自然水体中悬浮物对反硝化影响的研究进展

Effects of suspended particles on denitrification in natural water:A review

悬浮物在自然水体(池塘、河流、湖泊等)中普遍存在,相较于上覆水,是微生物更为倾向的附着载体。相较于沉积物,更易获取硝酸盐,是水体反硝化发生的热点微区。悬浮物在水体中经历一系列碰撞、絮凝、溶解、离子交换、吸附解吸等物理化学过程,从而会引起颗粒物粒径、营养盐浓度等发生变化;悬浮物的沉降和再悬浮过程也会引起上覆水和沉积物之间的物质交换,并在好氧缺氧过渡过程中对氮转化造成影响,从而直接或者间接影响水体反硝化速率。本文概括了国内外关于悬浮物影响水体反硝化的研究进展和热点,总结了不同浓度、粒径、组成和种类的悬浮物对反硝化作用的影响,从溶解氧、功能微生物、无机氮、有机碳等环境因素重点归纳了悬浮物影响反硝化的过程,比较和分析了悬浮物反硝化的测定方法。结合当前悬浮物反硝化研究现状,建议未来可以从新兴污染物悬浮物、机理模型、测定方法等方面展开深入研究。

Suspended particles(SPS)are ubiquitous in natural water bodies(ponds,rivers,lakes,etc.)and usually hot spots for denitrification,which tend to adsorb more microorganisms than overlying water and obtain more nitrates than sediments.SPS undergo a series of physical and chemical processes in water bodies,such as collision,flocculation,dissolution,ion exchange,adsorption,and desorption,which would result in changes in particle size and nutrient contents.The sedimentation and resuspension processes of SPS would cause material exchanges between overlying water and sediments,affect nitrogen transformation in the process of aerobic-anoxic transition,and correspondingly affect the denitrification rates of the whole water body directly and/or indirectly.This paper reviews and summarizes(the overseas and domestic)research advances and progresses in SPS effects on water denitrification with focuses on the factors including concentrations,particle sizes,compositions,and types of SPS.The mechanism of SPS to denitrification through different environmental factors,including dissolved oxygen,functional microorganisms,inorganic nitrogen and organic carbon,has been analyzed.The measurement methods of denitrification with SPS have been compared.Based on the current progress of the research,we suggest that future research should extend into the field of understanding of denitrification with SPS through emerging suspended particles of pollutants,mechanism models,and measurement methods.