| Popis: |
After purification treatment, the circulating cooling wastewater from a certain thermal power plant was reused. However, malfunction occurred during the operation of the reverse osmosis (RO) membrane unit in the purification treatment system, resulting in a rapid increase of pressure difference between the RO sections and a decrease of water production and desalination rates. Through analysis of inlet water quality of reverse osmosis, changes in the water source of circulating cooling system, membrane element standard testing, membrane element dissection, membrane staining test, foulants burning weight loss analysis, and foulants component identification, etc., the cause of malfunction of RO membrane unit was analyzed. The results indicated that after using urban reclaimed water as influent of circulating cooling system, the concentrated wastewater from the circulating cooling system contained high levels of organic matter, calcium and magnesium ions, phosphate ions, and alkalinity, which were the main causes of reverse osmosis membrane fouling. Membrane foulants were mainly composed of inorganic phosphate fouling, with organic fouling as a secondary component, accompanied by fouling such as silicon fouling and iron fouling. Measures such as adding alkali dosing devices and non-oxidizing bactericide dosing device, repairing sulfuric acid dosing device, and thoroughly offline chemical cleaning of reverse osmosis membranes were taken to restore normal operation of the reverse osmosis system, effectively solving the problem of frequent fouling and blockage of the reverse osmosis membrane during operation. |
