Production of soluble organic compounds and assessment of the effect on anaerobic digestion

Scopus of LIFECAB project (LIFE16 ENV/IT/000179) is the extraction of SBO (Soluble Organic Biostimulants) from compost and the assessment of the effect of these biological compounds on the anaerobic digestion process at ACEA site. In the perspective of circular economy, the SBO are renewable high-added value compounds that can be used to produce myriads of products, among which surfactants, detergents, emulsifiers and even fertizers and bio-stimulants. The SBO, mainly composed by humic and fulvic acids, can be obtained by compost by means of a hydrolytic route. High solubilisation yield is reached when the initial solution is high pH (14) and when high temperatures are used (90°C). After the SBOs production using a prototype specifically designed for this purpose, ACEA has tested SBOs in a 2500 m3 bio-reactor, adding the SBO at 0.04 % in the feeding slurry. The other bio-reactor (totally comparable with the first one) has been employed as the control test. The first feedback from the SBO utilization on the industrial scale of ACEA anaerobic digestion plant is very significant: the reduction of ammonia and the increase in methane production. New experimental campaigns will be carried out at ACEA site, in order to validate the preliminary results, testing different SBO feeding concentrations and the feeding modes.