Martins, RamiroBoaventura, RuiPaulista, Larissa Oliveira2018-03-132018-03-132017Martins, Ramiro; Boaventura, Rui; Larissa, Paulista (2017). Anaerobic digestion performance in the energy recovery of kiwi residues. In IOP Conference Series: Earth and Environmental Science. Prague: IOP Publishing Ltd. ISSN 1755-1301755-1307http://hdl.handle.net/10198/16280World production and trade of fruits generate losses in the harvest, post-harvest, handling, distribution and consumption phases, corresponding to 6.8% of total production. These residues present high potential as a substrate for the anaerobic digestion process and biogas generation. Thus, the energy valuation of the agro-industrial residues of kiwi production was evaluated by anaerobic digestion, aiming at optimizing the biogas production and its quality. Ten assays were carried out in a batch reactor (500 mL) under mesophilic conditions and varying a number of operational factors: different substrate/inoculum ratios; four distinct values for C: N ratio; inoculum from different digesters; and inoculum collected at different times of the year. The following parameters were used to control and monitor the process: pH, alkalinity, volatile fatty acids (VFA), volatile solids (VS) and chemical oxygen demand (COD). Among the tests performed, the best result obtained for the biogas production corresponded to the use of 2 g of substrate and 98 mL of inoculum of the anaerobic digester of the Wastewater Treatment Plant (WWTP) of Bragança, with addition of 150 mg of bicarbonate leading to a production of 1628 L biogas.kg-1 VS (57% methane). In relation to the biogas quality, the best result was obtained with 20 g of substrate and 380 mL of inoculum from the anaerobic digester sludge of WWTP of Ave (with addition 600 mg of sodium bicarbonate), presenting a value of 85% of CH4, with a production of 464 L biogas.kg-1 VS.engAnaerobic digestionEnergy recoveryKiwi residuesconference paper10.1088/1755-1315/95/4/042044