Enhancing biomethane production from food waste using olive pomace hydrochar: An optimization study

Abstract

The effect of olive pomace hydrochar (OPHC) on food waste (FW) anaerobic digestion (AD) was investigated experimentally at five concentrations (5.85, 10, 20, 30, and 34.11 g/L). The selective concentrations are based on an experimental approach that was utilized to study the effect of adding 10-30 g/L OPHC to the AD of FW. The highest experimental methane yield (YCH4) and biodegradability are obtained for 10 and 20 g/L of OPHC, with 33 and 82 % improvement, respectively. Response surface methodology (RSM) was used to assess the impact of independent factors, including hydraulic retention time (HRT) and olive pomace hydrochar (OPHC) added, on YCH4. The R2 of 0.9073 and 0.9485 are obtained for YCH4 using face-centered and circumscribed designs, respectively, due to the model's accuracy. The optimal YCH4 was 428.81 ml/g VS with an OPHC added of 20 g/L and an HRT of 20 days.

Keywords

• Food waste
• Olive pomace hydrochar
• Anaerobic digestion
• Methane yield
• Optimization