新兴萃取技术处理废水中低浓度Cr(Ⅵ)的研究进展

Review of Emerging Extraction Technologies for Treatment of Low Concentration Cr(Ⅵ) in Wastewater

随着国民经济的快速发展,铬资源的使用量日益增多,含铬废水的排放量也随之增加。Cr(Ⅵ)具有致癌性、致畸性和诱变性,如不加以治理将严重污染生态环境,并威胁人类健康。本文系统综述了新兴萃取技术处理废水中低浓度Cr(Ⅵ)的研究进展。传统萃取剂具有易乳化、易挥发及选择性低等缺点,液膜萃取、固相萃取、磁萃取和微流体萃取等新兴萃取技术与传统溶剂萃取(混合澄清萃取、离心萃取和塔式萃取)、化学沉淀、电化学法、膜分离、离子交换、光催化、吸附及生物等技术相比,其不仅能够高效处理含低浓度Cr(Ⅵ)的废水,使其达标排放,还可实现铬资源的回收再利用,符合可持续发展的理念。上述新兴萃取技术尚处于实验室研究阶段,未来必须在绿色萃取剂和新型萃取设备研发方面取得重大突破方可实现工业化应用。

With the rapid development of national economy, the chromium resources usage is increasing day by day, and the discharge of wastewater containing Cr(Ⅵ) is also increasing greatly. Cr(Ⅵ) has the characteristics of carcinogenicity, teratogenicity and mutagenicity.If it is not well treated, Cr(Ⅵ) will seriously pollute the ecological environment and threaten human health. In this review, the research progress of low concentration Cr(Ⅵ) treatment in wastewater by emerging extraction technologies was systematically summarized, and the technical difficulties and the research trends in the future were summarized and prospected. The analysis showed that the traditional extractants were easily emulsified, volatile and at low selectivity, and it was extremely urgent to develop a new economical, efficient and green extractants. Compared with the traditional solvent extraction(mixed-settler extraction, centrifugal extraction and tower extraction),chemical precipitation, electrochemistry, membrane separation, ion exchange, photocatalysis, adsorption, etc., these emerging extraction technologies, such as liquid membrane extraction, solid phase extraction, magnetic extraction and microfluid extraction, not only can remove low concentration Cr(Ⅵ) from wastewater, but also can obtain high quality chromium products. They were consistent with the concept of sustainable development. However, the above emerging extraction technologies are still in the laboratory research stage, a major research breakthrough of green extraction agents and new extraction equipments must be made in the future for achieving industrial application.