Reverse Osmosis System Fault Diagnosis ⑤
Attached: Analysis method on membranes element
(1)Witness and comparing weight
Witness
After system is polluted seriously, it may be seen from pressure volume. Open the upper flat of pressure volume to watch the pollution between upper flat of pressure volume and membranes element.
To watch front part pollution: It is serious polluted at this part with pre-treatment filter leak (sand, particles of surfactant carbon), colloid pollution, organic pollution, bio pollution. There is adhesive matter with stench smell.
To watch end pollution: The end of system is polluted seriously of salt-escape construction, and there is rough powder at end of membranes element.
Comparing weight
Membranes element polluted in water channel has more weight. To dry membranes element and compare with data from manufacturer, the more weight is pollution.
(2) Performance test
The test bay be operated before membranes element disintegration. But when it is confirmed pollution, it shall be analyzed without performance test. So if there are two samples, one is used as performance test and another is used for directly disintegration.
Next items must be inspected:
● Keeping test under vacuum condition and water density
Membranes element. flat membranes destroyed and location.
● To test on salt-escape, water-output and different pressure with standard inspection liquid.
To confirm membranes destroyed, membranes performance down and flow channel plugging and connection tube well or not.
With the above-mentioned data comparing, to find change situation. Inspecting pressure different with different pressure meter to a 1KPa data.
(3) Anatomy
A, Shooting whole and two sections photo of membranes element
B, Take-off two covers and note direction of flow
C, Tear glass steel fiber of overall layer
D, Open assembly of membranes and shooting proper photos which shall be noted at relative location.
E, Against to large area of pollution, is shall be collected to be analyzed. For membranes surface , the photo size may be
(4) Staining
Staining test will be carried above membranes element location. But for analysis pollution, other sample may be optioned.
Dye: Direct blue with molecular of 1000 or ultra violet with molecular of 300
Concentration : Proper volume
Pressure: Test pressure on the membranes element
Time : for 10 minutes
(5) Infrared spectrum FT-IR
Based on FT-IR analysis, to find following data:
A, Membranes performance level of chemical change
After comparing with new membranes spectrum, to know chemical change of membranes beside pollution on membranes surface.
B, Distinguish membranes pollution
After comparing with new membranes spectrum, to find the absorbing curve of pollution matter and guess the main content.
If pollution may be collected, to measure composition of pollution directly through FT-IR.
C, To decide the composition of pollution are float matter, colloid(metal oxide, microbiology, coagulation) or deposition(calcium, silicon and barium sulfate).
D, Fastened adhesive matter on membranes
For a thin layer of adhesive pollution, FT-IR analysis index is 100µm. It may be distilled through large sum of upper clean water, to inspect through T-IR after reducing pressure of distillation concentration. Please advisory expert about composition of adhesive matter.
E, The method of FT-IR must be combined with XMA and other result in order to analysis and find its data.
(6), Scan electric mirror SEM and X-ray XMA
Via electric mirror SEM and X-ray XMA to gain following information:
A, SEM method may watch surface of membranes and pollution and destroyed degree of membranes, and more, find type and situation of crystallization or non-crystallization, bacteria deposition. Through SEM method may watch pollution level.
B, Via XMA method to guess the inorganic matter of pollution attached to membranes, (e.g. element above carbon Amu).
Attached element relative to compound of FT-IR method may be guessed out composition of pollution. e.g. find Si and Fe via XMA method, find algae via SEM and find Si, Fe and microbiology via FT-IR method. Reference to standard spectrum to find Si, Fe and other algae.
★ There are Fe and Al in water-input.
There are H2S in water-input and air entrance, it creates sulfate, if connected
★ with air, it will create deposition of elemental S.
Parts of tube, pressure volume and front end of membranes are corrosive