1. The new membrane element
(1) Membrane elements have been tested before delivery, and the use of 1% sodium sulfite solution for storage treatment, and then with oxygen isolation bag vacuum packaging.
(2) The membrane element must be kept moist at all times. Even if it needs to be opened temporarily in order to confirm the quantity of the same package, it must be done in a state that does not damage the plastic bag, and this state should be kept until the time of use.
(3) Membrane elements are best stored in 5~10℃ at low temperature. When storing in an environment where the temperature exceeds 10℃, choose a well-ventilated place and avoid direct sunlight. The storage temperature should not exceed 35℃.
(4) If the membrane element freezes, physical damage will occur, so insulation measures should be taken, do not make it freeze.
(5) When stacking membrane components, the packing boxes should not exceed 5 layers and ensure that the cartons are kept dry.
2. Used membrane element
(1) Membrane elements must always be kept in a dark place, the storage temperature does not exceed 35℃, and to avoid direct sunlight.
(2) There is a risk of freezing when the temperature is below 0℃, so anti-freezing measures should be taken.
(3) In order to prevent microbial growth of membrane components during short-term storage, transportation, and system standby, sodium sulfite (food grade) protective solution with concentration of 500~1,000ppm, pH3~6, is prepared with pure water or reverse osmosis production water. Typically, Na2S2O5 is used, which reacts with water to form bisulfite: Na2S2O5+H2O -- 2NaHSO3.
(4) After soaking the membrane element in the preservation solution for about 1 hour, remove the membrane element from the solution and pack it in an oxygen isolation bag. Seal the bag and label it with the packing date.
(5) After the membrane element to be saved is repackaged, the preservation conditions are consistent with those of the new membrane element.
(6) The concentration and pH of the preservation solution should be kept in the above range, which should be checked regularly. If deviation from the above range is possible, the preservation solution should be modulated again.
(7) Under no circumstances should the membrane be left in a dry state for preservation.
(8) In addition, formaldehyde solution with concentration (mass percentage concentration) of 0.2-0.3% can also be used as preservation solution. Formaldehyde is a stronger microbial killer than sodium bisulfite and does not contain oxygen.
