Abstract
Heavy metal pollution is one of the most serious environmental problems, due to metal ions persistence, bioavailability, and toxicity. There are many conventional physical and chemical techniques traditionally used for environmental clean-up. Due to several drawbacks regarding these methods, the use of living organisms, or bioremediation, is becoming more prevalent. Biotechnological application of microorganisms is already successfully implemented and is in constant development, with many microbial strains successfully removing heavy metals. This paper provides an overview of the main heavy metal characteristics and describes the interactions with microorganisms. Key heavy metal resistance mechanisms in microorganisms are described, as well as the main principles and types of heavy metal bioremediation methods, with details on successful pilot scale bioreactor studies. Special attention should be given to indigenous bacteria isolated from the polluted environments since such species are already adapted to contamination and possess resistance mechanisms. Utilization of bacterial biofilms or consortia could be advantageous due to higher resistance and a combination of several metabolic pathways, and thus, the possibility to remove several heavy metals simultaneously. Novel technologies covered in this review, such as nanotechnology, genetic engineering, and metagenomics, are being introduced to the field of bioremediation in order to improve the process. To conclude, bioremediation is a potentially powerful solution for cleaning the environment.
Highlights
As a result of industrialization, the environment is being polluted with various types of hazardous wastes
Microorganisms have a crucial role in the pollutants fate in the environment, as they play a part in pollutant transport, distribution, properties, transformation, and mineralization
Slurry phase system – the contaminated substrate is mixed with water in a large tank at constant mixing in order to keep the microorganisms in contact with the pollutants
Summary
As a result of industrialization, the environment is being polluted with various types of hazardous wastes. Microorganisms have a crucial role in the pollutants fate in the environment, as they play a part in pollutant transport, distribution, properties, transformation, and mineralization. They have been successfully used for remediation of various types of environmental pollutants, including diverse organic compounds as well as heavy metals [1,2]. Organic compounds can be completely degraded by the microbial metabolism, resulting in the removal from the environment. Trace elements with low toxicity and important roles in physiological, biochemical, and metabolic processes in living organisms (e.g. cofactors for some enzymes, micronutrients, regulators of osmotic pressure, etc.) are iron (Fe), molybdenum (Mo), and manganese (Mn). Long-term irrigation with wastewater containing low heavy metal concentrations can lead to accumulation of metals in soil
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.
