Abstract:
Heavy metal pollution is a serious concern of the modern era due to its widespread negative
effects on human health and to the environment. Conventional technologies applied for the uptake
of this category of persistent pollutants are complex, often expensive, and inefficient at low metal
concentrations. In the last few years, non-conventional alternatives have been studied in search of
better solutions in terms of costs and sustainability. Microbial adsorbents are one of the biomass-based
sorbents that have extensively demonstrated excellent heavy metals removal capacity even at low
concentrations. However, most of the carried-out research regarding their application in wastewater
treatment has been performed in discontinuous systems. The use of microorganisms for the uptake
of metal ions in continuous systems could be an important step for the upscale of the remediation
processes since it facilitates a faster remediation of higher quantities of wastewaters loaded with
heavy metals, in comparison with batch systems removal. Thus, the current research aims to analyze
the available studies focusing on the removal of metal ions from wastewaters using microorganisms,
in continuous systems, with a focus on obtained performances, optimized experimental conditions,
and the sustainability of the bioremoval process. The present work found that microbial-based
remediation processes have demonstrated very good performances in continuous systems. Further
sustainability analyses are required in order to apply the bioremediation technology in an optimized
environmentally friendly way in large-scale facilities.
