Performance and microbial characterization of the two stage process with upflow anaerobic sludge blanket reactors (UASB) treating swine wastewater / Desempenho e caracterização microbiana do processo de dois estágios com reatores anaeróbios de fluxo ascendente com manta de lodo (UASB) tratando águas residuárias de suinocultura

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

Two bench scale UASB reactors (volumes of 39,0 and 10,5 L) were operated in sequence, fed with swine wastewater with total suspended solids (TSS) concentration around 5000 mg/L in the first reactor, with controlled temperature (from 25 to 30 Celsius degrees) and operating with hydraulic detention time (HDT) in the first reactor varying from 62 to 16 h and in the second reactor from 16 to 4 h. The objective was to evaluate the performance and to characterize physically and microbiologically the sludge from UASB reactors operated in two stages treating swine wastewater. The results obtained in phase 1, with HDT of 62 h in the first reactor and TSS in the influent of 5240 mg/L, presented total COD removal efficiencies of 86% and 59% and TSS reduction efficiency of 82% and 57%, in the first and second reactors, respectively. The removal efficiency of total COD and TSS in the system, in phase 1, was 95% and 94%, respectively. In the phase 2, using HDT of 31 h in the first reactor and TSS of 5000 mg/L in the influent, it was observed a total COD removal efficiency of 86% and 43% and TSS reduction efficiency of 85% and 58%, in the first and second reactors, respectively. The system removal efficiency of total COD and TSS in phase 2, was 92% and 94%, respectively. In phase 3, with a HDT of 16 h in the first reactor and TSS of 5490 mg/L in the influent, it was observed a total COD removal efficiency of 73% and 23% and TSS reduction efficiency of 65% and 20%, in the first and second reactors, respectively. The total COD removal efficiency and TSS reduction efficiency in the system, in phase 3, was 79% and 73%, respectively. The volumetric organic loading rate (VOLR) applied in the first reactor, in phase 1, was 4,55 kg total COD/M POT.3.d, in phase 2 was 8,75 kg total COD/M POT.3.d and in phase 3 was 18,65 kg total COD/M POT.3.d. The CH IND.4production in the first reactor was from 17,50 to 68,20 L CH IND.4/d and in the second reactor from 1,62 to 5,50 L CH IND.4/d decreasing the HDT in the experiment phases. The UASB reactor installed in sequence were efficient in the dissolved fraction removal and, mainly, to the fraction due to the TSS influent concentration. The total VOL value of 4,55 kg COD/M POT.3.d was measured in the first reactor, it was achieved TSS and total COD removal efficiencies above 90% and dissolved COD above 85%. For the OVL of 18,65 kg COD/M POT.3.d in the first reactor the TSS and total COD removal were above 70% and dissolved COD above 75%. The larger methane specific production was obtained with a total VOL of 2,55 kg COD/M POT.3.d in the second reactor and 8.65 kg COD/M POT.3.d in the first reactor. The UASB reactors operation with the TSS concentration values of 5000 mg/L in the influent was prejudicing the sludge granulation process. The granules present a microbial morphology disperse distribution that doesnt characterize a layers defined distribution. The predominant metonogenic archeas were similar to Methanosaeta.

ASSUNTO(S)

two stage anaerobic reactor methanogenic arqueas arqueas metanogênicas anaerobic digestion reatores anaeróbios de dois estágios digestão anaeróbia swine wastewater resíduos de suínos

ACESSO AO ARTIGO

Documentos Relacionados