| Membrane-free electrodeionization(MFEDI) is a new technique for high purity water production. This thesis studied the performance of reverse osmosis/decarbonator/ membrane-free electrodeionization(RO/D/MFEDI) stystem for high purity water production. Major research works included the following parts: compare RO/D/MFEDI system and RO/MFEDI system in the ability of high pure water preparation, and put forward the advantage of RO/D/MFEDI system; Set system energy consumption as the inspection standard, and select the best resin device combination and bed structure of MFEDI. Review electric regeneration performance of MFEDI.According to the results, compared to the RO/MFEDI, the MFEDI of RO/D/MFEDI has better capacity in the system and stronger electric regeneration performance. RO/D/MFEDI system continues to run 350 hours, with conductivity 160-200 us/cm tap water as raw water, made of 33650 L high pure water. The conductivity of product is 0.058～0.060μs/cm. The electric regeneration voltage of MFEDI stays between 840 v and 880 v, and the concentrate conductivity keeps in 45～50μs/cm.RO/D/MFEDI system has stronge operation stability.It was shown that 650C-550A determined the MFEDI overall performance, in high speed running of RO/D/MFEDI system. When the ratio of 650C-550A was 1:1.75 and the height of it was 30 cm, regenerative current density 200A/m2, regenerative velocity 35 m/h, the water recovery of MFEDI was 90%, enrichment ratio of concentrate was 10 times, the system achieved the lowest energy consumption:0.45 kWh/m3. Under the condition, the regeneration voltage of MFEDI keeped stability, and the cation and anion of resin absorbed got good regeneration.Compared to RO/EDI, RO/D/MFEDI gets rid of the limitation of the ion exchange membrane and simplifies the installation and operation process. Compared to RO/EDI, RO/D/MFEDI needs not to add alkali liquor in the water, saving the cost, and more green and environmental protection, which demonstrates MFEDI has a bright industrial prospect. |
PDF Full Text Request