Produção de biogás a partir da digestão anaeróbia de águas residuárias: uma revisão sistematizada e bibliométrica

Abstract

The increase in the temperature of the planet as a result of the greenhouse effect accelerated after the Industrial Revolution due to the increase in the emission of greenhouse gases (GHGs) by human activity, increasing the frequency of changes in climate and environmental disasters across the globe. Technologies for waste management and bioenergy recovery can contribute to the reduction of GHG emitted into the atmosphere, by supporting the transition to a circular economy. Within this context, an assessment of the development of primary global research on the production of biogas (biomethane) from anaerobic digestion (AD) of wastewater was proposed through a bibliometric analysis of articles published from 1995 to 2022, obtained in an advanced search on the Web of Science platform, reaching a total of 5,430 articles that studied the production of biogas through the wastewater AD in the last 27 years, with the year 2022 having the highest number of publications (557 articles). For the analysis of keywords, a high frequency of use of “wastewater treatment” (377 occurrences) and “sewage sludge” (155 occurrences) was observed in contrast to “energy recovery” (82 occurrences), demonstrating a focus of work, still directed more towards the wastewaters treatment than towards the production of biogas. Elsevier stood out as a publisher, publishing at least 50% of the analyzed articles. Regarding the countries that produced the most studies, China leads with 21% of the publications and among the institutions in which the authors are affiliated, the Chinese Academy of Sciences stood out (232 articles). The authors Bing-Jie Ni from the University of Technology Sydney and Zhiguo Yuan from the University of Queensland stood out both as the ones who published the most and as the most cited, while in the ninth position among those who published the most appeared the researcher Marcelo Zaiat from Brazil. As for the keywords related to wastewater, “wastewater from olive processing” (72 occurrences) stood out, waste that has been seen as a very serious environmental problem due to its high chemical demand for oxygen in the process of stabilization of the organic matter and toxicity. Among the most relevant articles, the main mathematical models for simulating the systems, operating parameters, composition of the medium (wastewater, inoculum, among others), pre-treatment of substrates and performance improvement technologies studied were evaluated, knowing some of the main advances and challenges of biogas production from wastewater AD.