Double-stage membrane-assisted anaerobic digestion process intensification for production and recovery of volatile fatty acids from food waste

• The potential of organic waste streams (i.e., food waste) for the sustainable production of precursor chemicals such as volatile fatty acids (VFAs) using anaerobic digestion (AD) has received significant attention in the present days. AD-derived VFAs have great market appeal if the challenges with their recovery and purification from the complex AD effluent is overcome. In this study, a microfiltration immersed membrane bioreactor (MBR) was used for the production of VFAs from food waste and simultaneously in-situ recovery of VFAs. The MBR set-up was applied for 98 days, with a maximum yield of 0.2 gVFA/gVSadded at an organic loading rate (OLR) of 4 g VS/L/d. The recovered permeate was then subjected to further purification using a side stream ultrafiltration unit. It was found that the removal rates of total solids (TS), total suspended solids (TSS), dissolved solids (DS), volatile solids (VS) and volatile suspended solids (VSS) were above 70–80% in both membranes (10 kDa and 50 kDa), and Phosphorus (P), Total Kjeldahl Nitrogen (TKN), chemical oxygen demand (COD), and NH4+-N were also removed partially. Particularly, VFAs concentration (above 6 g/L) was higher for 10 kDa at pH 5.4 in ultrafiltered solution and permeate flux decline was higher for 10 kDa at pH 5.4. These results are also supported by the measurement of UV–Vis spectra of the solution and visual appearance, providing a promising approach towards building a VFAs-based platform. © 2022 Elsevier B.V.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Industriell bioteknik -- Bioprocessteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Industrial Biotechnology -- Bioprocess Technology (hsv//eng)

Nyckelord

Anaerobic membrane bioreactor

Food waste

Microfiltration

Ultrafiltration

Volatile fatty acids (VFAs)

Anaerobic digestion

Bioconversion

Bioreactors

Chemical oxygen demand

Dissolved oxygen

Effluents

Organic chemicals

Purification

Recovery

Volatile fatty acids

Anaerobic digestion process

Double stage

Organic wastes

Process intensification

Sustainable production

Volatile fatty acid

Volatile solid

Waste stream

ammonia

nitrogen

oxygen

phosphorus

Article

batch fermentation

concentration (parameter)

effluent

fatty acid synthesis

gas chromatography

inoculation

pH

suspended particulate matter

thermal conductivity

ultraviolet spectroscopy

waste component removal

Resource Recovery

Resursåtervinning

Publikations- och innehållstyp

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