Hazardous Components of Landfill Leachates and Its Bioremediation

Abstract

Landfill leachates contain both dissolved and suspended material and may pose a threat to the environment because of the toxic substances that it carries and contaminates surface water and groundwater. They are composed of several different categories of components out of which many of them are recalcitrant and highly toxic. Major components of landfill leachates are dissolved organic compounds, inorganic macro compounds, heavy metals such as copper, lead, cadmium, chromium, nickel etc. and xenobiotic compounds such as polychlorinated biphenyls. Complex organic compounds which are released from industrial effluents like perfluorooctanoic acid and benzothiazole are also common in many of the landfill leachates. Biological treatment is a low cost effective method for the treatment of landfill leachates which can act as an accelerator for further treatment by either chemical or physical method. Improved strategies have been developed in the biological treatment of leachates which shows the efficiency of the system. But, as leachate characteristics vary depending on the rainfall and other environmental factors, it is important to first thoroughly analyze the physical and chemical properties of the landfill under study. A combined effort involving proper analysis of the leachate components, monitoring leachate flow, risk assessment, and treatment of the leachate before its release is required to efficiently control its impact to the environment.

Culture-based and culture-independent approach for the study of the methanogens and obligate anaerobes from different landfill sites

“…Furthermore, the black-colored liquid leachate released from moisture trapped in landfills contains many pollutants and pathogens. If untreated, leachate discarded in soil or freshwater bodies causes groundwater and surface water pollution and induces eutrophication, hypoxia, fish death and the spread of pathogens in the community ( Christensen et al, 1992 ; Reinhart and Grosh, 1998 ; Kjeldsen et al, 2002 ; Bhalla et al, 2012 ; Giang et al, 2018 ; Ferronato and Torretta, 2019 ; Salam and Nilza, 2021 ). The potential of landfill and landfill leachate in the spread of pollutants and pathogens in nearby communities and its contribution to greenhouse gas emission, ecological and soil health, contamination of surface and groundwater, effects on the release of toxic gases on garbage burning, and spread of antimicrobial resistance have been reviewed by different groups across the world including, China, Iran, South Africa, and India ( Njoku et al, 2019 ; Nair, 2021 ; Parvin and Tareq, 2021 ; Ajay et al, 2022 ; Cheng et al, 2023 ; Fazzo et al, 2023 ; Ghosh et al, 2023 ; Kooch et al, 2023 ; Lee et al, 2023 ; Liang Y. et al, 2023 ; Liang Z. et al, 2023 ; Ma et al, 2023 ; Naveen, 2023 ; Pan et al, 2023 ).…”

An Overview of Treatments for Ultraviolet Quenching Substances (UVQS) and Per- and Polyfluoroalkyl Substances (PFAS) Removal from Landfill Leachate

“…Pollutants in municipal landfill leachate are toxic organic and inorganic compounds, including microorganisms [8,9]. The most common specific categories of pollutants found in leachates include dissolved organic matter, trace ions, xenobiotic organics such as polychlorinated biphenyls or pesticides, and ammonia [10,11]. However, leachates can also release heavy metals, polychlorinated organic compounds, and emerging contaminants into the ecosystem [12][13][14].…”

Purposely Development of the Adaptive Potential of Activated Sludge from Municipal Wastewater Treatment Plant Focused on the Treatment of Landfill Leachate

“…An unknown number of hazardous substances with different chemical structures and variable concentrations can be found in leachate. Many studies identify a high diversity of xenobiotic compounds-hydrophobic aliphatic and aromatic organic substances (benzene, toluene, ethylbenzene and xylenes-BTEX), polyaromatic hydrocarbons, toxic metals, phenols, phthalates, pesticides, microplastics, polyethylene, plasticizers, halogenated organic compounds like PCBs (polychlorinated biphenyls) and dioxins, PFAS (per-and polyfluoroalkyl substances) [11][12][13][14]. These dangerous substances have high synergetic toxicity and their release into the environment represents a serious ecological threat.…”