Cultivation of granules containing anaerobic decolorization and aerobic degradation cultures for the complete mineralization of azo dyes in wastewater

Granules which could efficiently mineralize azo dyes were cultivated through immobilization of aerobic degradation strains in a core composed of anaerobic decolorization cultures. The core was obtained in a UASB reactor incubated with anaerobic decolorization bacteria. Aerobic degradation strains were then grown on the surface of the anaerobic core in a SBR. Three of the granules’ surface layers demonstrated the occurrence of immobilization. The granulation process was monitored with 16S rDNA high throughput sequencing. Anaerobic decolorization cultures belonging to the genera of unclassified, Levilinea, and Petrimonas and the aerobic degradation genera of Thauera, unclassified, Thermomonas, and Ottowia were successfully fixed in the granules. The obtained granules were capable of decolorizing azo dyes, and the generated aromatic amines were then completely mineralized in aerated environment. When azo dye wastewater was treated with the granules, the removal efficiency of COD and TOC was not restricted by loading concentrations.

通过将好氧降解菌株固定于由厌氧脱色培养物构成的核心层中，成功培养出可高效矿化偶氮染料的颗粒污泥。该核心层通过在接种厌氧脱色菌的UASB反应器（升流式厌氧污泥床反应器，Upflow Anaerobic Sludge Blanket Reactor）中培养获得。随后将好氧降解菌株接种至SBR反应器（序批式活性污泥反应器，Sequencing Batch Reactor）内的厌氧核心层表面进行定植培养。其中三个颗粒污泥的表层均证实存在固定化现象。研究采用16S rDNA高通量测序技术对颗粒化过程进行监测分析。隶属于未分类菌属、Levilinea属以及Petrimonas属的厌氧脱色培养物，以及隶属于Thauera属、未分类菌属、Thermomonas属以及Ottowia属的好氧降解菌属均成功固定于该颗粒污泥内。所制备的颗粒污泥可实现偶氮染料的脱色降解，且其生成的芳香胺类物质可在曝气环境中被完全矿化。采用该颗粒污泥处理偶氮染料废水时，COD（化学需氧量，Chemical Oxygen Demand）与TOC（总有机碳，Total Organic Carbon）的去除效率不受进水负荷浓度的限制。