Abstract
A variety of multidimensional anthropogenic activities, especially of industrial level, are contaminating our aquatic and terrestrial environments with a variety of metallic and non-metallic pollutants. The metallic and non-metallic pollutants addressed specifically in this review are heavy metals and various compound forms of sulfates, respectively. Direct and indirect deleterious effects of the both types of pollutants to all forms of life are well-known. The treatment of such pollutants is therefore much necessary before their final discharge into the environment. This review summarizes the productive utility of sulfate-reducing bacteria (SRB) for economical and concomitant treatment of the above mentioned wastes. Utilization of agro-industrial wastes and some environmental contaminants including hydrocarbons, as economical growth substrates for SRB, is also suggested and proved efficient in this review. Mechanistically, SRB will utilize sulfates as their terminal electron acceptors during respiration while utilizing agro-industrial and/or hydrocarbon wastes as electron donors/carbon sources and generate H2S. The biogenic H2S will then react vigorously with dissolved metals present in the wastewaters thus forming metal sulfide. The metal sulfide being water insoluble and heavier than water will settle down in the water as precipitates. In this way, three types of pollutants i.e., metals, sulfates and agro-industrial and/or hydrocarbon wastes will be treated simultaneously.
Highlights
No doubt chemical as well as biotechnological industrial units supply us with a number of inevitable products
This review summarizes the productive utility of sulfate-reducing bacteria (SRB) for economical and concomitant treatment of the above mentioned wastes
This review arrives at the conclusion that mixed industrial effluents, loaded with metals and sulfates, can be treated concomitantly using metal-resistant SRB
Summary
No doubt chemical as well as biotechnological industrial units supply us with a number of inevitable products. SRB make morphologically and physiologically a diverse group of obligatory anaerobes which share the ability to dissimilate sulfate to sulfide while oxidizing various growth substrates (Willis et al 1997) These prokaryotic microorganisms are much versatile in their metabolism as well as in the environmental conditions in which they thrive and make their importance in specific ecosystems such as acid mine drainages, cyanobacterial microbial mats, deepsea hydrothermal vents, hypersaline microbial mats, marine and freshwater sediments, methane zone of marine sediments, oil fields’ environments, polluted environments such as anaerobic purification plants, rhizosphere of plants and rice fields (Fauque 1995; Dhillon et al 2003; Rabus et al 2006; Foti et al 2007; Leloup et al 2007; Ollivier et al 2007; Muyzer and Stams 2008; Hussain and Qazi 2016; Wissuwa et al 2016). SRB play an important role in metal sulfide immobilization in anaerobic environments that contain high concentrations of metals (Kaksonen et al 2004; Van Roy et al 2006) This remedy, requires the provision of physical factors and nutrients which can support the growth of relevant microbes as well as production of H2S. While the route 4B illustrates the importance of metal-resistant and heterotrphic sulfidogens for singlechambered bioremediation process development addressing the two categories of the pollutants concurrently
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
