Hydrogen bioproduction with anaerobic bacteria consortium from brewery wastewater

Abstract

Biohydrogen production is a cheap and clean way to obtain hydrogen gas. In subtropical countries such as Brazil the average temperatures of 27 C can favor the hydrogen producing bacteria growth. A mixed culture was obtained from a subtropical sludge treating brewery wastewater and anaerobic batch reactors were fed with glucose, sucrose, fructose and xylose in low concentrations (2.0, 5.0 and 10.0 g L À1) at 37 C, initial pH 5.5 and headspace with N 2 (99%) to maintain the anaerobic conditions. The inoculum was a subtropical granulated sludge from UASB (Upflow Anaerobic Sludge Blanket) reactor treating brewery wastewater. The higher H 2 yields were obtained in reactors operated with 2 and 5 g L À1 of fructose and they were 1.5 mol H 2 mol À1 of fructose and 1.3 mol H 2 mol À1 of sucrose, respectively. The volatile fatty acids (VFA) generated at the end of operation were, predominantly, butyric and acetic acid, indicating the favoring of the metabolic route of hydrogen generation by the consortium of anaerobic bacteria from the brewery wastewater. Biomolecular analyses revealed the predominance of hydrogen producing bacteria from Firmicutes phylum distributed in the families Streptococcaceae, Veillonellaceae and uncultured bacteria. These results confirm future applications of subtropical sludges with agroindustrial wastewaters containing low concentrations of sugars on hydrogen generation.

Aplicação de resíduo da agroindústria citrícola para a produção de hidrogênio utilizando culturas puras e mistas

“…Os coeficientes de determinação (R 2 ), obtidos pelo tratamento estatístico [(1) 1,0 e (2) 0,998], reforçaram que o modelo adotado representou os dados obtidos experimentalmente, nos reatores anaeróbios em batelada alimentados com glicose. Mais uma vez a rota metabólica de geração de hidrogênio foi favorecida nos reatores operados com culturas puras de Clostridium (inóculos 1 e 2) que são espécies produtoras de H 2 a partir de açúcares [20], principalmente glicose [10] e inativada para os reatores operados com o consórcio citrícola, com a geração expressiva de etanol. No ensaio 2, com água residuária citrícola como fonte de carbono, os inóculos (1), (2) apresentaram crescimento da biomassa microbiana reduzida (Figura 4).…”

“…possui potencial elevado de produção de gás hidrogênio e solventes como etanol e butanol, além de serem microrganismos eficientes na degradação de carboidratos simples e complexos, resistentes a substâncias tóxicas, escassez de nutrientes e valores de pH abaixo de 6 [25 -28]. PACHIEGA et al [20] obteve geração de hidrogênio em reatores anaeróbios alimentados separadamente com glicose, frutose, sacarose e xilose com consórcio de bactérias anaeróbias de lodo granular, tratando resíduos de cervejaria, identificado nos gêneros Clostriduim sp., Veillonella sp., Streptococcus sp. e inferiu que tais microrganismos estavam envolvidos nos processos fermentativos de geração de H 2 , como no presente estudo.…”

Updates on biogas enrichment and purification methods: A review

“…The substrates for anaerobic digestion can originate from agriculture and agroindustry, [31][32][33][34] livestock, [35][36][37] lignocellulosic residues, [38][39][40] and urban waste. [41][42][43] The energy potential varies according to the raw material and the processing technology used.…”

Brewery Effluent Treatment with Conventional and Natural Coagulants

“…Typically, brewery wastewater treatment has aerobic, anaerobic and combined treatment technologies. In addition, many different methods such as nanofiltration [4], quenched plasma [13], activated sludge process, aerated lagoon, Trickling filter process, Bifiltration towers [12], upflow anaerobic sludge blanket (UASB) [12], [14][15][16][17] have been studied. Membrane technology [14], electrochemical method [17], anaerobic fluidized bed reactors [14], Microbial fuel cell [18] and reverse osmosis [19] have been tested.…”