Wheat straw pretreatment with KOH for enhancing biomethane production and fertilizer value in anaerobic digestion

Wheat straw biodegradability during anaerobic digestion was improved by treatment with potassium hydroxide（KOH）to decrease digestion time and enhance biomethane production and fertility value.KOH concentrations of1%（K1）,3%（K2）,6%（K3）and 9%（K4）were tested for wheat straw pretreatment at ambient temperature with a C:N ratio of 25:1.86% of total solids（TS）,89% of volatile solids（VS）and 22% of lignocellulose,cellulose and hemicellulose（LCH）（22%）were decomposed effectively with the wheat straw pretreated by 6% KOH.Enhanced biogas production and cumulative biomethane yield of 258 ml·（g VS）-1were obtained increased by 45% and 41%respectively,compared with untreated wheat straw.Pretreated wheat straw digestion also yielded a digestate with higher fertilizer values potassium（138%）,calcium（22%）and magnesium（16%）.These results show that TS,VS and LCH can be effectively removed from wheat straw pretreated with KOH,improving biodegradability biomethane production and fertilizer value.