Влияние коэффициента рециркуляции эффлюента метантенка на выход биоводорода в двухстадийном процессе анаэробной биоконверсии жидких органических отходов

This paper considers the production of biohydrogen in a two-stage process of anaerobic bioconversion of organic matter (OM) of liquid waste with recirculation of digester effluent into an anaerobic bioreactor for dark fermentation (ARDF). The values of the average biohydrogen specific yield (BSY) and the average volumetric biohydrogen production rate (VBPR) were obtained at 4 recirculation ratios (RR) of the digester effluent (1, 1.1, 1.18, 1.25) and 2 hydraulic retention times (HRT) ( 1 and 2.5) in ARDF. Organic loading rate (olr) varied from 7.96 to 21.6 g OM / (l ∙ day). The pH value in ARDF practically did not depend on RR and HRT, and ranged from 3.8 to 4.16. The maximum BSY was 0.108 l / (day ∙ g OMin) with a RR of 1.11 and a HRT of 2.5 days. The maximum VBPR was observed at RR 1 and HRT 1 day and amounted to 1.67 l / (l ∙ day). The methane content in biohydrogen-containing biogas at modes providing maximum BSY and VBPR was no more than 0.01%, but it increased sharply at higher values of RR and HRT. The hydrogen content in biogas averaged 50-52% for all combinations of RR and HRT, but it sharply decreased to 46.7% with HRT 2.5 and RR 1.25. In general, with RR 1.11 and HRT 1 day, an increase in BSY by 9.05% was observed, while the VBPR decreased by 1.04% (compared with RR 1.0 and HRT 1 day). In general, the experi- mental data obtained allow us to speak of a RR equal to 1.11 as the most effective for both HRTs in the studied range of RR.