Sulfide-driven nitrous oxide recovery during the mixotrophic denitrification process  

作　　者：Cong Yu Sen Qiao Jiti Zhou 

机构地区：[1]Key Laboratory of Industrial Ecology and Environmental Engineering(Ministry of Education,China),School of Environmental Science and Technology,Dalian University of Technology,Dalian 116024,China

出　　处：《Journal of Environmental Sciences》2023年第3期443-452,共10页环境科学学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No. 51878111);the National Key Research and Development Project (No. 2019YFA0705804);the Natural Science Foundation of Jiangsu Province (No. BK20181224);the Liaoning Revitalization Talents Program (No. XLYC1807067)。

摘　　要：We propose a novel sulfide-driven process to recover N_(2)O during the traditional denitrification process.The optimum initial sulfide concentration was 120 mg/L,and the N_(2)O percentage in the gaseous products (N_(2)O+N_(2)) was up to 82.9%.Moreover,sulfide involved in denitrification processes could substitute for organic carbon as an electron donor,e.g.,1g sulfide was equivalent to 0.5-2 g COD when sulfide was oxidized to sulfur and sulfate.The accumulation of N_(2)O was mainly due to the inhibiting effect of sulfide on nitrous oxide reductase (N_(2)OR),which was induced by the supply insufficiency of electrons from cytochrome c (cyt c) to N_(2)OR.When the initial sulfide concentration was 120 mg/L,the N_(2)OR activity was only 36.8%of its original level.According to the results of cyclic voltammetry,circular dichroism spectra and fluorescence spectra,significant changes in the conformations and protein structures of cyt c were caused by sulfide,and cyt c completely lost its electron transport capacity.This study provides a new concept for N_(2)O recovery driven by sulfide in the denitrification process.In addition,the findings regarding the mechanism of the inhibition of N_(2)OR activity have important implications both for reducing emissions of N_(2)O and recovering N_(2)O in the sulfide-driven denitrification process.

关 键 词：N_(2)O recovery N_(2)OR inhibition Cytochrome c Electron transfer capacity 

分 类 号：X701[环境科学与工程—环境工程]