Sludge samples from dual-layers elemental sulfur packed denitrification reactors

In this study, an S0 autotrophic denitrification reactor (SADR) and a wood-chunks and S0 mixotrophic denitrification reactor (WSMDR) with dual-layers were constructed. The lower layer filled with S0 or a combination of wood-chunks and S0, while the upper layer only filled with inert material. Nitrate contaminated wastewater were pumped to the reactors from the bottom of each layer. In this way, the intermediate products from SAD and WSMD acted as electron donors for denitrification in the upper layers, achieving effective nitrate removal and low by-products generations. The objectives of this study were to: 1) investigate denitrification performance in both reactors at different operation conditions, including flow rate and IC; 2) evaluate final sulfate and sulfide generation in the effluent during operation; and 3) perform metagenomic analysis to reveal the difference in microbial community structures between different reactors or layers, followed by clarifying the mechanism of the decreasing in by-products .

本研究构建了双层结构的单质硫自养反硝化反应器（S0 autotrophic denitrification reactor, SADR）与木屑-单质硫混合营养反硝化反应器（wood-chunks and S0 mixotrophic denitrification reactor, WSMDR）。下层分别填充单质硫（S0）或木屑与单质硫的混合物，上层仅填充惰性材料。将硝酸盐污染废水从各反应器的底部泵入，使得单质硫自养反硝化（SAD）与混合营养反硝化（WSMD）产生的中间产物可作为上层反硝化过程的电子供体，从而实现高效硝酸盐去除与低副产物生成。本研究的目标如下：1）探究两种反应器在包括流速与无机碳（Inorganic Carbon）在内的不同运行条件下的反硝化性能；2）评估运行过程中出水的最终硫酸盐与硫化物生成情况；3）开展宏基因组分析以揭示不同反应器及不同层间的微生物群落结构差异，并阐明副产物生成量降低的机制。