Predominance of syntrophic bacteria, Methanosaeta and Methanoculleus in a two-stage up-flow anaerobic sludge blanket reactor treating coffee processing wastewater at high organic loading rate

Abstract

The effect of the organic loading rate (OLR) on the performance and microbial composition of a two-stage UASB system treating coffee processing wastewater was assessed. The system was operated with OLR up to 18.2 g COD (L d) and effluent recirculation. Methane production and effluent characteristics were monitored. The microbial composition was examined through next-generation sequencing and qPCR from the anaerobic sludge of the first reactor (R1) operated at low and high OLR. The system showed operational stability, obtaining a maximum methane production of 2.2 L CH (L d), with a removal efficiency of COD and phenolic compounds of 84 and 73%, respectively. The performance of R1 at high OLR in steady conditions was associated with an appropriate proportion of nutrients (particularly Fe) and a marked increase of the syntrophic bacteria Syntrophus and Candidatus Cloacimonas, and acetoclastic and hydrogenotrophic methanogens, mainly Methanosaeta, Methanoculleus, Methanobacterium and Methanomassiliicoccus.

Hydrolysis and Methanogenesis in UASB-AnMBR Treating Municipal Wastewater Under Psychrophilic Conditions: Importance of Reactor Configuration and Inoculum

“…Syntrophus spp. produce H 2 through fermentation of organic compounds, being capable of maintaining syntrophic interactions with hydrogenotrophic methanogens (Botello Suárez et al, 2018). However, methanogens and SRB are hydrogen and acetate consuming organisms which contribute to the syntrophic relationship as consumers.…”

Caracterización fisicoquímica y microbiológica de aguas mieles del beneficio del café

“…Adicionalmente, se resalta que las dos muestras de agua residual deben ser sometidas a procesos de tratamiento previo a su disposición en cuerpos de agua o directamente sobre el suelo, debido a que pueden afectar las especies animales y vegetales existentes en cuerpos hídricos y/o afectar procesos productivos, como es el caso de germinación de semillas, crecimiento de plantas, entre otras. Algunas alternativas que se emplean actualmente para este fin son: coagulación con extractos provenientes de semillas de Moringa oleífera [36], coagulación -floculación química y procesos de oxidación [37], oxidación enzimática [17], biometanización [38,39], aireación y filtración con especies vegetales [40,41], entre otros. Es importante definir la viabilidad técnica y económica de estas alternativas de acuerdo con las características de las zonas productivas y los volúmenes de aguas mieles producidos, así como nuevas alternativas de aprovechamiento para este residuo agroindustrial, en el marco del concepto de biorrefinería.…”

Performance of an anaerobic biofilm reactor through the application of different operational conditions

“…Other outstanding works using high load reactors are: Doloman et al (2017), evaluated the changes in the composition of the microorganisms presents in the anaerobic co-digestion of biomass of microalgae cultivated in municipal wastewater. They used two UASB reactors and the operating time of the reactors was 87 days with an OLR between 0.9 and 5.4 gCOD/L.d; Arreola-Vargas et al (2018), estimated the performance of a Packed Bed Reactor (PBR) with a capacity of 445 L, in the anaerobic digestion process of tequila vinasse applying different OLRs for 231 days; Botello-Suárez et al (2018), studied the effects of increasing the OLR (6.1 to 18.2 gCOD/L.d) of coffee vinasse on the yield and microbial composition in two-stage 20 and 10 L UASB reactors. The system operated for 306 days under mesophilic conditions.…”