery — meaning 70–85 litres of purified water is produced per 100 litres of feed, with 15–30 litres exiting as concentrate/reject. Recovery rate depends on feed water TDS: low-TDS feeds (below 500 mg/L) can achieve 80–85% recovery; high-TDS feeds (above 3,000 mg/L) may be limited to 65–70% without scaling risk. In ZLD systems, the concentrate is sent to an evaporator for further water recovery, effectively eliminating liquid discharge.
How long do RO membranes last?
RO membranes last 3–7 years in industrial applications with proper pre-treatment and regular CIP (Clean-in-Place) maintenance. The primary causes of premature membrane failure in India are: (1) chlorine exposure — even trace free chlorine degrades polyamide membranes irreversibly; (2) inadequate pre-filtration allowing colloidal fouling; (3) scaling from calcium carbonate or silica when antiscalant dosing is inadequate or interrupted. An activated carbon filter and consistent antiscalant dosing are the two most cost-effective investments in membrane life extension.
Can an RO plant treat STP/ETP effluent for reuse?
Yes — RO is the standard tertiary treatment stage in industrial water reuse and ZLD systems. After biological treatment in an effluent treatment plant or sewage treatment plant, the treated effluent (with BOD/COD meeting CPCB norms) is fed to an RO system for TDS reduction and polishing. The RO permeate can then be reused as cooling tower makeup, toilet flushing, or even process water depending on quality requirements. This combination — biological treatment + RO — enables 60–80% freshwater reduction in water-intensive industries.
Do you offer AMC for RO plants?
Yes — Cleantech Water provides Annual Maintenance Contracts (AMC) for all installed RO plants. AMC coverage includes quarterly preventive maintenance visits, membrane performance testing, antiscalant dosing calibration, cartridge filter replacement, CIP chemical supply, and emergency call-out support. AMC cost for a 10,000 LPH industrial RO runs approximately ₹60,000–₹1,20,000 per year depending on scope. Regular AMC significantly extends membrane life and maintains consistent permeate quality.
Cleantech Water is a water treatment plant manufacturer in Ahmedabad, Gujarat, with 13+ years of industrial RO plant design, supply, and commissioning experience across Gujarat, Maharashtra, Rajasthan, Madhya Pradesh, Telangana, and Chhattisgarh. For RO plant enquiries — feed water analysis, capacity sizing, or AMC for an existing plant — contact us at +91-9558996411 or Info@cleantechwater.co.in. We assess your feed water quality before recommending a system, because every RO plant’s performance is ultimately determined by what goes into it, not just the membrane inside it.
Vipul Chavda — Co-Founder, Cleantech Water
Vipul has 13+ years of hands-on experience designing and commissioning industrial RO plants, DM plants, and complete water treatment systems for pharma, textile, food processing, and industrial clients across Gujarat and India. Cleantech Water has delivered 150+ installations for clients including GIFT City, Adani, TATA, Mother Dairy, L&T, and Arvind Group.