养猪废水厌氧储存过程中的氮素转化特征

Nitrogen Transformation Characteristics During Anaerobic Storage of Swine Wastewater

研究废水储存过程中氮的转化,可为废水再利用提供科学依据。本研究旨在探讨养猪废水(SWW)贮存过程中氮的转化及其机理。在SWW贮藏过程中,随贮藏时间的延长,SWW中总有机碳(TOC)、总氮(TN)和氨氮(NH_(4)-N)含量显著降低,硝态氮(NO_(3)-N)和亚硝态氮(NO_(2)-N)含量保持在较低水平。可溶性有机氮(SON)含量显著增加。贮藏180天后,原水总氮损失36.1%,NH_(4)-N含量减少727.6mg/L,SON含量增加202.6mg/L,表明贮藏过程中发生了大量的氮损失和NH_(4)-N向SON的显著转化。在不同贮藏时间,反硝化和谷氨酸/谷氨酰胺合成的基因丰度最高,异相硝酸盐还原、天冬酰胺合成和厌氧氨氧化的基因丰度中等。反硝化和氨同化基因的高活性(如氨基酸和酰胺的合成)表明SWW贮藏过程中氮转化活跃。

Investigation of nitrogen(N)transformation during wastewater storage can lay scientific foundation for wastewater reuse.This study aimed to investigate N transformation and the related mechanisms during swine wastewater(SWW)storage.During SWW storage,the contents of TOC,TN and NH_(4)-N in SWW decreased significantly with the storage time,while the contents of NO_(3)-N and NO_(2)-N kept very low.However,the contents of dissolved organic nitrogen(SON)increased significantly.After 180 days of storage,the total nitrogen of the raw SWW lost by 36.1%,NH_(4)-N content of 727.6 mg/L was transformed,and SON content of the stored SWW increased by 202.6 mg/L,indicating that substantial nitrogen loss and significant nitrogen conversion from NH_(4)-N to SON occurred during the storage process.In addition,the gene abundances of denitrification and glutamate/glutamine synthesis were the highest,and the gene abundance of dissimilatory nitrate reduction,asparagine synthesis and anaerobic ammonia oxidation were medium at the different storage time.The high activity of denitrification and ammonia assimilation genes(e.g.,the synthesis of amino acids and amides)indicated active nitrogen conversion during SWW storage.