1. The filter material must meet the standard. The filter material is usually made of quartz sand or activated carbon. The chemical stability of the filter material in acidic, alkaline and neutral solutions shall be tested. After soaking for 24 hours, it shall be filled. Strict standards shall be met. For example, the increase of total solid content shall not exceed 20mg / L and the increase of oxygen consumption shall not exceed 10mg / L.
2. After the filter is loaded, the inlet and outlet pressure difference shall be observed according to the flow rate of 5-8m / h. the filter material must be carefully checked and cleaned before loading into the equipment. The water flow is washed from bottom to top, and the dirty water shall be discharged from the upper sewage outlet.
3. The effluent of material transfer flushing shall be clarified so that it can be put into operation. At the same time, it shall be observed whether the effluent is clarified. If it is clarified, it can be used as normal effluent. The effluent shall be observed once every hour. If it is found that the water quality does not meet the requirements, it shall be stopped immediately and backwashed.
4. During backwashing, first close the water inlet gate and open the blowdown gate to lower the water surface to the position of the mirror tube. At this time, close the blowdown gate, open the compressed air gate and emptying gate, compress the air to the bottom, loosen the filter layer for 3-5 minutes, and discharge the gas from the emptying valve. Then slowly open the backwash inlet gate, and the water will flow in from the bottom until the air gate overflows. Immediately close the air gate and open the blowdown gate. The water will be discharged from the upper part, and the flow will gradually increase to ensure a certain backwash degree.
5. When cleaning, the water inlet and drain valves must be opened first. Wash with water from top to bottom. The cleaning flow rate is 5 meters per hour and the cleaning time is 5-10 minutes. If the outlet water is transparent, close the blowdown gate and open the outlet gate to start normal operation.
6. If there is sand flowing, there should be no sand flowing during backwashing. If clean water cannot be seen even after the backwashing time exceeds the specified value, overhaul the equipment