title: Enhanced methane production from rice straw co-digested with anaerobic sludge from pulp and paper mill treatment process.
abstract: Rice straw is a widely available lignocellulosic waste with potential for energy recovery through anaerobic digestion. Lignin slows the hydrolysis phase, resulting in low methane recovery and long digestion periods. Although pretreatment is effective, it often requires high energy inputs or chemicals that are not feasible for farm-scale systems. This study investigates a unique co-digestion strategy to improve methane yields and reduce digestion times for farm-scale systems. By adding both piggery wastewater and paper mill sludge, specific methane yields in laboratory-scale digesters reached the theoretical value for rice straw (i.e. 330LNCH4/kgVS) over the 92-day period. Accelerated hydrolysis of the straw was directly related to the quantity of sludge added. The most stable digester, with sufficient buffering capacity and nutrients, contained equal parts of straw, wastewater and sludge. This approach is feasible for farm-scale applications since it requires no additional energy inputs or changes to existing infrastructure for dry systems.
authors.affiliation: University of Cassino, via Di Biasio 43, 03043 Cassino, Italy. Electronic address: wendy.mussoline@unicas.it.
authors.forename: Wendy
authors.initials: W
authors.lastname: Mussoline
authors.forename: Giovanni
authors.initials: G
authors.lastname: Esposito
authors.forename: Piet
authors.initials: P
authors.lastname: Lens
authors.forename: Alessandro
authors.initials: A
authors.lastname: Spagni
authors.forename: Andrea
authors.initials: A
authors.lastname: Giordano
mesh_terms: D000468:Alkalies / Q000032:analysis; D000641:Ammonia / Q000032:analysis; D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D001709:Biotechnology / Q000379:methods*; D005232:Fatty Acids, Volatile / Q000096:biosynthesis; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D008697:Methane / Q000096:biosynthesis*; D009584:Nitrogen / Q000032:analysis; D012275:Oryza / Q000737:chemistry*; D010209:Paper; D012722:Sewage / Q000737:chemistry*; D013997:Time Factors; D014131:Trace Elements / Q000032:analysis; D062065:Wastewater / Q000737:chemistry*
chemical_list: D000468:Alkalies; D000641:Ammonia; D005232:Fatty Acids, Volatile; D007220:Industrial Waste; D008697:Methane; D009584:Nitrogen; D012722:Sewage; D014131:Trace Elements; D062065:Wastewater
keywords: Anaerobic; Co-digestion; Energy recovery; Lignocellulosic; Paper mill