Two Stage Reverse Osmosis Bottle Drinking Water System

1. Full stainless steel.

2. Scientific design, reasonable pipe layout.

3. Compact construction, reasonable pipe laying.

4. User friendly -- full-automatic control with PLC & touch screen.

5. Online quality monitoring for output water.

6. System stops in case of water shortage or tank full.

7. Auto flushing for RO membrane to reduce the RO membrane pollution.

8. USA DOW reverse osmosis membrane, with a long service life for 3-5 years.

9. CNP SUS pump, durable and low running noise.

10. Self-developed pretreatment system, greatly protect the RO membrane.  

What is Reverse Osmosis?

Reverse Osmosis is a technology that is used to remove a large majority of contaminants from water by pushing the water under pressure through a semi-permeable membrane. To understand the purpose and process of Reverse Osmosis you must first understand the naturally occurring process of Osmosis.


Osmosis is a naturally occurring phenomenon and one of the most important processes in nature. It is a process where a weaker saline solution will tend to migrate to a strong saline solution. Examples of osmosis are when plant roots absorb water from the soil and our kidneys absorb water from our blood.

Reverse Osmosis

A semi-permeable membrane is a membrane that will allow some atoms or molecules to pass but not others. A simple example is a screen door. It allows air molecules to pass through but not pests or anything larger than the holes in the screen door.

Reverse Osmosis is the process of Osmosis in reverse. Whereas Osmosis occurs naturally without energy required, to reverse the process of osmosis you need to apply energy to the more saline solution. A reverse osmosis membrane is a semi-permeable membrane that allows the passage of water molecules but not the majority of dissolved salts, organics, bacteria and pyrogens. However, you need to ‘push‘ the water through the reverse osmosis membrane by applying pressure that is greater than the naturally occurring osmotic pressure in order to desalinate (demineralize or deionize) water in the process, allowing pure water through while holding back a majority of contaminants.

Two Stage RO Equipment Introduction

A complete 2 stage RO pure water equipment consists of pretreatment system, stage-1 RO system, PH regulating system, middle pure water storage system (optional for large equipment), stage-2 RO system, water storage tanks, and auto backwash system. The stage-2 RO system is a deeper purification system for the stage-1. This kind of system is suitable for poor quality raw water or particularly use for higher water quality requirement.

Pretreatment system is normally composed of quartz sand filter, activated carbon filter, soften filter and precision filter. The mainly working purpose is to protect the following RO membrane by separating large particle pollutants such as sediments, colloid, suspended solids, pesticides, especially residual chlorne and organism from the raw water. And softening equipment is needed to protect the following RO membrane from scaling and block if the raw water is of high Ca2+ or Mg2+ ion content.

RO host is the key part of the whole system as it determines the output water quality. The RO host mainly consists of booster pumps, membrane shell, RO membrane, control circuit and so on. The salinity filtering ability of a single RO membrane can be above 99%. The conductivity of stage-1 RO water will be within 10μs/cm(25℃), and stage-2 RO water will be of less than 5μs/cm(25℃) if with reasonable design. So the design reasonability will directly determine the cost-effective and operating convenience of the system. And power-saving, operating pressure, desalination rate, saltness of output water and receovery rate should be taken into consideration during design process.

And PH regulating system is need for a two stage RO system. As the RO membrane could reduce little CO2, the output water of RO system is acidic. We adopted PH regulating system to control the acidic first stage RO water to weakly basic, so that the second stage RO water will be neutral. PH regulating system is composed of chemical tank, dosing pump, relative valves and pipes. 

The pre-treated water couldn’t come into the RO system unless the SDI is less than 4. And after RO processing, pure water(desalted water) will come into the storage tank, stage-1 concentrate water will be discharged and stage-2 concentrate water will be recycled to raw water system so as to increase the receovery rate.

Ozone sterilizer is installed to inhibit the bacteria, and also to keep the water fresh. And 
UV sterilizer is equipped for sterilization and disinfection, meanwhile to resolve the extra ozone.

Processing Technology

Operation Parameters



Raw Water

Tap water or groundwater (Conductivity ≤ 400μS/cm)

Output Water

conductivity ≤ 10μS/cm


65% - 75%


Auto operation, back washing at regular time

Back Washing Frequency

Vary between 1 to 3 days according to the input water quality

Chemical Washing Frequency

According to the membrane material and polluted situation


Compact construction, stable operation and reliable output water

6/MN, Block 9C,Baoneng Technology Park,Qingxiang Road, Longhua New District, Shenzhen, 518109, CHINA
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