In most cases, changes in permeate flow, desalination rate, and pressure drop are symptoms associated with certain specific causes of failure. Although different causes of failure in a real system may repeat the same symptoms, in many specific cases, individual symptoms play a more dominant role. Below is a summary of some common symptoms, possible causes, and corrective measures.
|
Fault symptoms |
Direct cause |
Indirect causes |
Solution |
||
|
Water production flow rate |
Salt permeability |
Pressure difference |
|||
|
↑ |
⇐ |
→ |
Oxidative damage |
Residual chlorine, ozone, KMnO4, etc. |
Replace membrane element |
|
↑ |
⇐ |
→ |
Membrane leakage |
Product water back pressure Diaphragm wear |
Replace membrane element Improve the filtration effect of security filters |
|
↑ |
⇐ |
→ |
O-ring leakage |
Incorrect installation |
Replace O-rings |
|
↑ |
⇐ |
→ |
Leakage in the water production pipe |
Damage during component assembly |
Replace membrane element |
|
⇒ |
↑ |
↑ |
Scale |
Improper scaling control |
Cleaning: Controlling scaling |
|
⇒ |
↑ |
↑ |
Colloid pollution |
Improper pretreatment |
Cleaning: Improved pretreatment |
|
↓ |
→ |
⇐ |
Biological pollution |
Raw water contains microorganisms, Improper pretreatment |
Cleaning: Disinfection Improved preprocessing |
|
⇒ |
→ |
→ |
Organic pollution |
Oil, cationic polyelectrolytes |
Cleaning: Improved pretreatment |
|
⇒ |
↓ |
→ |
Compacting |
Water hammer effect |
Replace or add membrane elements |
