环境中六溴环十二烷的修复技术研究进展

Advances in Environmental Remediation Technologies for Hexabromocyclododecane

六溴环十二烷(hexabromocyclododecane,HBCD)是一种非芳香的溴代环烷烃,作为阻燃剂被广泛应用于塑料、泡沫、纤维、纺织品、电子产品及其他有机材料中,也可以作为聚乙烯、聚碳酸酯、不饱和聚酯等塑料的阻燃添加剂。HBCD作为一种持久性有机污染物,能够在环境中长期积累、迁移和转化,对人类和环境构成潜在的的危害。随着全球HBCD用量的增加,HBCD造成的水体及土壤的污染也越来越严重,因此环境中HBCD修复技术的研究也日益成为各个国家和地区研究的热点之一。文章综述了近年来国内外关于HBCD的去除或降解技术,包括物理修复、化学修复和生物修复,同时阐述了各个修复方法的原理、条件及优缺点。重点介绍了光降解和微生物降解这两种修复方法:光降解是一种利用光照和催化剂使水体中HBCD发生降解的修复方法,该方法去除效率高、清洁环保,但发生条件高,并且成本较高;微生物降解是指利用环境中的某种微生物来实现HBCD降解的,HBCD在厌氧条件下的降解效率明显高于好氧的条件,微生物降解具有不产生二次污染、降解彻底等优点,但相关研究还很少,发展还不成熟。目前开展HBCD植物修复研究的报道也很少,因此探讨利用植物修复HBCD的研究应该成为今后此类工作的研究重点之一。关于未来HBCD修复研究的方向,作者认为光降解和微生物降解仍然是HBCD修复的主要研究重点;还可以尝试采用两种或两种以上的修复方法联用以达到满意的修复效果;另外,微生物共代谢等修复方法也是今后发展的主要方向。

Hexabromocyclododecane （HBCD） is a kind of brominated flame retardants （BRFs）, widely used in plastics, foams, fibers, textiles, electronic products, and other organic materials. It can also be used as flame retardant additives in PE, polycarbonate, and unsaturated polyester plastics. This material has abilities of long-term accumulation, migration, and transformation as one of persistent organic pollutants （pops） in the environment, exerting a potential threat to human beings. The recent increasing usage of HBCD even make the situation worse. Technologies of removing HBCD in the environment have drawn much attention around the world. The recent domestic and abroad HBCD removal and degradation techniques, including physical remediation, chemical remediation, and bioremediation, are reviewed in this paper. The principles, applicable conditions, and pros and cons of the three methods are also discussed. Photo-degradation and microbial degradation are described in details. Utilizing light and catalyst in water, photo-degradation has advantages of high efficiency and clean environment, with drawbacks of critical conditions and high costs. Microbial degradation uses certain microorganisms to achieve HBCD degradation, and the degrading efficiency under anaerobic conditions is significantly higher than under aerobic conditions. This method does not produce secondary pollution. However, the development is not mature with few studies. The current HBCD phytoremediation is rarely reported. The usage of phytoremediation on HBCD should be focus of such research efforts in the future. The authors hold that the photo-degradation and microbial degradation shall be the main developing methods. Or the two above methods can be combined to acquire a better result. Microbial metabolism method is a promising technique for future development.