Reverse Osmosis Membrane Polluted Reasons Solutions

Zhangjiagang Reliable Machinery Co.,LTD

Reverse osmosis membrane polluted solutions

Phenomenon(Common signs)

  First, the biological fouling Organic deposits are mainly live or dead microorganisms, hydrocarbon derivatives, natural organic polymers and all carbon-containing substances. Initially manifested as an increase in desalination, pressure drop and water production decreased

Solution

(A)Perfect  pretreatment.

Improve the pre-treatment reasons:

(1) Prevent contamination on the surface of the membrane and prevent suspended substances, microorganisms, colloidal substances from attaching to the membrane surface, or fouling of components.

(2) Prevent membrane fouling. Due to the concentration of water, some insoluble salts are deposited on the membrane surface.

(3) Ensure that the membrane from mechanical and chemical damage, to ensure that the membrane performance and adequate use of time.

(B)Cleaning  membrane.

Cleaning principles: understanding of water quality characteristics, chemical analysis of pollutants, choose the best cleaning agents and cleaning methods.

Cleaning conditions:

1. Product water than normal down 5% -10%.

2. After the temperature is corrected, the water supply pressure will increase by 10% -15%.

3. Through the water conductivity (salt content increase) increased by 5% -10%.

4. Multi-stage RO system, through the different sections of the pressure drop increased significantly.

Cleaning method:

System Recoil → Negative Pressure Cleaning → (if necessary) Mechanical Cleaning → Chemical Cleaning → Ultrasonic Cleaning (if possible).

Cleaning steps:

Cleaning single-stage system: configuration of cleaning fluid → low-flow input cleaning fluid → cycle → soak → high-flow pump cycle → flush → restart system

Cleaning for special pollutants include: cleaning sulfate scale, cleaning carbonate scale, cleaning iron and manganese pollution, cleaning organic pollution.

(C)Membrane for maintenance.

1. System outage in the short term (1-3 days).

The first low-pressure (0.2-0.4MPa), large flow flushing. The time is 14-16 minutes.

2. System outage more than a week (ambient temperature above 5 ℃)

The first low-pressure (0.2-0.4MPa), large flow flushing. The time is 14-16 minutes. Configure 0.5% formalin solution, enter low pressure, and circulate for 10 minutes. Close the valve, sealed.

3. Environment temperature below 5 ℃

The first low-pressure (0.2-0.4MPa), large flow flushing. The time is 14-16 minutes.

Conditions, the bad environment can be increased to 5 ℃ above, and then follow the 1 method.

Unconditionally, one-third of the water produced in the system will flow for a long period of time, ensuring the system runs for 2 hours a day. After cleaning, it will be moved to a place where the ambient temperature is above 5 ° C and soaked in 0.5% formalin solution Flip every two days.

(D)Avoid the film running under high pressure.

1. After the equipment is emptied, the gas is quickly run-up without re-running.

2. Clean or replace the micron filter to ensure that the pipeline does not leak.

3. The operation of the normal operation of the pump, the flow rate and the provisions of the same value to determine the operating pressure.

(E)Pay attention to the shutdown operation.

1. Prepare to shut down, step down to 3bar or so with pre-treated water for 14-16 minutes.

2. Preparation shutdown, should stop dosing chemical reagents.