Potential production of struvite from the anaerobic digestion of food waste: analysis in one-phase and two-phase configurations

Brayan Alexis Parra-Orobio,Andrea Pérez-Vidal,Patricia Torres-Lozada

doi:10.2166/wst.2021.299

Brayan Alexis Parra-Orobio, Andrea Pérez-Vidal + Show 1 more

Open Access

https://doi.org/10.2166/wst.2021.299

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Abstract

Abstract Anaerobic digestion (AD) of food waste (FW) has been gaining more interest as it has potential for the production of organic amendments with high struvite (NH4MgPO4·6H2O) content, which is a nutrient of great interest in sustainable agriculture. In this study, the influence of AD of FW in one- and two-phase configurations on methane production and the potential for struvite formation using digestate was evaluated. It was found that the two-phase is more efficient as its organic loading rate is 18% higher than that of one-phase configuration. In addition, the two-phase yielded a higher methane content in biogas (&gt;60%) and a higher organic matter transformation in each of the AD stages (&gt;20%); further, the digestate complied with the regulatory requirements for the use of organic amendments, thereby being deemed as a Type-B material with a struvite precipitation potential, exceeding 80%, as opposed to the digestate from one-phase configuration, which may represent a revenue of up to US$ 26,505 per year.

Highlights

In Latin America, municipal solid waste (MSW) is commonly managed through disposal (36% in sanitary landfills, 33% in uncontrolled open dump sites, and 25% in controlled open dump sites), which costs US$10–$20 per ton of MSW (Rojas & Flórez 2019)
In anaerobic digestion (AD), biodegradable organic matter is transformed into biogas, which has economic value as a source for renewable energy and as a biomass mixture component; biodegradable organic matter has large agricultural potential owing to its biofertilizing power (Ma et al 2018)
The stability in the two-phase reactor is due to the fact that the phase separation allows the consolidation of microbial consortia that facilitate the degradation of complex and heterogeneous organic matter, such as food waste (FW), and that, in turn, is observed in the quantity and quality of the biogas generated using this type of configuration

Summary

Introduction

In Latin America, municipal solid waste (MSW) is commonly managed through disposal (36% in sanitary landfills, 33% in uncontrolled open dump sites, and 25% in controlled open dump sites), which costs US$10–$20 per ton of MSW (Rojas & Flórez 2019). These landfills and dump sites often lack adequate techniques for the management and treatment of leachates, which are one of the main sources of greenhouse gases (Margallo et al 2019). In AD, biodegradable organic matter is transformed into biogas (mostly methane), which has economic value as a source for renewable energy and as a biomass mixture component (a digested material or digestate, which is the source of organic fertilizers); biodegradable organic matter has large agricultural potential owing to its biofertilizing power (Ma et al 2018)

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