Biological removal of sulfurous compounds and metals from inorganic wastewaters

Abstract

Sulfur-rich wastewaters that contain relatively little dissolved organic carbon may be generated as a result of several industrial processes: for example, galvanic processes, scrubbing of flue gases at power plants and detoxification of metalcontaminated soils (Table 7.1). However, the mining of heavy metals and coal is, by far and away, responsible for generating the bulk of this type of industrial wastewater (Blowes et al., 2014). Sulfate-and metal-rich effluents produced at the sites of active and derelict mines are frequently referred to as 'acid mine (or rock) drainage' (AMD/ARD). ARD can also be found at sites that have not been impacted by mining, such as gossans in the high Arctic, and upstream of the large and historic mining works at the Rio Tinto, Spain. The pollution of global watercourses due to AMD is immense and occurs in countries that have legacies of historic as well as current mining operations. In the 1990s, it was estimated that there were between 20,000 and 50,000 mines releasing AMD in US Forest Service lands alone (USDA, 1993), impacting many thousands of kilometers of streams and rivers. Flooding of voids left by opencast mining creates 'pit lakes' that have variable chemistries (depending on the ore that was mined, and the local geology) but these are also often acidic and enriched with metals and sulfate (Geller et al., 1998; Sánchez España et al., 2013).

Electro-Fenton beyond the Degradation of Organics: Treatment of Thiosalts in Contaminated Mine Water

“…30,31 However, in real mine water, in which variable concentrations of bivalent metals are expected, the disproportionation of thiosulfate might evolve less H 2 S because of its consumption for metal sulfide precipitation. 32 Gaseous SO 2 may also be formed (eq 8), which may be responsible for the irritating odor. S is resistant to reactions with H 2 O 2 and • OH.…”

“…This observation can be attributed to the rapid disproportionation of S 2 O 3 2– in acidic medium into S (eqs –) and H 2 S (reactions eq ). , However, in real mine water, in which variable concentrations of bivalent metals are expected, the disproportionation of thiosulfate might evolve less H 2 S because of its consumption for metal sulfide precipitation . Gaseous SO 2 may also be formed (eq ), which may be responsible for the irritating odor.…”

Integrated Kinetic Modelling and Microbial Profiling Provide Insights Into Biological Sulfate-Reducing Reactor Design and Operation

“…Sulfate contaminated wastewater streams are generated by numerous industries including coal power generation ( Johnson and Santos, 2000 ), several chemical industries ( Sarti and Zaiat, 2011 ) and mining in the form of acid mine drainage (AMD; Johnson and Hallberg, 2005 ). Biological sulfate reduction (BSR) has been shown to be a sustainable bioremediation option for the treatment of sulfate-rich wastewater streams ( Lens et al, 2002 ).…”

Novel Microorganisms Contribute to Biosulfidogenesis in the Deep Layer of an Acidic Pit Lake

“…It is especially beneficial for remediation of acidic rock drainage systems, which are usually characterized by high metal concentrations. Sulfide reacts with metal cations (e.g., Zn, Co., Cu, Ni and Cd) to form highly insoluble metal sulfides which can then be sequestered or recovered ( Ňancucheo and Johnson, 2012 ; Johnson et al, 2020 ). At pH below 5, biosulfidogenesis can also contribute to acid neutralization through the consumption of protons during processes such as sulfate reduction ( Johnson et al, 2019 ).…”

“…Few sulfide-producing acidophiles have been isolated or otherwise characterized. The bacterial strains isolated to date belong to the phylum Firmicutes and are acid-tolerant rather than truly acidophilic ( Johnson et al, 2020 ) . For example, Thermodesulfobium narugense, isolated from a hot spring in Japan, grows between pH 4 and 6.5 ( Mori et al, 2003 ).…”