共查询到19条相似文献,搜索用时 171 毫秒
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反渗透技术处理压水堆一回路放射性废水试验研究 总被引:1,自引:0,他引:1
选用聚酰胺反渗透膜处理核电站一回路放射性废水.对反渗透去除核电站一回路放射性废水及反应堆停堆换料期间一回路排水中的钴离子进行研究.在不同操作压力及浓度下,考察废水中硼酸及镍离子对稳定核素钴的截留率影响.研究表明,一回路废水中含有的硼酸会降低反渗透对钴的截留率,硼酸质量浓度由2 500 mg·L-1下降到500 mg·L-1时,去除率由79.3%上升到88.8%.截留率及膜通量随着膜面压力上升而升高,在1.4 MPa时分别达到86%及30m3·m-2·s-1.结果说明反渗透技术可以有效地去除核电站放射性废水中的钴元素,并且可以获得稳定的膜通量. 相似文献
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本文综合阐述了采用微滤-纳滤-高压反渗透-超高压反渗透组合工艺浓缩燃煤电厂湿法脱硫废水的工艺流程、参数等。以连续运行方式考察了各级膜的浓缩性能和污染物的截留情况,结果表明膜组合工艺能够有效截留水中的溶解性污染物,且产水水质稳定达到电厂回用水要求。脱硫废水中的氯离子等盐分浓缩3.5倍,使进入后续蒸发工艺的水量减少60%以上,并有效分离水中的二价盐和单价盐,得到含有高纯度NaCl的浓盐水。浓缩液的总溶解性固体(TDS)达到100 000 mg/L以上,替代蒸发浓缩工艺实现了脱硫废水的高倍浓缩。 相似文献
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超滤法分离纯化刺参酸性粘多糖工艺研究 总被引:4,自引:1,他引:3
探索了超滤法分离纯化刺参酸性粘多糖的工艺.确定分离纯化条件为:采用截留分子量8 kDa的超滤膜,压力为0.3 MPa,温度为10℃.此工艺制得多糖纯度为93.4%、收率为0.32%,多糖截留率达到97.2%. 相似文献
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Grits, flour, degerminated meal and hominy feed from corn were fermented to make ethyl alcohol. The stillage, remaining after
distillation of alcohol, was separated by screening and centrifuging into insoluble and soluble fractions. The stillage solubles
contained 0.036 to 0.080% nitrogen and 1.4 to 7.2% total solids. Ultrafiltration (UF) membranes separated stillage solubles
into permeate and concentrate fractions. Permeates from stillage solubles accounted for 85 to 95% of the original volume,
44 to 67% of the total solids and 40 to 75% of the total nitrogen. Reverse osmosis (RO) membranes separated the UF permeate
into RO permeate and RO concentrate fractions. The RO permeate accounted for 70 to 92% of the original volume, 5 to 15% of
the total solids and 5 to 21% of the total nitrogen in the UF permeate. Conductivity of some RO permeate fractions was lower
than that of tap water. The combination of UF and RO processing of stillage solubles from corn dry-milled fractions appears
to be an attractive method to recover most of the solids and nitrogen in small volumes of concentrate, and produces a final
permeate with a low concentration of solids and nitrogen. The RO permeate may be reused as water, treated further or discharged.
Presented at the AOCS Annual Meeting, May 1984, Dallas, Texas.
Deceased. 相似文献
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T. Venkatesh 《分离科学与技术》2017,52(14):2262-2273
The membrane-based grey water treatment for grey water reuse and surfactant recovery is presented in this research paper. Grey water from washing machine discharges having turbidity and used surfactant was processed through the polymeric ultrafiltration (UF) membrane to remove the turbidity. The UF treated grey water is further purified by reverse osmosis (RO) membrane for surfactant recovery and water reuse. The surfactant trapped inside the RO spiral wound membrane module is recovered through various membrane physical regeneration techniques such as backwashing, simultaneous backwash–back-flush and ozone back-flush. Among this, backwash–back-flush is found to be effective process for surfactant recovery. The methodology for optimising surfactant recovery is captured by studying effect of various operating parameters such as feed detergent concentration, backwash pressure, backwash temperature and back-flush flow rate. By implementing optimal process conditions, the integrated UF and RO membrane process is able to produce 300 L of reusable pure water and 80 L of concentrated detergent solution and 20 L of turbid water while treating 400 L of grey water discharges. Maximum surfactant recovery of 82% is obtained while treating grey water which consists of 720 ppm of total dissolved solids (detergent) and 45 ppm of surfactant. The extent of UF and RO membrane fouling is determined by measuring the pure water flux before and after the grey water treatment. The membrane performance is found to be stable when membrane is regenerated by backwash–back-flush technique for RO and gravity backwash for UF membrane. 相似文献
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Camila Baldasso Lídia K. Lazzari Bianca S. Scopel Ligia D.F. Marczak Isabel C. Tessaro 《分离科学与技术》2016,51(11):1862-1871
The aim of this work is to improve the utilisation of fractions of whey through membrane separation processes. From a solution of whey treated by ultrafiltration (UF) associated with diafiltration (DF), two streams were obtained: a concentrate and a permeate. In this process, a purified protein concentrate with about 70% of protein was obtained. Permeate was treated by electrodialysis (ED) to obtain a fraction rich in lactose (90%). The final effluent was treated by reverse osmosis (RO) in order to recover water free of salts. RO made it possible to recover 50% water and retain 85% of the salts. 相似文献
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Conventional water reclamation processes, such as membrane bioreactors, are not always effective in removal of pharmaceuticals and personal care products (PPCPs), endocrine disrupting chemicals (EDCs) and/or N-nitrosodimethylamine (NDMA), even with the reverse osmosis (RO) membrane process. A study was conducted, at a NEWater factory in Singapore, to compare a conventional ultrafiltration (UF) membrane /RO treatment process with a treatment train having the HiPOx unit, an advanced oxidation process (AOP), which was installed between the UF and the RO unit operations. By incorporating the HiPOx into the UF/RO treatment process, following results were observed; 1) increased removal of PPCPs, EDCs and NDMA, 2) improvement in ultraviolet transmission (UVT) of the RO permeate, 3) enhanced removal of TOC and color, and increased UVT of the RO brine, 4) suppression of the increase in the RO transmembrane pressure by organic fouling. 相似文献
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Ismail Koyuncu 《Desalination》2003,155(3):265-275
This paper presents the results of the laboratory and pilot-scale membrane experiments of opium alkaloid processing industry effluents. Different types of ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membranes were evaluated for membrane fouling, permeate flux and their suitability in separating COD, color and conductivity. Experiments demonstrated that membrane treatment is a very promising advanced treatment option for pollution control for opium alkaloid processing industry effluents. Almost complete color removal was achieved with NF and RO membranes. COD and conductivity removals were also greater than 95% and met the current local standards. Nevertheless, pretreatment was an important factor for the NF and RO membrane applications. Membrane fouling occurred with direct NF membrane applications without UF pretreatment. The total estimated cost of the UF and NF treatment system was calculated as $0.96/m3, excluding the concentrate disposal cost. 相似文献
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为解决海水淡化过程中反渗透膜的污染问题,研究了基于正渗透策略的反渗透产水、模拟反渗透浓水、模拟海水不同的组合清洗和清洗时间对膜通量和截留率的影响。针对不可逆污染,研究了不同化学清洗药剂、浸泡时间、浓度对膜通量和截留率的影响。结果表明,正渗透策略清洗方式中,淡水/模拟反渗透浓水的组合清洗方式效果最佳,其归一化通量从9.48 L/(m2·h·MPa)提升至13.6 L/(m2·h·MPa),截留率从80.59%提升至92.80%。此外,经质量分数为2%的柠檬酸溶液浸泡2 h后,再使用质量分数为1%的乙二胺四乙酸四钠盐和0.3%的三聚磷酸钠溶液浸泡1.5 h,其归一化通量从9.48 L/(m2·h·MPa)提升至14.3 L/(m2·h·MPa),截留率从80.59%提升至96.27%。从SEM和AFM图可以看出,正渗透清洗策略并未对膜表面选择层造成损坏,且可以清洗膜表面的有机污染物和无机污染物,因此,应用这种方法对污染的反渗透膜进行清洗,可延长化学清洗周期,减少化学清洗剂用量,具有一定的工业应用前景。 相似文献
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Forward-osmosis strategy and chemical cleaning of seawater desalination reverse osmosis membranes 下载免费PDF全文
In order to settle the membrane fouling of reverse osmosis membranes in seawater desalination process, this study reported a novel strategy based on forward-osmosis process and discussed the effects of different factors like different cleaning combination among reverse osmosis product, simulated reverse osmosis concentrate and simulated seawater, as well as cleaning time on the membrane permeate flux and salt rejection. For irreversible fouling, the effects of different chemical cleaning agents, immersion time and concentration were also investigated in this study. The results exhibited that the cleaning combination between diluted water and simulated reverse osmosis concentrate possessed the best cleaning performance in the process of forward-osmosis cleaning. Such approach also enhanced normalized flux from 9.48 L/(m2·h·MPa) to 13.6 L/(m2·h·MPa) and enhanced NaCl rejection from 80.59% to 92.80%. Furthermore, the normalized flux was enhanced from 9.48 L/(m2·h·MPa) to 14.3 L/(m2·h·MPa) and NaCl rejection was also enhanced from 80.59% to 96.27% after soaking in 2%(mass) citric acid solution for 2h, soaking with 1%(mass) ethylenediamine tetra-acetic acid tetrasodium salt and 0.3%(mass) sodium tripolyphosphate solution for 1.5 h. According to the result of SEM images and AFM images, the forward-osmosis cleaning strategy could not cause the damage of selective layer of membrane surface and caused the drop of inorganic and organic fouling on the membrane surface. Hence, cleaning fouled RO membranes by such approach could prolong the chemical cleaning cycle and reduce the amount of chemical cleaning agent, which has certain industrial application perspectives. 相似文献
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膜分离技术制备高纯单宁酸的研究 总被引:6,自引:0,他引:6
工业单宁酸经改性活性炭预处理后,用超滤和纳滤技术纯化的方法制备高纯度单宁酸。重点考察了料液质量分数、操作压力差、料液温度对膜分离效果的影响。确定的最佳工艺条件是:料液质量分数 15%、截留相对分子质量为 6000 的超滤膜和截留相对分子质量为600的纳滤膜的操作压力差分别为 0.10 MPa 和 0.08 MPa、料液温度 40℃。同时探讨了颗粒活性炭通过硝酸氧化改性增强其吸附性能的方法。分析结果表明,膜分离技术有效地实现了不同分子质量的物料分级和截留,精品单宁酸的含量为 97.3%,收率为 84.7%。 相似文献