PBDEs的来源特征、环境分布及污染控制

多溴联苯醚(Polybrominated diphenyl ethers,PBDEs)生产应用、环境分布与生态风险之间的关系将如何影响我国的未来,具体涉及到工业、环境、健康、人类繁衍等的社会问题.由于PBDEs阻燃效率高,热稳定性好,价格便宜,作为添加剂被广泛应用在电子、电器、化工、交通、建材、纺织、石油等领域的阻燃产品中.PBDEs进入环境后迁移扩散并富集于沉积物和生物体内,进入人体后引起肝脏毒性、内分泌干扰、神经毒性和生育能力下降等而危害人类的健康.基于此,从生产应用、品种生产量、分子的物理化学特性以及毒性等的文献数据分析了PBDEs的来源特征与环境危害,分析这些性质对环境分布与污染控制的基础支持关系;从沉积物、水体、大气、水生生物、人体5个方面考察了PBDEs的环境本底浓度变化、分配关系、迁移规律、时间效应,分析了生产、应用与扩散的多因素影响关系,发现全球性PBDEs污染物蔓延的现象,沉积物是主要的归趋场所,室内空气中的浓度远高于室外,水中浓度较低,水生生物和人体均能富集PBDEs,通过饮食、母乳和呼吸摄入,可实现代际传播,污染的分布呈现介质与区域的不同特征;污染控制需要考虑点源技术与面源修复的联合,结合PBDEs的物理性质、分子结构及其化学特性,统计分析了微生物法、光化学降解法和零价铁还原法的原理及其有效性,根据PBDEs在产品中存在与分布的特点,提出收集-分离-富集-超临界催化还原和氧化毁毒的工艺,针对实际环境(以电子垃圾塑料和流域水体及沉积物为对象)中的PBDEs进行回收或处理,结合材料如催化剂的应用,从动力学和热力学方面提高PBDEs无害化的效率.最后,从生产管理、环境监测、风险评价、技术集成等方面提出了未来的努力方向.

Source, characteristics, environmental distribution and pollution control of PBDEs

The influence on the future of our country by the application, environmental distribution and ecological risk of Polybrominated diphenyl ethers (PBDEs) is a social issue, particularly concerning about industry, environment, health and human reproduction. Due to their high flame retardant efficiency, excellent thermal stability and low price, PBDEs are widely used as flame retardant additive in many fields including electronics, electrical appliances, chemical industry, transportation, building materials, textile and oil industry. Once PBDEs were discharged into the environment, they can migrate and accumulate in the sediments and organisms, enter human body and harm to human health by endocrine disturbance, liver toxicity, neurotoxicity and fertility falling. Thus, this review focuses on the source, characteristics and environmental impact of PBDEs by analyzing literatures about PBDEs' production and application, physical and chemical characteristics and toxicity. the environmental background concentrations, distribution, migration and time effect of PBDEs from five aspects, i.e. sediments, water, atmospheric, aquatic organisms and human body, were studied and the results indicate that the spread of PBDEs pollutants is a global phenomenon. sediment is a main place for the fate of PBDEs. the indoor concentration of PBDEs is higher than outdoor. The concentration of PBDEs in water is low, and both aquatic organisms and human body can accumulate PBDEs by the intergenerational transmission through the diet, milk intake and breathing the pollution distribution of PBDE was different among various medium and area. Pollution control of PBDEs needs combining the point and non-point source remediation. Based on the physical properties, molecular structure and chemical properties of PBDEs, the mechanisms and the effectiveness of different technologies, such as microbial process, photochemical degradation and zero-valent iron reduction, for PBDEs degradation are analyzed. According to the characteristics and distribution of PBDEs, the technology of coupling sample collection, separation, enrichment with catalytic supercritical water reduction and oxidation is proposed for complete mineralization of PBDEs from electronic wastes, water and sediment of the basin river. Prior to application, optimizing the performance of the catalyst, the feasibility of PBDEs removal in the aspects of kinetics and thermodynamics and the relationships between molecular properties and relevant control strategies were elucidated. In all, the future management, environmental monitoring, risk assessment and technology integration of PBDEs were proposed.