Abstract
In the present study a biorefinery system is proposed using catering and agro industrial waste for biogas and low phytotoxic digestate. Anaerobic co-digestion of catering waste with partially pretreated (microwave 800 J/g/min + steam 121 °C 40 min) maize crop residues was conducted under different composition (20-50%) of feedstock. The results showed that the biogas production was increased by 2.03 times in co-digestion experiment (40 % partially pretreated maize crop residue + 60 % catering waste: TCM3) as compared to catering waste alone (control). The increment in accumulative methane 116.7 m3 t-1 was recorded in TCM3 which is due to improvement in biodegradation under co-digestion process. The post digestion byproduct (residual digestate) was evaluated for its phytotoxicity which is supplied with aerobic post treatment. Thethe post treatment has improved the digestate quality by decreasing VS/TS ratio from 259 g/L to 173 g/L and slightly increase the pH from 7.29 to 8.32. Seed germination assay showed that the germination percentage (G %), germination index (GI) and vigor index (VI) were relatively higher with post treated digesate as compared to un-treated digestate. In the germination test using wheat seeds, the post treated digestate (5 % sol. extract) achieved higher values of GI and VI (46 and 609) whereas in un-treated,values for these indices were 14 and 62 respectively. Overall the findings of the present study identify the significance of co-digestion based waste biorefinery, in order to develop value added bio-products such as biogas and biofertilizers.
Highlights
The advancement in living standard has risen the generation of organic waste at substantial rates
The results regarding organic matter removal efficiency (VS content basis) and change in Chemical oxygen demand (COD) are explained as under: The results regarding VS content and organic matter removal efficiency are described in Figure 1 which showed that the co-digestion experiments with pre-treated maize crop residues showed more reduction in VS as compared to untreated maize crop residues
The improved COD degradation with pre-treated maize crop residue was due to the fact that pretreatment provides more organics in solubilized form and more available to anaerobic bacteria (Anjum et al, 2018). These results showed that use of pre-treated crop residues is more promising with catering waste co-digestion where optimum mixing ration was found at 40% maize crop residue with 60% catering waste and labeled as TCM3
Summary
The advancement in living standard has risen the generation of organic waste at substantial rates. One of the signific sources of organic wastes in municipalities is from catering services which are generated excessively in hotels, canteens, restaurants, and the aviation industry (Ayomoh et al, 2008; Jiang et al, 2018). Catering wastes are problematic to treat due their high moisture content, it can involve in the transmission of pathogen microorganisms that possibly cause diseases in humans and pollute drinking water (Chen et al, 2017). It requires being dealt in an environmentally safe method (Zhang et al, 2005; Izumi et al, 2010; Anjum et al, 2016).
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call