Methanogenic activity inhibition by increasing the linear alkylbenzene sulfonate (LAS) concentration

Abstract

The effect of the initial concentration of linear alkylbenzene sulfonate (LAS) on specific methanogenic activity (SMA) was investigated in this work. Six anaerobic flasks reactors with 1 L of total volume were inoculated with anaerobic sludge (2 g VSS L(-1)). The reactors were assayed for 42 days, and fed with volatile fatty acids, nutrients, and LAS. The initial LAS concentrations were 0, 10, 30, 50, 75, and 100 mg L(-1) for the treatment flasks T1 (control), T2, T3, T4, T5, and T6, respectively. When compared with T1, T2 exhibited a 30% reduction in maximum SMA and total methane production (TMP). In treatment T3 through T6, the reductions were 44-97% (T3-T6) for SMA, and 30-90% (T3-T6) for TMP. Total LAS removal increased following the increase in the initial LAS concentration (from 36% at T1 to 76% at T6), primarily due to the high degree of sludge adsorption. LAS biodegradation also occurred (32% in all treatments), although this was most likely associated with the formation of non-methane intermediates. Greater removal by adsorption was observed in long-chain homologues, when compared to short-chain homologues (C13 > C10), whereas the opposite occurred for biodegradation (C10 > C13). The C13 homologue was adsorbed to a great extent (in mass) in T4, T5 and T6, and may also have inhibited methane formation in these treatments.

Reator de leito fluidificado em escala aumentada para tratamento de água residuária de lavanderia comercial em co-digestão com esgoto doméstico: otimização das condições operacionais e caracterização taxonômica e funcional dos microrganismos do biofilme

“…relataram que a presença de LAS afetou a Na presença de etanol foi observado remoção menor que 80% apenas em R5'; ou seja, de 73% para 66,9 mgLAS L -1 (Tabela 6.10).A diminuição na remoção de matéria orgânica na presença de LAS em experimentos em batelada é comumente relatada Duarte et al (2010). observaram que 22 mgLAS L -1 resultaram em redução na remoção de DQO de 74±19% para 44±14% empregando Reator Anaeróbio Operado em Bateladas Sequenciais (ASBR) Souza et al (2016). observaram que a conversão de matéria orgânica foi fortemente inibida pelo aumento da concentração inicial de…”