Biodegradation aspects of Polycyclic Aromatic Hydrocarbons (PAHs): A review

https://cyberleninka.org/article/n/567486.pdf

A review on polycyclic aromatic hydrocarbons: Source, environmental impact, effect on human health and remediation

Polycyclic Hydrocarbons Vol. 1. Pp. xxvi + 487. 126S. (With a chapter on carcinogenesis by Regina Schoental.) Vol. 2. Pp. lvii + 487. 140s. By E. Clar. (London and New York: Academic Press; Berlin: Springer-Verlag, 1964.)

Polycyclic Aromatic Hydrocarbons

Effects of biochar and greenwaste compost amendments on mobility, bioavailability and toxicity of inorganic and organic contaminants in a multi-element polluted soil.

Fluoride removal from water by adsorption—A review

Defluoridation of groundwater using brick powder as an adsorbent.

The water samples were collected from River Ganga in Rishikesh during December 2008 to assess its suitability for drinking, irrigation, and industrial usages using various indices. Based on the values obtained and suggested designated best use, water in upper segment can be used for drinking but after disinfection (Class A); organized outdoor bathing in middle segment (Class B); and can be used as drinking water source (Class C) in lower segment in Rishikesh. All the parameters were within the specified limits for drinking water quality except E. coli. The indices of suitability for irrigation and industrial application were also evaluated. The irrigation quality ranged from good to excellent at almost all places with the exception of percent sodium. The abundance of major ions followed K+> Ca2+> Cl− > HCO3
 − > Na+> Mg2+> CO3
 2− trend. The major cations suggested that the water is alkaline (Na + K) than alkaline earth (Ca + Mg) type. The heavy metals (Pb, Cu, Zn, Ni) were found either absent or within the limits specified. There was no specific industrial input of pollutants. Industrial applications of the river water should be limited since the water was found to be aggressive, based on Langelier saturation index (0.3) and Ryznar stability index (8.8), with the problem of heavy to intolerable corrosion. Water quality of Ganga in Rishikesh was good with exception of most probable number (MPN) which needs regular monitoring and measures to control.

https://link.springer.com/content/pdf/10.1007%2Fs13201-014-0235-1.pdf

Assessment of water quality and suitability analysis of River Ganga in Rishikesh, India

Polyaromatic hydrocarbons (PAHs) are considered as hazardous organic priority pollutants. PAHs have immense public concern and critical environmental challenge around the globe due to their toxic, carcinogenic, and mutagenic properties, and their ubiquitous distribution, recalcitrance as well as persistence in environment. The knowledge about harmful effects of PAHs on ecosystem along with human health has resulted in an interest of researchers on degradation of these compounds. Whereas physico-chemical treatment of PAHs is cost and energy prohibitive, bioremediation i.e. degradation of PAHs using microbes is becoming an efficient and sustainable approach. Broad range of microbes including bacteria, fungi, and algae have been found to have capability to use PAHs as carbon and energy source under both aerobic and anaerobic conditions resulting in their transformation/degradation. Microbial genetic makeup containing genes encoding catabolic enzymes is responsible for PAH-degradation mechanism. The degradation capacity of microbes may be induced by exposing them to higher PAH-concentration, resulting in genetic adaptation or changes responsible for high efficiency towards removal/degradation. In last few decades, mechanism of PAH-biodegradation, catabolic gene system encoding catabolic enzymes, and genetic adaptation and regulation have been investigated in detail. This review is an attempt to overview current knowledge of microbial degradation mechanism of PAHs, its genetic regulation with application of genetic engineering to construct genetically engineered microorganisms, specific catabolic enzyme activity, and application of bioremediation for reclamation of PAH-contaminated sites. In addition, advanced molecular techniques i.e. genomic, proteomic, and metabolomic techniques are also discussed as powerful tools for elucidation of PAH-biodegradation/biotransformation mechanism in an environmental matrix.

A comprehensive review of metabolic and genomic aspects of PAH-degradation.

Soil is an important environmental matrix to support the life of all organisms directly or indirectly. Despite being the ultimate sink for all pollutants, it has been neglected for long, which has negatively affected the quality of the soil. Disposal of pollutants has resulted in changes in properties of soils and introduction of toxicity into it. The presence of heavy metals, pesticides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons (PAHs) affects all forms of life since these chemicals have associated toxicity, mutagenicity, and carcinogenicity. PAHs are typical pollutants of soil which result in alteration in grain size, porosity and water-holding capacity of soil and affect diversity/population of microbes adversely. Significant changes in permeability, volume, plasticity, etc., are also brought about resulting in poor quality of contaminated soils. Considering the toxicity and global prevalence of PAHs, remediation of contaminated soils has become a challenge. Therefore, it is important to understand the detailed mechanism of physical, chemical or biological changes in soil. Simultaneously, it becomes pertinent to identify the environmentally sustainable treatment options for remediation of contaminated sites. Whereas physical and chemical treatment methods are either cost, chemical, or energy prohibitive, the biological treatment is emerging as an efficient and effective option which employs microorganisms for mitigation. Microorganisms are known for their enzyme-catalyzed catabolic activity when degradation/mineralization of a pollutant is aimed at and can prove useful in degradation of PAHs. Therefore, the present study reviews the effects of PAHs on soil properties, different remediation techniques and the role of microorganisms in remediating contaminated sites.

A. K. Haritash

Papers

Biodegradation aspects of Polycyclic Aromatic Hydrocarbons (PAHs): A review

Defluoridation of groundwater using brick powder as an adsorbent.

Assessment of water quality and suitability analysis of River Ganga in Rishikesh, India

A comprehensive review of metabolic and genomic aspects of PAH-degradation.

Polycyclic aromatic hydrocarbons: soil pollution and remediation