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This review article explores the challenges associated with landfill leachate resulting from the increasing disposal of municipal solid waste in landfills and open areas. The composition of landfill leachate includes antibiotics (0.001–100 μg), heavy metals (0.001–1.4 g/L), dissolved organic and inorganic components, and xenobiotics including polyaromatic hydrocarbons (10–25 μg/L). Conventional treatment methods, such as biological (microbial and phytoremediation) and physicochemical (electrochemical and membrane-based) techniques, are available but face limitations in terms of cost, accuracy, and environmental risks. To surmount these challenges, this study advocates for the integration of artificial intelligence (AI) and machine learning (ML) to strengthen treatment efficacy through predictive analytics and optimized operational parameters. It critically evaluates the risks posed by recalcitrant leachate components and appraises the performance of various treatment modalities, both independently and in tandem with biological and physicochemical processes. Notably, physicochemical treatments have demonstrated pollutant removal rates of up to 90% for various contaminants, while integrated biological approaches have achieved over 95% removal efficiency. However, the heterogeneous nature of solid waste composition further complicates treatment methodologies. Consequently, the integration of advanced ML algorithms such as Support Vector Regression, Artificial Neural Networks, and Genetic Algorithms is proposed to refine leachate treatment processes. This review provides valuable insights for different stakeholders specifically researchers, policymakers and practitioners, seeking to fortify waste disposal infrastructure and foster sustainable landfill leachate management practices. By leveraging AI and ML tools in conjunction with a nuanced understanding of leachate complexities, a promising pathway emerges towards effectively addressing this environmental challenge while mitigating potential adverse impacts. [Display omitted] • Landfills are anticipated to account for 70% of developing country waste. • Landfill leachates are abundant in pollutants like antibiotics, heavy metals and others. • Conventional treatment methods had limitations due to cost, accuracy and risks. • Machine learning tools SVM, ANN and GA can aid in improved leachate treatment. [ABSTRACT FROM AUTHOR]

This communication explores the intricate relationship between food waste and climate change, considering aspects such as impacts, projections, and emissions. It focuses on the pressing issue of waste generation and its potential consequences if current trends persist, and emphasises the importance of efficient solid waste management in improving environmental quality and fostering economic development. It also highlights the challenges faced by developing countries in waste collection and disposal, drawing comparisons with the waste utilisation methods used by developed nations. The review delves into the link between food waste and climate change, noting the paradoxical situation of food wastage against the backdrop of global hunger and malnutrition. It underscores the scientific evidence connecting food waste to climate change and its implications for food security and climate systems. Additionally, it examines the environmental burden imposed by food waste, including its contribution to greenhouse gas emissions and the depletion of resources such as energy, water, and land. Besides environmental concerns, this communication also highlights the ethical and socioeconomic dimensions of food waste, discussing its influence on Sustainable Development Goals, poverty, and social inequality. The communication concludes by advocating for collective action and the development of successful mitigation strategies, technological solutions, and policy interventions to address food waste and its climate impacts. It emphasises the need for collaboration, awareness, and informed decision-making to ensure a more sustainable and equitable future. [Display omitted] • The influence of food waste (FW) on climate change is clarified. • Technological solutions & policy interventions play crucial roles in FW management. • Efficient solid waste management enhances environmental & economic development. • The environmental consequences of FW are explored. [ABSTRACT FROM AUTHOR]

• This review focuses on different methodologies employed for CO 2 transformation into useful products. • Outline of CO 2 emission and capturing methods were discussed. • Detailed reports on photochemical, biochemical and electrochemical CO 2 transformation were highlighted. • Comparison between biological and chemical methods was discussed. • The products obtained from CO 2 conversion were summarized in detail. Carbon dioxide (CO 2), a greenhouse gas is considered to contribute significantly to climate change and global warming. Environmental changes require to minimize the measure of CO 2 in air. The capture, storage and utilization of carbon based on photochemical, biochemical and electrochemical processes are the innovative proposed methods to decrease utilization of nonrenewables such as coal and oil. CO 2 can be reduced chemically through either homogeneous or heterogeneous pathway. In general, photochemical transformation of CO 2 involves formation of carrier charges followed by its separation, transportation and finally reduction of CO 2 using generated photoelectrons. Photocatalytic reduction of carbon dioxide is a rising territory of research. Beginning from the premise of photocatalytic reduction, the investigations about different semiconducting frameworks like oxides, sulfides, and phosphides are considered in this review. Biochemical transformation deals with enzymatic conversion of CO 2 and electrochemical reduction uses electrical energy for converting CO 2 into its reduced form. The enzyme catalytic carbon dioxide change gives an eco-accommodating approach to make carbon-based chemical products. A few favorable circumstances related with enzymatic change incorporate high selectivity, high return, less quantity of waste, less response conditions however certain downsides, for example, staggering expense of catalysts and cofactors, and longer response times as contrasted and normal strategies. Some products obtained as a result of CO 2 reduction includes methanol, formic acid, CO, methane, ethylene and gasoline. In this review, a overview on inalienably associated methodologies is given and ongoing advancement on the improvement, designing, and comprehension of CO 2 reduction using photochemical, biochemical and electrochemical is outlined. [ABSTRACT FROM AUTHOR]

The present work explains the biosorption of malachite green dye from aquatic systems by nano zero valent iron stacked activated carbon (NZVI-AC), which was prepared by dual surface modification strategy. NZVI-AC was characterized by using FTIR, SEM-EDX, XRD and TGA. NZVI-AC exhibited efficient performance in dye biosorption properties. Experimental variables such as time, pH, dye concentration, temperature and biosorbent dosage influenced Langmuir adsorption capacity of 187.3 mg/g. The present biosorption system was best described by pseudo-first order kinetics. The dye was completely knocked out of the solution within 60 min at equilibrium. The thermodynamic behaviour of NZVI-AC was exothermic, feasible and spontaneous. Experimental data was engaged to validate new solid-liquid phase equilibrium model, showing the average absolute relative deviation 7.72%. Hence the procedure was non-toxic, potential to retain biosorbent from the solution, applicable for multiple cycles. In context, NZVI-AC can be recommended for the treatment of dyes from industrial effluent. [ABSTRACT FROM AUTHOR]

Control and prevention of environmental pollution has become a worldwide issue of concern. Aromatic hydrocarbons including benzene, toluene, ethyl benzene, xylene (BTEX) and polyaromatic hydrocarbons (PAHs) are persistent organic pollutants (POPs), released into the environment mainly by exploration activities of petroleum industry. These pollutants are mutagenic, carcinogenic, immunotoxic and teratogenic to lower and higher forms of life i.e. microorganisms to humans. According to the International Agency for Research on Cancer (IARC) and United States Environmental Protection Agency (U.S. EPA), Benzo[ a ]pyrene (BaP) is carcinogenic in laboratory animals and humans. Aromatic hydrocarbons are highly lipid soluble and thus readily absorbed from environment in gastrointestinal tract of mammals. Treatment and remediation of petroleum refinery waste have been shown either to reduce or to eliminate genotoxicity of these pollutants. Bioremediation by using microorganisms to treat this waste is showing a promising technology as it is safe and cost-effective option among various technologies tested. The main aim of this review is to provide contemporary information on variety of aromatic hydrocarbons present in crude oil (with special focus to mono- and poly-aromatic hydrocarbons), exposure routes and their adverse effects on humans. This review also provides a synthesis of scientific literature on remediation technologies available for aromatic hydrocarbons, knowledge gaps and future research developments in this field. [ABSTRACT FROM AUTHOR]

Petroleum is produced by thermal decay of buried organic material over millions of years. Petroleum oilfield ecosystems represent resource of reduced carbon which favours microbial growth. Therefore, it is obvious that many microorganisms have adapted to harsh environmental conditions of these ecosystems specifically temperature, oxygen availability and pressure. Knowledge of microorganisms present in ecosystems of petroleum oil reservoirs; their physiological and biological properties help in successful exploration of petroleum. Understanding microbiology of petroleum oilfield(s) can be used to enhance oil recovery, as microorganisms in oil reservoirs produce various metabolites viz . gases, acids, solvents, biopolymers and biosurfactants. The aim of this review is to discuss characteristics of petroleum oil reservoirs. This review also provides an updated literature on microbial ecology of these extreme ecosystems including microbial origin as well as various types of microorganisms such as methanogens; iron, nitrate and sulphate reducing bacteria, and fermentative microbes present in petroleum oilfield ecosystems. [ABSTRACT FROM AUTHOR]

Anaerobic digestion (AD) has emerged as a promising technology for diverting the organic waste from the landfills along with the production of clean energy. AD is a microbial-driven biochemical process wherein the plethora of microbial communities participate in converting the putrescible organic matter into biogas. Nevertheless, the AD process is susceptible to the external environmental factors such as presence of physical (microplastics) and chemical (antibiotics, pesticides) pollutants. The microplastics (MPs) pollution has received recent attention due to the increasing plastic pollution in terrestrial ecosystems. This review was aimed for holistic assessment of impact of MPs pollution on AD process to develop efficient treatment technology. First, the possible pathways of MPs entry into the AD systems were critically evaluated. Further, the recent literature on the experimental studies pertaining to the impact of different types of MPs at different concentrations on the AD process was reviewed. In addition, several mechanisms such as direct exposure of MPs on the microbial cells, indirect impact of MPs through the leaching of toxic chemicals and reactive oxygen species (ROS) formation on AD process were elucidated. Besides, the risk possessed by the increase of antibiotic resistance genes (ARGs) after the AD process due to the MPs stress on microbial communities were discussed. Overall, this review deciphered the severity of MPs pollution on AD process at different levels. [Display omitted] • Microplastics influence the biochemical pathways of anaerobic digestion process. • Microplastics directly interact with microbial cells and disrupt the cell walls. • Leaching & reactive oxygen species formation are the indirect inhibitory pathways. • Microplastics exposure increases the abundances of antibiotic resistance genes. [ABSTRACT FROM AUTHOR]

Wastewater management has emerged as an uprising concern that demands immediate attention from environmentalists worldwide. Indiscriminate and irrational release of industrial and poultry wastes, sewage, pharmaceuticals, mining, pesticides, fertilizers, dyes and radioactive wastes, contribute immensely to water pollution. This has led to the aggravation of critical health concerns as evident from the uprising trends of antimicrobial resistance, and the presence of xenobiotics and pollutant traces in humans and animals due to the process of biomagnification. Therefore, the development of reliable, affordable and sustainable technologies for the supply of fresh water is the need of the hour. Conventional wastewater treatment often involves physical, chemical, and biological processes to remove solids from the effluent, including colloids, organic matter, nutrients, and soluble pollutants (metals, organics). Synthetic biology has been explored in recent years, incorporating both biological and engineering concepts to refine existing wastewater treatment technologies. In addition to outlining the benefits and drawbacks of the current technologies, this review addresses novel wastewater treatment techniques, especially those using dedicated rational design and engineering of organisms and their constituent parts. Furthermore, the review hypothesizes designing a multi-bedded wastewater treatment plant that is highly cost-efficient, sustainable and requires easy installation and handling. The novel setup envisages removing all the major wastewater pollutants, providing water fit for household, irrigation and storage purposes. [Display omitted] • Wastewater management with affordable and sustainable techniques is of urgent need. • Pollutants ranges from organics to inorganics with high bioaccumulative potency. • Modes and mechanisms of remediation using synbio technologies are illustrated. • The study hypothesized a novel wastewater treatment plant augmented with MFC. • Remediation strategies aimed for economically feasible and easy handling attributes. [ABSTRACT FROM AUTHOR]

Surfactants are one of the most versatile group of chemicals used in various industrial processes. Their market is competitive, and manufacturers will have to expand surfactant production in ecofriendly and cost effective manner. Increasing interest in biosurfactants led to an intense research for environment friendly and cost-efficient production of biosurfactant. Structural diversity and functional properties of biosurfactants make them an attractive group of compounds for potential use in wide variety of industrial, environmental and biotechnological applications. Screening methods make task easier to obtain potential biosurfactant producing microorganisms. Variety of purification and analytical methods are available for biosurfactant structural characterization. This review aims to compile information on types and properties of biosurfactant, microbial screening methods as well as biosynthesis, extraction, purification and structural characterization of biosurfactant using rhamnolipid as a model biosurfactant. It also describes factors affecting rhamnolipid production. It gives an overview of oil recovery using biosurfactant from Pseudomonas aeruginosa . [ABSTRACT FROM AUTHOR]

In recent years, there has been increasing concern over public health threat presented by introduction of petroleum hydrocarbon pollutants in environment due to anthropogenic activities to a greater extent and natural processes to some extent. Many countries all over the world are currently facing severe problem due to these pollutants as they are one of the persistent organic pollutants (POPs). Remediation of polluted sites by biodegradation is a viable option as conventional physico-chemical methods for remediation seems technically as well as economically challenging. Biodegradation is non-invasive and could be cost-effective in removal of petroleum hydrocarbon pollutants. It is considered as ultimate mechanism for pollutants removal. Immobilized microbial cells give advantage over free microbial cells to improve the survival and retention of the bioremediation agents in polluted sites. However, current biodegradation approaches suffer from a number of limitations, which include pollutant characteristics, poor capabilities of microbial communities in the field, lesser bioavailability of pollutants, growth conditions, etc. Understanding the factors affecting microbial degradation is of great research interest in present scenario. This review selectively examines and provides a critical view on bioavailability of the substrates, microorganisms in petroleum hydrocarbon pollutants degradation and the molecular techniques for their characterization, degradation mechanisms under aerobic and anaerobic conditions, commercially available bioremediation agents and factors affecting biodegradation of these pollutants. Role of genetically modified organisms and biodegradation of petroleum hydrocarbon pollutants by immobilized will also be discussed. [ABSTRACT FROM AUTHOR]

Petroleum hydrocarbon pollutants are recalcitrant compounds and are classified as priority pollutants. Cleaning up of these pollutants from environment is a real world problem. Bioremediation has become a major method employed in restoration of petroleum hydrocarbon polluted environments that makes use of natural microbial biodegradation activity. Petroleum hydrocarbons utilizing microorganisms are ubiquitously distributed in environment. They naturally biodegrade pollutants and thereby remove them from the environment. Removal of petroleum hydrocarbon pollutants from environment by applying oleophilic microorganisms (individual isolate/consortium of microorganisms) is ecofriendly and economic. Microbial biodegradation of petroleum hydrocarbon pollutants employs the enzyme catalytic activities of microorganisms to enhance the rate of pollutants degradation. This article provides an overview about bioremediation for petroleum hydrocarbon pollutants. It also includes explanation about hydrocarbon metabolism in microorganisms with a special focus on new insights obtained during past couple of years. [ABSTRACT FROM AUTHOR]