A sulfate reducing bioreactor controlled by an electrochemical system enables near-zero chemical treatment of metallurgical wastewater.

Metallurgical wastewaters are characterized by a low pH (<4), high concentrations of sulfate (15 gSO L), and metal(loid)s. Current treatment requires the consumption of chemicals such as alkali and high levels of waste sludge generation. In this study, we have shown that combining water electrolysis and sulfate reducing bioreactors enables the in-situ generation of base and H, eliminating the need for base and electron donor addition, resulting in the near-zero treatment of metallurgical wastewater.

Selective leaching of copper and zinc from primary ores and secondary mineral residues using biogenic ammonia.

With the number of easily accessible ores depleting, alternate primary and secondary sources are required to meet the increasing demand of economically important metals. Whilst highly abundant, these materials are of lower grade with respect to traditional ores, thus highly selective and sustainable metal extraction technologies are needed to reduce processing costs. Here, we investigated the metal leaching potential of biogenic ammonia produced by a ureolytic strain of Lysinibacillus sphaericus on eight primary and secondary materials, comprised of mining and metallurgical residues, sludges and automotive shredder residues (ASR).

Effect of speciation and composition on the kinetics and precipitation of arsenic sulfide from industrial metallurgical wastewater.

Precipitation of arsenic as AsS produces little waste sludge, has the potential for low chemical consumption and for selective metal(loid) removal. In this study, arsenic removal from acidic (pH 2), metallurgical wastewater was tested in industrially relevant conditions. Sulfides added at a S:As molar ratio of 2.