乙烯基硅橡胶膜萃取含盐废水中正戊酸

发布时间：2018-08-12 17:13

【摘要】：通过溶胀性能、表面性能测定对比聚二甲基硅氧烷(PDMS)膜管和聚甲基乙烯基硅氧烷(PVMS)膜管在萃取正戊酸前后的特性变化及其自身差异,结果发现,PVMS膜的接触角和溶胀度均高于PDMS膜。膜萃取正戊酸后,膜的化学结构发生了变化,PVMS膜更利于小分子物质通过。以PVMS膜为研究对象,考察了料液浓度、料液流速、萃取液种类对渗透萃取正戊酸过程的影响,讨论了乙烯基硅橡胶膜从含盐废水中分离低分子有机酸的机理,并优化其工艺条件。结果表明:随着料液浓度的提高,正戊酸的去除率和回收率先增加后减小,当料液中正戊酸质量分数为7%时,去除率最大可达为94%;当料液中正戊酸质量分数为2%时,回收率最大达到45.8%。相比于水作萃取液,碱性萃取液将传质提高近1倍,且碳酸钠作萃取液具有更好的适用性。流速在1~20 mL/min时,增大料液流速,正戊酸的去除率和回收率都增加,可在实际应用中适当增大流速来增强分离效果。
[Abstract]:The swelling properties and surface properties of polydimethylsiloxane (PDMS) tube and polymethyl vinyl siloxane (PVMS) membrane tube before and after extraction of pentanoic acid were measured and compared. The results showed that the contact angle and swelling degree of PVMs membrane were higher than that of PDMS membrane. After extraction of n-valeric acid by membrane, the chemical structure of the membrane changed. PVMS membrane was more favorable for the passage of small molecules. Taking PVMS membrane as the research object, the effects of feed concentration, feed flow rate and extraction liquid type on the process of osmotic extraction of n-valeric acid were investigated. The mechanism of separation of low molecular organic acids from salt-containing wastewater by vinyl silicone rubber membrane was discussed. The process conditions were optimized. The results showed that with the increase of feed concentration, the removal rate and recovery rate of n-valeric acid increased first and then decreased. When the mass fraction of n-valeric acid in feed solution was 7, the maximum removal rate was 94%, and when the mass fraction of pentanoic acid in feed solution was 2%, The maximum recovery was 45.8%. Compared with water as extractant, alkaline extraction solution can increase mass transfer by nearly twice, and sodium carbonate is more suitable for extraction. When the flow rate is 1 ~ 20 mL/min, the removal rate and recovery rate of n-valeric acid increase with the increase of feed flow rate, which can be used to enhance the separation effect by increasing the flow rate properly in practical application.
【作者单位】：陕西科技大学环境科学与工程学院;
【基金】：陕西省科技统筹创新项目(2013KTCL14) 陕西省自然科学基础研究计划项目(2015JM4127)~~
【分类号】：TQ028.8;X703

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