沉积物磷原位钝化技术研究进展

Research Progress of Sediments Phosphorus In-situ Inactivation

水体磷含量是湖泊富营养化最主要的限制因子之一。伴随着湖泊流域工农业发展,外源污染物的长期输入致使沉积物中蓄积了大量的磷及其他污染物。湖泊沉积物一方面是水体磷重要的汇,但另一方面还是水体磷重要的源。在单纯控制湖泊外源污染条件下,沉积物磷的释放仍可导致水体持续富营养化,湖水水质得到明显改善通常需要数十年,因此控制湖泊沉积物内源污染释放是快速恢复湖泊水质必不可少的措施。沉积物内源污染控制技术包括生物修复、环保疏浚以及原位钝化技术。受水深等环境条件限制,生物修复技术和环保疏浚在深水、亚深水型湖泊难以实施。沉积物磷原位钝化技术具有生态、经济、快速和效果稳定等特点,在控制湖泊底泥内源污染中可望发挥重要作用,尤其适合于深水、亚深水型湖泊内源污染控制。系统阐述了不同沉积物原位钝化剂的钝化原理,对比分析了铝盐、铁盐、钙盐和粘度矿物作为磷钝化剂的优缺点和应用条件,概述了国内外沉积物原位钝化技术的应用现状,在此基础上提出了沉积物原位钝化技术未来的重点研究方向:一是研究发展新型钝化剂;二是因地制宜,探索适合不同类型湖泊的底泥原位钝化技术体系;三是加强底泥原位钝化技术与其他技术的联合应用研究与示范;四是加强钝化剂负面影响评价,建立科学的应用技术方案。

Phosphorus （P） is one of the limited factors for eutrophication. With the industrial and agricultural development, a large amount of phosphorus and other pollutants enter and accumulate in sediments. Sediments play an important role in overall phosphorus （P） cycling in lake ecosystem, which are thought to act both as a sink and a source of P due to continuous transport of P across the sediment-water interface. Phosphorus can be released from sediments into overlying water under certain environmental conditions, which may have a significant impact on wa- ter quality and result in continuing eutrophication. Under the condition of pure exogenous pollution control, the lake water will be improved in at least tens of years. To improve water quality, it is necessary to promote to reduce phosphorus sources in upstream tributaries and the phosphorus release from sediments. Many methods are used forrestraining of P release from sediments, such as bioremediation, strategic dredging and in-situ inactivation technolo- gy. For the restriction of water depth, bioremediation and strategic dredging can not reduce the P releasing from sediments effectively. Sediments repaired with inactivation agents can improve the water quality. In-situ inactivation technology will play an important role in sediments, especially for the sub-deep lakes sediments, reparation. Inacti- vation agents are used for restraining of P release from sediments ecologically, economically and effectively. Howev- er, the application of one technology can solve a problem, and also brings another problem accordingly. This paper gives a review of recent researches on the sediments in-situ inactivation technology, inactivation mechanism, advan- tages and disadvantages of different inactivation agents, such as aluminum, iron, calcium and natural clay miner- als. Meanwhile, the priority research areas of sediments in-situ inactivation technology are pointed out： The first is to explore novel agents for in-situ inactivation technology; the second is to search new technology system suitable to local conditions for different types of lakes, the third is to strengthen researches of combining applications of sedi- ments inactivation and other technologies; and the last is to strengthen the negative effects assessment of different inactivation technologies, and to find reasonable plans to solve these problems.