Biosurfactant induced microwave disintegration of macroalgae for fermentative biohydrogen production

Abstract

Biosurfactant-induced microwave disintegration (BSMD), an energy and cost effective pretreatment method, has been proposed to increase biohydrogen production from marine macroalgae (Chaetomorpha antennina). Microwave disintegration (MD) was performed for microwave powers from 90 to 540 Watts in varied periods from 0 to 60 mins. During this MD process, a disintegration time of 25 mins and microwave power of 360 W were obtained as optimum conditions, resulting in the dissolvable organics release (DOR) of 1860 mg/L and a disintegration efficiency (DE) of 14.3%. BSMD was implemented by adding the biosurfactant dosages from 0.005 to 0.05 g/g TS with the optimum power of MD at various intervals of time of 0–30 min. The optimum biosurfactant dosage for efficient disintegration in BSMD was 0.03 g/g TS, resulting in 19.55% DE and 2542 mg/L of DOR in 10 mins. BSMD sample showed increased volatile fatty acid (VFA) production of about 1393 mg/L than MD (1000 mg/L). In addition, BSMD consumed less input energy (IE) of (480 kWh / kg of solids) than MD (1200kWh / kg of solids). The highest amount of biohydrogen was produced by BSMD (120 mL H2/g COD) than MD (78 mL H2/g COD). The results showed BSMD method was energy-efficient for producing biohydrogen with an energy ratio of 1.96, and economical with a net profit of 74.78 $.