Waste valorization in winery and distillery industry by producing biofertilizers and organic amendments

Abstract

The winery and distilling spirits industry generate a remarkable amount of by-products and wasted, that are not properly managed, posing socioeconomic problems and environmental risks, due to its seasonal and polluting characteristics. Traditionally, valorization strategies have focused on composting. for direct use as a soil organic amendment.  However, this process requires a long period and a large free surface (aerobic), generating an effluent (leachate) and could cause phytotoxicity and an antimicrobial effect. An alternative treatment strategy for these organic wasted is anaerobic digestion, which period less than 25 days and in a reduced work area, two digestates are obtained (liquid and solid), suitable for agricultural use. This work aims at evaluating the feasibility of using winemaking lees and distillation vinasses, together with composting leachate in the obtaining of biofertilizers and organic amendments by anaerobic digestion using a microbial consortium and estimating their economic valorization for a winery in Peru. The evolution of the digestion process (pH, Electrical Conductivity and Temperature) was monitored, and then to characterize the digestates with a physicochemical and microbiological analysis. The results of both products obtained show a significant concentration of organic matter, phytonutrients (nitrogen, phosphorus, potassium, etc.) and humic substances in a slightly acidic medium (pH value of between 3.8 and 5), due to the presence of some lactic acid bacteria and Bacillus species, which could confer properties as biostimulators and biocontrol agents. Their stability (pH, color and odor) was evaluated for an additional 30 days, showing excellent hygienic conditions, due to the absence of pathogenic microorganisms, could make it possible to incorporate them together with others agricultural inputs during the viticultural season. Therefore, the valorization of winemaking and wasted by-products by producing biofertilizers and organic amendments for agricultural use could largely replace the use of synthetic fertilization and recover soil fertility. The socioeconomic and environmental benefits would be multiple, within an agroecological transition and circular economy approach.