Characterization of four digestates from different types of substrates used in biogas production in Northern Peru

Abstract

Background Biol is one of the best-known digestates, which occurs during anaerobic digestion in biodigesters to generate biogas, using animal manure and vegetable waste. This digestate type is used in organic agriculture due to its easy application, contributing simultaneously to the circular economy and food security. Methods The objective of this study was to characterize four types of biol, generated in four anaerobic biodigesters for biogas production implemented in northern Peru fed with manure: i) pig manure; ii) cattle manure; iii) horse manure; iv) cattle manure with coffee processing water. All the biodigesters implemented had the same design but worked under different environmental conditions. Descriptive and multivalent statistics were applied to the data obtained for the parameters evaluated. Results The biols obtained had different nutritional compositions, depending on the type of substrate used. The biol from pig manure was characterized by high concentrations of bacteria, the one from cattle manure had low concentrations of nutrients in general, the one from horse manure was rich in salts, and the one from cattle manure with coffee processing water was rich in organic matter. Conclusions These results showed that all the biols obtained can be used for organic agriculture. However, their selection will depend on the nutritional requirements of the type of crop and soil where the biols are to be applied.