Bioleaching of multiple heavy metals from contaminated sediment by mesophile consortium

Abstract

A defined mesophile consortium including Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirilum ferriphilum was applied in bioleaching sediments contaminated with multiple heavy metals. Flask experiments showed that sulfur favored the acidification in the early stage while pyrite led to a great acidification potential in the later stage. An equal sulfur/pyrite ratio got the best acidification effect. Substrate utilization started with sulfur in the early stage, and then the pH decline and the community shift give rise to the utilization of pyrite. Solubilization efficiency of Zn, Cu, Mn, and Cd reached 96.1, 93.3, 92.13, and 87.65%, respectively. Bioleaching efficiency of other elements (As, Hg, Pb) was not more than 30%. Heavy metal solubilization was highly negatively correlated with pH variation. Logistic models were well fitted with the solubilization efficiency, which can be used to predict the bioleaching process. The dominant species in the early stage of bioleaching were A. ferrooxidans and A. thiooxidans, and the abundance of L. ferriphilum increased together with pyrite utilization and pH decline.

The influence of aluminum chloride on biosynthetic schwertmannite and Cu(ii)/Cr(vi) adsorption

“…Heavy metals pose a signicant threat to the environment and public health because of their acute toxicity, non-biodegradable nature and tendency for bioaccumulation. [1][2][3] They are usually discharged into the natural environment due to anthropogenic activities without sufficient treatment. Among the toxic heavy metals, Cu(II) and Cr(VI) are considered as two prioritised pollutants.…”

Explore the recycling of bioleaching functional bacteria and sulfur substrate using the sulfur-covered biochar particles

“…Heavy metal bioleaching curves were fitted using logistic equations [22]: (see Equation 1 in the We assumed that when M = 95%M limit , the bioleaching is finished. Then based on equation 1, T 95% could be calculated using equation 2: (see Equation 2 in the Supplementary Files)…”

Comparative Analysis of Attachment to Chalcopyrite of Three Mesophilic Iron and/or Sulfur-Oxidizing Acidophiles

“…However, because of various requirements (high temperature, complicated pretreatment) and formation of passivating layers (elemental sulfur, copper-rich polysulfide, or iron sulfate-type precipitates), it is recalcitrant to be leached via hydrometallurgical processing [1][2][3][4][5]. Among hydrometallurgical methods, bioleaching turned out to be the best alternative [6][7][8]. The dissolution of metal ions from insoluble metal sulfides by microorganisms is known as bioleaching [9].…”