Volatile Fatty Acids Production by Acidogenic Fermentation of Wastewater: A Bibliometric Analysis

Abstract

This study presents a bibliometric analysis of the scientific literature on volatile fatty acids (VFA) production from wastewater fermentation published from 1981 to 21 June 2021. A total of 618 papers obtained from the Scopus database were analyzed using VOSviewer 1.6.16 software. According to the results, this topic has been capturing the attention of researchers over the years, but with different research approaches, including optimization of anaerobic digestion in two-stage reactors, biological removal of nutrients from wastewater, energy production in bioelectrochemical systems, and recovery of VFA as value-added intermediate products to be used as inputs in a variety of industries. In addition, the bibliometric networks obtained from the authors’ keyword frequency showed that wastewater treatment by using fermentation to obtain VFA as a value-added by-product is an emerging topic that undoubtedly requires further research and collaboration between scientific institutions. In this regard, different types of wastewater have been used as a substrate for acidogenic fermentation; however, and based on the results, the production of VFA from cassava processing wastewater is seen as one of the emerging issues of this field. Finally, evaluating the effect of operating conditions on the fermentation process, such as pH, hydraulic retention time, organic loading rate, temperature, inoculum and substrate concentration, independent of the final application of the VFA produced, is a relevant aspect for bioprocess optimization and implementation on a large scale.