RESUMEN
The aim of this study was to evaluate the influence of hydraulic retention time (HRT) on linear alkylbenzene sulfonate (LAS) removal in fluidized bed reactors (FBRs). FBR1 (HRT of 8h) and FBR2 (HRT of 12h) were fed laundry wastewater with 18.6±4.1 to 27.1±5.6mg/L of LAS in the following conditions: ethanol and nitrate addition (Phases I, II and III), nitrate (Phase IV), ethanol (Phase V) and laundry wastewater (Phase VI). LAS removal was 93±12% (FBR1) and 99±2% (FBR2). In FBR1, nitrate influenced significantly on LAS removal (99±3% - Phase IV) compared to the phase without nitrate (90±15% - Phase V). In FBR1 the absence of ethanol was more favourable for LAS removal (99±3% - Phase IV) compared to ethanol addition (87±16% - Phase II). In FBR2, 99±2% LAS removal was found up to 436days. By microbial characterization were identified bacteria as Acinetobacter, Dechloromonas, Pseudomonas and Zoogloea.
Asunto(s)
Reactores Biológicos , Tensoactivos/química , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Ácidos Alcanesulfónicos/química , Ácidos Alcanesulfónicos/aislamiento & purificación , Ácidos Alcanesulfónicos/metabolismo , Bacterias/metabolismo , Biodegradación Ambiental , Reactores Biológicos/microbiología , Ecotoxicología/métodos , Diseño de Equipo , Consorcios Microbianos/genética , Consorcios Microbianos/fisiología , Nitrógeno/metabolismo , Tensoactivos/aislamiento & purificación , Tensoactivos/metabolismo , Eliminación de Residuos Líquidos/instrumentación , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación , Contaminantes Químicos del Agua/metabolismoRESUMEN
The efficiency of linear alkylbenzene sulfonate (LAS) removal from laundry wastewater and the related microbial community was investigated in an anaerobic fluidized bed reactor (AFBR). The AFBR was operated in three stages, in addition to the biomass adaptation stage without LAS (stage I). The stages were differentiated by their supplementary co-substrates: stage II had sucrose plus ethanol, stage III had only ethanol, and stage IV had no co-substrate. The replacement of sucrose plus ethanol with ethanol only for the substrate composition favored the efficiency of LAS removal, which remained high after the co-substrate was removed (stage II: 52 %; stage III: 73 %; stage IV: 77 %). A transition in the microbial community from Comamonadaceae to Rhodocyclaceae in conjunction with the co-substrate variation was observed using ion sequencing analysis. The microbial community that developed in response to an ethanol-only co-substrate improved LAS degradation more than the community that developed in response to a mixture of sucrose and ethanol, suggesting that ethanol is a better option for enriching an LAS-degrading microbial community.
Asunto(s)
Bacterias/metabolismo , Etanol/metabolismo , Consorcios Microbianos/fisiología , Sacarosa/metabolismo , Tensoactivos/metabolismo , Contaminantes Químicos del Agua/metabolismo , Ácidos Alcanesulfónicos/aislamiento & purificación , Ácidos Alcanesulfónicos/metabolismo , Aniones , Bacterias/clasificación , Bacterias/aislamiento & purificación , Biodegradación Ambiental , Reactores Biológicos/microbiología , Especificidad de la Especie , Tensoactivos/aislamiento & purificación , Microbiología del Agua , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodosRESUMEN
A conceptual and integrated analysis of the UASB/Polishing Pond system is presented in relation to the removal of specific constituents not normally covered in the pond's literature, namely surfactants (linear alkylbenzene sulphonate, LAS), micropollutants (phthalates and bisphenol A) and sulfide. Experimental studies carried out on a small full-scale UASB/PP system have shown limited overall removal efficiencies for some constituents (53% to 70% for phthalates and 50% for LAS), but excellent removal levels for bisphenol A (around 99%) and sulfide (no trace concentrations were detected in the second and third ponds of the series). Further research is needed to investigate possible limitations and to identify means to improve the performance of the UASB/PP system.