Biostimulation of sulfate-reducing bacteria and metallic ions removal from coal mine-impacted water (MIW) using shrimp shell as treatment agent

Microbial Diversity of Bacteria Involved in Biomineralization Processes in Mine-Impacted Freshwaters

“…In any case, although the composition in microbial species that we observed is representative of a specific moment of the biomineralization process (at the end of the period of Zn reduction), it cannot be excluded that these taxa were not very abundant in the beginning of the experiment. Indeed, many studies reiterate that low abundances of these SRB can sustain high rates of sulfate reduction, when fermentative bacteria such as Clostridium and highly effective syntrophic relationships are present ( Pester et al, 2010 ; Rodrigues et al, 2020 ). In both our samples, a high abundance of Clostridia class was observed and Clostridium sensu stricto species was the only taxa shared between the two inocula.…”

“…In both our samples, a high abundance of Clostridia class was observed and Clostridium sensu stricto species was the only taxa shared between the two inocula. Previous works suggested the Clostridium genus as a SRB because it is strictly linked to the production of H 2 S and to biotreatment processes ( Rodrigues et al, 2020 ). NGS analysis seems to provide new insights into the bacterial taxa involved in the sulfate reduction process as also suggested by results obtained in recent studies using molecular microbiological methods ( Rodrigues et al, 2019 ; Zhou et al, 2020 ).…”

“…Abandoned metal(loid)-sulfide mines are a worldwide environmental concern spreading potentially toxic pollutants through soils, waters, and eventually the whole ecosystem. Mine drainages, in particular acid mine drainages, are commonly characterized by high concentrations of toxic metals and sulfate and represent a risk on involved freshwater ecosystem, causing contamination and chemistry changes of water courses ( De Giudici et al, 2014 , 2018 ; Hwang and Jho, 2018 ; Rodrigues et al, 2020 ). Such waters represent an extreme environment for life but also a unique ecological niche for metabolically active acidophilic bacteria that are well adapted to the multiple environmental stresses encountered.…”

Toxicological Evaluation of Biological and Electrochemical Treatments of Coal Mine-impacted Water (MIW) on Duckweed Landoltia Punctata

“…The biological treatment experiments were built up as performed by Rodrigues et al (2020b) to biostimulate the SRB: microcosms glass flasks (500 mL of capacity) containing 260 mL of MIW together with 2.6 g of shrimp shell (10 g•L −1 ) as a carbon source. In preparation, the shrimp shell waste was washed, dried, and pulverized, as described by Núñez-Gómez et al (2017).…”

“…The sulfate concentrations in coal MIW may range from hundreds to thousands of mg•L -1 (Nariyan et al 2017), and previous studies (Rodrigues et al 2019(Rodrigues et al , 2020b treated it successfully, yielding high removals of sulfate and metallic ions, as well as pH alkalization, by biostimulating sulfate-reducing bacteria (SRB), using shrimp shell waste as substrate. Electrocoagulation (elC) has also been tested, achieving sulfate removal efficiencies of up to 70.95%, as well as pH neutralization (Rodrigues et al 2020a).…”