Pelleting is a successful method to eliminate the presence of Clostridium spp. from the digestate of biogas plants. (October 2015)

• Record Type: Journal Article
• Authors: Pulvirenti, Andrea; Ronga, Domenico; Zaghi, Massimo; Tomasselli, Anna Rita; Mannella, Lorenzo; Pecchioni, Nicola
• Is Part Of: Biomass and bioenergy. Volume 81(2015:Oct.)
• Page Start: 479
• Page End: 482
• Publication Date: 2015-10
• Subjects: Clostridium spp. -- Biogas -- Digestate -- Pellet -- Parmigiano Reggiano -- Dairy farming; Biomass energy -- Periodicals; Biomass -- Periodicals; Energy-Generating Resources -- Periodicals; Bioénergie -- Périodiques; 333.9539
• DOI: 10.1016/j.biombioe.2015.08.008
• Languages: English
• ISSNs: 0961-9534

Abstract

Abstract: Biogas production is increasing as a sustainable energy supply, with digestate resulting as a by-product of biogas plants. As a result, the high concentration of Clostridium spp. in digestate became a concern in dairy farming areas. Clostridium spores can contaminate soils and crops when digestate is used as fertilizer, causing a conflictual cohabitation of biogas with traditional cheese productions. In order to solve the problem, this study aimed to search for a technical solution enabling either a drastic reduction or the elimination of the content of Clostridium spp. within digestate. Results showed a complete elimination of Clostridium spp. in pelleted stored solid digestate; in addition, pelleting caused a reduction of pH and water mass fraction in terms of fresh weight, and a concentration of mineral nutrients compared to stored solid digestate. Pellet can represent a possible sustainable solution both in reducing potential risks linked to the presence of Clostridium spp. in digestate and in improving the transportation and distribution of high-value fertilizer. Hence, pelleting of solid digestate could offer a simple and efficient method to allow cohesistence of biogas plants and dairy farming. Highlights: Pelleting eliminate the presence of Clostridium spp. in solid digestate. Mineral nutrients are more concentrated in pellet solid digestate. Pelleted solid digestate is an alternative, sustainable and safe fertilizer.