Enhancing the Fertilizer Quality and Remediation Ability of Anaerobic Digestate via Myrothecium verrucaria Treatment

Abstract

Low fertilizer quality and remediation ability are considered the major factors hampering the land application of anaerobic digestate. Therefore, the role of Myrothecium verrucaria treatment in enhancing the fertilizer quality and remediation ability of digestate for land application was explored. Higher content of humic acid (7.5 g/L) with a higher degree of humification index and oxygen-containing functional groups was observed in the digestate receiving Myrothecium verrucaria treatment. Likewise, humic acid formed from Myrothecium verrucaria treatment had a higher capacity of heavy metal binding. Moreover, the viable and culturable count of S. faecalis, S. typhi, C. perfringens, and E. coli pathogens in the digestate decreased to approximately 12.50%, 41.70%, 18.87%, and 50.00% and 25.97%, 64.44%, 37.51%, and 75.27%, respectively, after treatment with Myrothecium verrucaria. This study provided a novel strategy to enhance the fertilizer quality, remediation ability, and biological safety of anaerobic digestate for land application.