Using Digestate Compost as a Substrate for Anaerobic Digestion

Abstract

Anaerobic digestion (AD) of separately collected biowaste is an ecologically and economically interesting waste treatment technology due to the production of utilizable biogas and coeval reduction of waste mass fractions. The combination of AD with subsequent composting leads to a higher degree of overall biowaste carbon utilization compared to single composting. Compost may also be of interest for an anew digestion step, since carbon, e.g., of lignocellulose, is made available by the aerobic composting process. The possibility to redigest liquid digestate and/or digestate compost was evaluated using batch reactors. It could be shown that compost is an interesting substrate for AD that might be used for stabilization of the digestion process, e.g., in times of deteriorating reactor performance due to changes in quantity and quality of the feed material.

Proposal of Thermoactinomyces mirandus sp. nov., a filamentous, anaerobic bacterium isolated from a biogas plant

“…Strain AMNI-1 T was isolated from a biogas plant located in Roppen (Tyrol, Austria, 47.230 N 10.833 E) in 2015. The anaerobic digestion plant represents a 750.000-L plug-flow digester that is operated under thermophilic conditions and designed to treat separately gathered organic fractions of household wastes ( Wagner et al 2018 ). For a description of running parameters and physical–chemical properties of the reactor please refer to ( Illmer et al 2009 ).…”

Biological Pretreatment Strategies for Second-Generation Lignocellulosic Resources to Enhance Biogas Production

“…Papinagsorn et al [59] successfully tested ensiled napier grass in combination with chemical pretreatment for co-digestion with cow dung yielding up to 8.34 kJ•g −1 VS. Vervaeren et al [60] investigated maize silage additives for enhanced biogas production and could verify up to a 14.7% increase in biogas production for certain additives. Wagner et al [61] used composting as a treatment strategy to enhance methane production from digestate and showed a positive impact of composting with increased biogas and methane yields in a subsequent anaerobic digestion process.…”

Effects of biological pre-treatment of lignocellulosic waste with white-rot fungi on the stimulation of 14C-phenanthrene catabolism in soils

“…However, biological pre-treatment methods have some advantages over other pretreatment methods, such as mechanical methods which are costly due to high energy input and the formation of toxic inhibitory products such as acetic, furural and phenolic acids, as well as high solvent cost associated with chemical pre-treatment strategy (Ramarajan and Manohar, 2017). Therefore, the biological pre-treatment processes are more economically viable, superior and eco-friendly compared to the other pre-treatment techniques (Isroi et al, 2011;Wagner et al, 2018). Biological pre-treatment processes represent promising approaches to the removal of lignin from the waste materials, while increasing enzymatic hydrolysis of the hemicellulosic and cellulosic contents to monomeric sugars such as xylose, arabinose, mannose, glucose and galactose, the readily metabolizable carbon source for microbial growth and metabolism.…”