Advanced search
Start date

Microbial characterization of anaerobic fluidized bed reactor involved in the nonionic surfactant alcohol ethoxylate non-branched (GENAPOL) degradation

Full text
Fabricio Motteran
Total Authors: 1
Document type: Doctoral Thesis
Press: São Carlos.
Institution: Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD)
Defense date:
Examining board members:
Maria Bernadete Amâncio Varesche Silva; Márcia Helena Rissato Zamariolli Damianovic; Erich Kellner; André Luiz Meleiro Porto; Flávio Henrique da Silva
Advisor: Maria Bernadete Amâncio Varesche Silva

The aim of this study was to evaluate the removal of nonionic alcohol ethoxylate non-branched (AE) in anaerobic fluidized bed reactor filled with sand as support material, on a bench scale (1.2 L) with 18 hours of TDH, recirculation and continuous flow. The reactor was inoculated with sludge from a UASB reactor used in the treatment of swine manure and fed with synthetic substrate plus nonionic GENAPOL® C-100 (Sigma-Aldrich®) as a source of AE. Monitoring analysis of the nonionic surfactant AE concentration and organic matter, as well as the physicochemical parameters were performed to observe and quantify the reactor stability, in the removal and degradation of the surfactant. The reactor operation was divided into five phases: inoculation (535±121 mg/L of COD), biomass adaptation (600±70 mg/L of COD), Phase I (4,7 mg/L of AE and 623±65 mg/L of COD), Phase II (22,5 mg/L of AE and 735±87 mg/L of COD), Phase III (51,4 mg/L of AE and 697±68 mg/L of COD), Phase IV (107,4 mg/L of AE and 845±87 mg/L of COD) and Phase V (97,9 mg/L of AE and 882±126 mg/L of COD). Application of the techniques PCR/DGGE and pyrosequencing of the 16S rRNA region were performed to observe the microbial diversity in the operational phases IV and V. The average removal efficiency of organic matter and AE was 88% and 99%, respectively, during the reactor operation. The populations similarity of the Archaea and Bacteria Domains were 74% and 59%, respectively, for samples from Phase IV (with sucrose) and Phase V (without sucrose). Sucrose did not alter the physical-chemical behavior of the fluidized bed reactor, but this co-substrate influenced both in the volatile fatty acids production, as in the diversity of microorganisms involved in the AE degradation. Through the pyrosequencing analysis of samples from Phases IV and V of the reactor (support material and phase separator), 83 genera were identified of which 18 were related to the nonionic surfactant degradation, as well as its byproducts. Highest relative abundance values were obtained for the following genera: Sporomusa, Geobacter, Desulfobulbus, Synergistes, Sedimentibacter, Holophaga, Serpens and Azonexus. A high phylogenetic diversity and similarity to sequences of bacteria related to the degradation of nonionic AE surfactant were observed. (AU)