水库热分层期沉积物中有机物特性及对好氧反硝化细菌脱氮的影响

Characteristics of Organic Matter in Sediments During the Thermal Stratification of a Reservoir and Effects on an Aerobic Denitrifier

本研究以水源水库热分层期沉积物中有机物为研究对象,在分析其相对分子质量分布和有机物荧光特性的基础上,探究了沉积物中有机物为碳源时,好氧反硝化细菌的脱氮效能、细菌生长及碳去除性能.结果表明:(1)水源水库在热分层期,沉积物中相对分子质量>100×10^3的有机物所占比例较高;同时相比于不同月有机物的相对分子质量分布,7月时沉积物中相对分子质量大的有机物所占的比例最低(44.62%),显示出较小的相对分子质量;(2)水源水库沉积物中有机物由陆地类腐殖质组分C1(250 nm,425 nm)、类色氨酸和氨基酸物质C2(230 nm/280 nm,322 nm)和传统微生物类腐殖质混合物C3(250 nm,340 nm)所组成,其中色氨酸和氨基酸类的物质(组分C2)所占比例较高,同时在7月时显示出较大的总荧光强度;(3)好氧反硝化过程中,5月有机物显示出较好的作为电子供体的特征,而7月的有机物却表现出较好的作为能源物质的性能,同时使得好氧反硝化细菌WGX-9显示出较高的氮去除特性;(4)相比于天然有机物、藻类有机物和实际水源水库水,沉积物中有机物作为碳源时可以较好地促进菌株WGX-9的好氧反硝化脱氮效能.本文阐明了水源水库热分层期沉积物中有机物特性及对好氧反硝化细菌的影响,将为微污染水体氮污染控制工程提供依据.

In this study,the relative molecular weight distribution and fluorescent characteristics of the organic matter in sediments during the thermal stratification of a drinking water reservoir were studied.The nitrogen removal,growth performance,and carbon removal ability of an aerobic denitrifier were investigated when the organic matter in sediments was used as a carbon source.The results found that:(1)during the stratification period in the drinking water reservoir,the organic matter in sediments has a larger proportion of relative molecular mass>100×10^3.It can be observed that compared with the relative molecular weight distribution in different months,the percentage of macromolecular organic matter in sediments is the lowest in July(44.62%),showing a characteristic of smaller relative molecular weight;(2)the organic matter in sediments of the drinking water reservoir was composed of terrestrial humic-like substance component C1(250 nm,425 nm),tryptophan and amino acid-like substances component C2(230 nm/280 nm,322 nm),and traditional microbial humic-like substances component C3(250 nm,340 nm).Component C2 accounted for a higher percentage,and the organic matter in July showed a higher total fluorescence intensity;(3)during the aerobic denitrification process,organic matter in May displayed better characteristics as an electron donor,while organic matter in July exhibited excellent performance as an energy substance and better denitrification characteristics of the strain WGX-9;(4)the aerobic denitrification performance of the strain WGX-9 can be significantly promoted when the organic matter in sediments is a carbon source,compared with natural organic matter,algae organic matter,and actual water of the drinking water reservoir.This study clarifies the characteristics of the organic matter in sediments during the thermal stratification period of the drinking water reservoir and its effect on an aerobic denitrifier.This will provide a scientific basis for the research of nitrogen pollution control in micro-polluted water sources.