利用生活污水提升厌氧-生物电化学耦合系统处理染料废水的效能及关键功能微生物研究

Domestic sewage enhancing azo dye wastewater treatment in anaerobic digestion-bioelectrochemical system and functional microbial community analysis

构建了厌氧生物处理过程与生物电化学过程耦合(AD-BES)的废水处理系统,以生活污水为碳源,研究了AD-BES系统对偶氮染料橙黄II的强化去除效果,分析并优化了AD-BES反应器降解橙黄II染料的关键影响因素,包括生活污水所占比例、电解质Na_2SO_4的浓度等因子.结果表明,生活污水作为廉价碳源能够有效提升橙黄II的脱色效率.在8 h降解时间内,生活污水所占比例为1时的脱色效率比生活污水所占比例为1/3时提升了35.8%.进一步研究发现,通过添加电解质Na_2SO_4能够继续提高橙黄II的脱色效率,在0～0.025 mol·L^(-1) Na_2SO_4范围内,随着Na_2SO_4浓度的提高,脱色效率持续升高,通过优化,在0.025 mol·L^(-1)时反应4 h后脱色率达到90.1%,7 h后达到98%,对COD的去除量达到159 mg·L^(-1).通过对碳纤维电极进行扫描电镜(SEM)测试和电极上的生物膜高通量基因测序,发现在微电流刺激下碳纤维电极上快速富集了相对丰度较大的功能菌群,主要包括具有胞外电子传递能力的Proteobacteria(变形菌门)和降解复杂碳源能力的Bacteroidetes(拟杆菌门)中的功能菌属.

Azo dye reductive dechlorination was studied in a constructed anaerobic digestion-bioelectrochemical system(AD-BES) when applying domestic sewage as an efficient electron donor. The key operation factors that influenced Orange II reduction efficiencies were investigated and were optimized in AD-BES, including the proportion of domestic sewage and concentration of Na2SO4 as electrolyte. Results show that decolorization efficiency of Orange II increased along with the increase of domestic sewage proportion. Decolorization rate was increased by 35.8% when sewage inoculation ratio improved to 1 compared with that of 1/3 at 8 h. Using Na2SO4 as electrolyte can improve the reduction efficiency and the higher efficiency was achieved when the concentration of Na2SO4 was increased among 0~0.025 mol·L-1. Under the optimized Na2SO4 concentration of 0.025 mol·L-1, the decolorization efficiency reached to 90.1% at 4 h, and increased to the maximum of 98% along with COD removal of 159 mg·L-1 at 7 h. Scanning electron microscopic observation results show a great deal of microorganisms attached on the carbon fiber. Bacteroidetes and Proteobacteria played important parts in Orange II reduction and extracellular electron transfer.