Application of biomagnetic nanoparticles for biostimulation of biogas production from wastewater treatment

This study presents biomagnetic nanoparticles (BMNPs) as a biostimulant for wastewater treatment and biogas upgrading to natural quality (>90% CH4). Notwithstanding, application of anaerobic digestion (AD) in wastewater settings is still limited with slow kinetics and low methanation yield. Here, four BMNPs (CuO, Fe2O3, TiO2, Cu/Fe-TiO2) were investigated to enhance the high-rate anaerobic system for complete degradation of organic waste to value-added products (water and biogas). Sugar refinery wastewater was used as a substrate and activated sludge as inoculum. This was carried out in 800 mL working volume bioreactors at a mesophilic temperature of 35 degrees C and hydraulic retention time of 30 days. Results showed the substrate-inoculum degradation in the control system, when induced with the BMNPs increased the methane (CH4) potential from 63% to 100%. Likewise over 75% water index of chemical oxygen demand, total suspended solids, and volatile solids were removed. Stimulatingly, the biogas production and wastewater treatability was significantly improved upon adding the BMNPs to the bioreactors which enriched the methanogenic activities. The post-sludge analysis showed the morphological and elemental distribution of the BMNPs, and their biomagnetic interactions with the micobes which enhanced the adsorptive removal of the contaminants and the biogas production yield. The Gompertz modified kinetic model significantly (P < 0.05) favoured the cumulative biogas yield obtained for all the bioreactors with a kinetic rate constant within the range of 0.182504-0.203027 d-1. The performance of Cu/Fe-TiO2 additives superseded the rest of the BMNPs. In conclusion, BMNPs revealed economic prospects of regeneration and reuse with external magnets for effective wastewater treatment. (c) 2021 Elsevier Ltd. All rights reserved. Second International Conference on Aspects of Materials Science and Engineering (ICAMSE 2021). This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).