초록
<P><B>Abstract</B></P> <P>This novel study is focused on estimating the electrohydrolysis pretreatment conditions using DC current (voltage and time) for enhancing the biodegradability of rice straw. The electrohydrolysis pretreatment was performed using graphite electrode with intermittent mode of input voltage fluctuating from 10 to 30 V (voltage study) and in continuous mode for 15–80 min (time study). The result implicated that electrohydrolysis pretreatment with 25 V and 60 min time achieved the maximum solublization (55%). The Batch tests (1 L) were performed to explore the accelerated biomethane production from enhanced solublization and to optimize the food/microorganisms ratio. The different F/M (0.5–3) ratios showed the cumulative methane production ranging from 236 to 319 mL/g-VS<SUB>added</SUB> (control-224.01 mL/g-VS<SUB>added</SUB>). Compositional characterization (FESEM, XRD and FTIR) studies showed the efficacy in disrupting the lignin layer and reducing the cellulose crystallinity of rice straw. The effect of pretreatment on methane production was also kinetically analysed by modified Gompertz, logistic and transference function models.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Electrohydrolysis pretreatment at 25 V improves the degradability of rice straw by enhancing the sCOD and VFA of rice straw by 0.45 and 1.5 times respectively. </LI> <LI> Cumulative methane yield of rice straw was improved by 42.4% (319 mL/g-VS<SUB>added</SUB>) compared to the untreated sample. </LI> <LI> Modified Gompertz models most adequately reproduced the cumulative methane yield data and provided the best fit. </LI> <LI> Net energy gain (+6802.89 kJ) after electrohydrolysis pretreatment was obtained as 17.3 times higher than input energy. </LI> </UL> </P>