不同污染类型底泥处理方式研究

Study on Treatment Methods of Different Types of Contaminated Sediments

对于不同污染类型底泥,其处理与处置方式存在差异,为使底泥处理与处置更加高效、合理,应对不同污染类型底泥的处理与处置方式进行分类、分区研究。通过对国内外关于高营养盐、重金属、有机物和复合污染等4类污染底泥的处理技术进行总结和梳理,并对工程中常用的原位覆盖、原位生物修复和异位化学修复技术应用效果和应用条件进行分析,提出了对于污染负荷大、污染物种类复杂的区域可采取底泥环保疏浚技术,并在疏浚后配合生态修复工程,建立强大的生态自净系统,其中疏浚淤泥需及时进行合理、安全的处置,对重金属单一污染淤泥采取"清淤干化+稳定化+资源化利用"处置模式,对有机物单一污染淤泥采取"清淤干化+化学氧化+资源化利用"处置模式,对复合污染淤泥采取"清淤干化+化学氧化+稳定化+资源化利用"处置模式;对于污染程度较轻的区域,可采取生态安全性高的原位控制技术,如原位覆盖技术,并辅以水生植被修复,其中辅助的生态修复工程需综合考虑水生动植物生长的水质、基质和外界条件,使其发挥最佳效果。

There are differences in the treatment and disposal methods for sediments of different pollution types.In order to make the treat⁃ment of sediment more efficient and reasonable,the adopted methods need to be refined.To this end,this paper summarized and sorted out the treatment technologies for the four types of contaminated sediments containing high nutrient salts,heavy metals,organic matter and com⁃posite pollution and analyzed the effectiveness and conditions in engineering application of the three technologies of in⁃situ covering,in⁃situ bioremediation and ectopic chemical restoration,aiming to provide targeted technical guidance for the treatment of different types of contami⁃nated sediments.It is suggested that environmental protection dredging technology should be adopted for areas with large pollution load and complex pollutant types and a strong ecological self⁃purification system should be established after dredging in cooperation with ecological res⁃toration project in which the dredged sludge should be disposed reasonably and safely in time.The disposal mode of“desilting and drying+stabilization+resource utilization”should be adopted for sludge with single heavy metal pollution.The disposal mode of“desilting and drying+chemical oxidation+resource utilization”should be adopted for sludge with single organic pollution.The disposal mode of“desilting and drying+chemical oxidation+stabilization+resource utilization”should be adopted for the compound polluted sludge.On the other hand,for areas with less pollution,in⁃situ control technology with high ecological safety can be adopted,such as in⁃situ covering technology,sup⁃plemented by aquatic vegetation restoration,in which the water quality,substrate and external conditions of aquatic animals and plants shall be comprehensively considered for the auxiliary ecological restoration project to give full play to the best effect.