Methodological Approaches to Optimising Anaerobic Digestion of Water Hyacinth for Energy Efficiency in South Africa

Abstract

Anaerobic digestion has been identified as a feasible fragment of a bioeconomy, yet numerous factors hinder the adoption of the technology in South Africa. Apart from its energy recovery, other nonmarket advantages support the technology. Though it may be challenging to have a price tag, they provide clear added worth for such investments. With a growing energy demand and global energy transitions, there is a need to sustainably commercialise the biogas industry in South Africa. Most studies are at laboratory scale and under specific conditions, which invariably create gaps in using their data for commercialising the biogas technology. The key to recognising these gaps depends on knowing the crucial technical phases that have the utmost outcome on the economics of biogas production. This study is a meta-analysis of the optimisation of anaerobic digestion through methodological approaches aimed at enhancing the production of biogas. This review, therefore, argues that regulating the fundamental operational parameters, understanding the microbial community’s interactions, and modelling the anaerobic processes are vital indicators for improving the process stability and methane yield for the commercialisation of the technology. It further argues that South Africa can exploit water hyacinth as a substrate for a self-sufficient biogas production system in a bid to mitigate the invasive alien plants.

Pathways for the Valorization of Animal and Human Waste to Biofuels, Sustainable Materials and Value-Added Chemicals

“…The use of a single feedstock has been reported to be problematic because of several challenges such as poor biogas yield, limited year-round feedstock availability and digester instability [118]. To some extent, these challenges can be overcome through different methods, such as pH adjustment [119], manipulation of the digestion time [120], intermittent feeding [121], multistage AD processes [122], the introduction of external microorganisms and co-digestion [123]. Among these options, co-digestion of more than one feedstock has been reported to be very successful in overcoming the challenges associated with mono-feedstock digestion.…”

Pathways for the Valorization of Animal and Human Waste to Biofuels, Sustainable Materials, and Value-Added Chemicals

“…The use of a single feedstock has been reported to be problematic because of several challenges, such as poor biogas yield, limited year-round feedstock availability, and digester instability [92]. To some extent, these challenges can be overcome through different methods, such as pH adjustment [93], manipulation of the digestion time [94], intermittent feeding [95], multistage AD processes [96], the introduction of external microorganisms, and co-digestion [97]. Among these options, co-digestion of more than one feedstock has been reported to be very successful in overcoming the challenges associated with mono-feedstock digestion.…”

The Multifaceted Function of Water Hyacinth in Maintaining Environmental Sustainability and the Underlying Mechanisms: A Mini Review

“…Thus, the microbiome changed along with the alternations of these parameters during AD [ 133 , 134 ]. To further enhance sustainability, WH is often co-digested with other plant biomass, animal dung and other wastes [ 135 , 136 ]. The co-digestion could increase biofuel yield, most likely because the mixed substance contains nutrients at a more suitable C/N ratio and consequentially provides a more suitable pH and temperature, thereby favoring the growth of microbial consortiums [ 135 , 137 ].…”