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DTRO Membrane System Pretreatment
- Aug 30, 2018 -

DTRO membrane system pretreatment


Due to its different factory conditions and pre-treatment processes, high-concentration wastewater has complex composition and various kinds of insoluble salts such as calcium, magnesium, barium and silicon. These insoluble inorganic salts are concentrated in high-concentration after entering the reverse osmosis system. When the concentration exceeds the solubility under the conditions, fouling will occur on the surface of the membrane. Adjusting the pH value of the raw water can effectively prevent the scaling of the carbonate inorganic salt, so the pH of the raw water must be adjusted before entering the reverse osmosis.


Adjusting the water pump of the tank into the raw water tank of the reverse osmosis system, adjusting the pH by adding acid in the raw water tank, and the effluent of the raw water tank is pressurized by the original water pump and then enters the quartz sand filter, and the number of the sand filter is determined according to the specific treatment scale, The filtration accuracy is 50 μm. There are pressure gauges at the inlet and outlet of the sand filter. When the pressure difference exceeds 2.5 bar, the backwashing procedure must be performed. The frequency of backwashing of the sand filter depends on the suspended matter content of the influent water. For general wastewater, the backwashing period of the sand filter is about 100 hours. For the raw water with a relatively low SS value, if the pressure difference is not 100 hours after the sand filter operation, Backwashing is also required over 2.5 bar to avoid excessive compaction and squashing of the quartz sand, which automatically activates the sand filter backwash time on a first-come time basis. The sand filter is washed with raw water; the air is washed with compressed air generated by a rotary vane compressor.


After the sand is filtered out, the water enters the core filter. For the leachate level system, due to the high level of easily scalding ions and silicates such as calcium, magnesium and barium in the raw water, these salts are easily concentrated in the concentrate after high concentration of the DT membrane module. There is supersaturation on the side, so according to the actual water quality, a certain amount of scale inhibitor is added before the core filter to prevent the occurrence of silicon scale and sulfate scale. The specific addition amount is determined by the analysis of raw water quality, and the scale inhibitor should be Add 20 times of water for dilution and use. The core filter provides the last protective barrier for the membrane column with a core filter with an accuracy of 10 μm. Similarly, the number of core filters is determined by the specific treatment scale as well as sand filtration.