Abstract

CASTRO RIVERA, Rigoberto; SOLIS OBA, María Myrna; CHICATTO GASPERIN, Vanesa  and  SOLIS OBA, Aída. BIOGAS PRODUCTION THROUGH CO-DIGESTION OF CATTLE WASTE AND AGRICULTURAL RESIDUES OF TOMATO CULTIVATION ( Solanum lycopersicum L.). Rev. Int. Contam. Ambient [online]. 2020, vol.36, n.3, pp.529-539.  Epub May 04, 2021. ISSN 0188-4999.  https://doi.org/10.20937/rica.53545.

Anaerobic digestion is an alternative to reduce pollution problems due to the open sky disposal of waste, such as manures and agricultural residues; besides, it is an option for the generation of alternative energies due to biogas production. The aim of this work was to evaluate the co-digestion of cattle waste with tomato crop residues. The experimental design was completely randomized under a 2 × 2 factorial arrangement, considering two levels of manure (20 and 50 %) and two pH initial levels (6.8 and 7.5). It was found that by adjusting the pH to 7.5 using 20 or 50 % manure, the total production of biogas and methane increased 100 %, compared to that obtained in digesters starting at pH 6.8. In digesters where 50 % of manure and 50 % of tomato crop residues were used, the methane content reached 45 %, which is the minimum to be used as combustible. The use of 20 % manure and 80% tomato crop residues produced 35 to 37 % methane. The 50:50 proportion manure:tomato residues best treatment was in with pH adjust at 7.5 . The resulting digestate did not present phytotoxicity in the test with lettuce seeds, and its coliform and salmonella was below those indicated in standard NOM 004-SEMARNAT.

Keywords : alternative energies; methane; digestate.