圖書典藏及影音數位平台

水利署於104-105年辦理「再生能源於再生水廠之應用研究」，建立0.2 CMD級平板式薄膜蒸餾(MD)系統，並以迪化污水處理廠實廠持續操作四個月取得相關研發數據，完成其產水成本、水質評估，達成造水與節能之目標。 由於能源及資源未來將成為重要之戰略物資，因此本計畫除著重於再生水廠除造水與節能外，並以開發為具有造水、節能、創能與能資源之全回收系統，另結合研發單位、系統製造商、用水端開發具本土智財權薄膜，以商品化為前提進行噸級模廠設計及測試，加強各界對我國再生水科技的印象，以促進再生水產業發展。 本計畫考量目前商業化RO產水率仍有約50-70%的濃排液，如能將MD運用於提升再生水廠或海淡廠中RO濃縮液之濃度，除可將濃排液進一步減量，並更可與正滲透(FO)系統搭配成為壓力延遲滲透(PRO)系統，利用滲透壓差提高濃液之位能，再藉由高度差進行發電，除了可以降低再生水廠或海淡廠用電量，達到減碳效果，另也可再利用支撐式液態薄膜(SLM)將MD與RO濃排液中的有價金屬資源進行回收，惟目前我國並無上述整合各技術之系統及試驗成果，故本計畫針對RO濃排液再利用、發電以及有價資源回收之發展進行研究。

The purpose of this project was to establish the integration of membrane processes of membrane distillation (MD), pressure retarded osmosis(PRO) and supported liquid membrane (SLM) for reclaimed water and/or concentrated liquid treatment, and also assist the WRA to evaluate the feasibility of using the membrane technologies for approaching total recovery of water, resource and energy by low-emission carbon system. This year, the project mainly focused on the pilot test. In the MD part, a petrochemical plant in Kaohsiung was selected to build a MD pilot plant. The plant’s warm waste water with a temperature ranging from 54 to 60 oC was used as feed for the production of 1CMD water. Experimental results show that the trace amount of PVA(polyvinyl alcohol) in the wastewater can be completely rejected. The data of other water quality measurements also showed that the quality of MD water is better than that of RO water. It is worth noting that the MD flux is deeply affected by the packing density of membrane in the module. For the 6-inch module used for the test, the MD flux decreased from 5.3 to 3.8 LMH when the tubular membranes area packed was increased from 2 to 6.8 m2. Based on the flux from 3.8 to 5.0 LMH, the cost of producing water by MD was estimated to be about NT$ 36.5~29.3/m3. Based on the results of pilot tests, the project also carried out the MD process design for 200 CMD water production, and estimated the specification requirements of the units for the process. On the other hand, MD tests were also carried out at Taoyuan North district reclaimed water center. Experimental results with membrane bioreactor effluent as feed for MD test showed, four types of solutions such as NaOH ( 1 wt% ), Citric Acid ( 1 wt%), NaOCl ( 0.1 wt% ) and Deionizer water used for crossflow over the fouled membrane to test the cleaning performance, all can restore the flux to near the initial flux of virgin membrane. When the RO concentrate was used as the feed for the MD test, feed temperature at 60 ° C and permeate side temperature at 30 ° C, the flux decays to about 50% after 16 hrs operation, which means that there is obvious membrane fouling growth. The produced water quality test including Cl- concentration, electrical conductivity, dissolved oxygen, SS, total phosphorus, hardness and E. coli, etc. showed the MD water has a better quality to that of RO water. After 24 hr continuous MD operation with RO concentrate, it is more effective to recover the flux by washing the fouled membrane with citric acid solution. In the PRO part, this project continued the development of high-flux FO membrane. With 2M Na2SO4 as the draw solution for FO test, the water flux of tubular membrane fabricated in the study can reach 80 LMH, but its salt reverse rate was also high to 2g MH, thus limiting the application of the membrane to PRO process. The PRO test was carried out on a self-prepared PSf/polyamide tubular membrane, and the results showed that the performance remained stable after a long period of operation. In the SLM section, the tin-indium waste liquid and the copper-containing high salinity waste liquid form Guanyin Industrial Zone were tested. The test results showed that under the condition of 0.5M D2EHPA as extractant and 5N H2SO4 as stripping agent, the purity of tin in the stripping agent can reach over 98% and the concentration of tin is about 30,000 ppm. For the high salinity waste liquid containing copper, 20v% LIX984-N was used as the extract solution and 3M H2SO4 was used as the stripping solution. After 20 minutes of operation, the extraction and stripping efficiency of copper ion reached 80% and 90%, respectively. The copper ion concentration in the stripping stream was 2179 ppm.