| Abstract | The pilot scale Internet of Things (IoT) based wet thermophilic decentralized anaerobic digestion of food waste treatment was developed. Food waste of 10 % Total Solids (TS) was used as the feedstock for the Continuously Stirred Tank Reactor (CSTR) with 675 L working volume. The reactor performance was monitored by employing Internet of Things. The pH, Oxidation Reduction Potential (ORP), and temperature in the reactor were monitored by embedding sensors in the reactor and Programmable Logic Controller (PLC). The quality of the biogas was analyzed by in situ online biogas analyzer. The performance of the reactor was evaluated based on methane yield. Methane concentration was measured through an online biogas monitoring system. The operation and pre-cautionary measures taken were based on the real time data obtained from these novel components provided in the digester.
The performance of the anaerobic digestion process was evaluated by three performance indices viz., biogas yield, methane yield, and Total Solids (TS) and Volatile Solids (VS) reduction in different Organic Loading Rates (OLR) of 0.5, 1.0, 1.5 and 2.0 kg VS/m3.d. The average biogas production from the digester were found to be 187, 231, 302, and 498 L/d at OLR of 0.5, 1.0, 1.5, and 2.0 kg VS/m3.d respectively. The biogas yield values for OLR 0.5, 1.0, 1.5, and 2.0 kg VS/m3.d were 0.55, 0.34, 0.30, and 0.37 m3/kg VS respectively. It was observed that the average methane yield reduced with the increment in organic loading. The methane yield of 0.12, 0.11, 0.06, and 0.03 m3/kg VS were achieved at OLR of 0.5, 1.0, 1.5, and 2.0 kg Vs/m3.d. The lower methane yield was attributed to the accumulation of Volatile Fatty Acids (VFA) evident from lower pH value observed during the experimental period. The TS removal efficiency of OLR 0.5, 1.0, 1.5 and 2.0 kg VS/m3.d was 79.8, 75.2, 68.2 and 72.8 % respectively. The VS removal efficiency were 85.9, 83.6, 79.6 and 82.3 % respectively at OLR of 0.5, 1.0, 1.5 and 2.0 kg VS/m3.d. Moreover, these decentralized community scale anaerobic digestion system with centralized monitoring system through Internet of Things were found suitable for sustainable food waste management in Indonesia.
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