A critical review on occurrence, distribution, environmental impacts and biodegradation of microplastics

Abstract

Microplastics are small plastic particles (<5mm) linked by hydrocarbon atoms. Microplastics are of two types: primary microplastics, which are inadvertently released into the ecosystem as microbeads, plastic pellets and plastic fibres and secondary microplastics, derived from primary microplastics, when macroplastics get decomposed in the presence of UV light or weathering. Sources of contamination by microplastics can be classified as Terrestrial sources and Aquatic Sources. Microplastics are widespread in diverse ecosystems and are spread in different parts of the world, like India, China, Brazil and Malaysia. Recent studies have revealed the toxic effects of microplastics on various biotic and abiotic components. Microplastics can be completely removed from the soil by microbial biodegradation, most preferably bacteria, actinobacteria and fungi. Bacteria, the recurring group of microbes, can degrade pollutants. Actinobacteria, a commonly occurring Gram-positive bacterium, degrade polymer accumulation. Followed by bacteria, fungi are a major group of microorganisms known to degrade microplastics. The current review deals with the type of plastics, their sources, distribution, environmental impacts and degradation using biological methods, preferably microbes, which would further help in understanding the microplastic-mediated adverse effects' molecular mechanism and their removal from the environment using Green Technology. Key words: Biodegradation, Microbes, Microplastics, Toxicity

Microplastic contamination in the Chanthaburi estuarine ecosystem, Eastern part of Thailand

“…Moreover, the environmental degradation involving radiation, thermolysis and microbial degradation transforms primary MPs to hazardous secondary microplastics in the marine ecosystem (Pourebrahimi and Pirooz, 2023). The negative impacts of microplastics are available at all stages of foodweb, exposure route, and interaction with several pollutants (Avinnash et al, 2023). The tiny size of MPs accumulate easily through the ingestion route of marine organisms like: bivalves, mussels, fishes, shrimps and oysters (Auta et al, 2017;Sulaiman et al, 2023).…”

Adsorptive Removal of Famotidine Drug from Aqueous Medium by Ocimum Basilicum

“…[23] Studies have shown that nanomaterials could be effectively applied for the adsorption of microplastics from marine environment. [24,25] Pourabadeh et al [26] used iron nanoparticles for the removal of reactive red 2 from aqueous solution. Shojaei et al [27] studied NaX nanozeolites for the removal of auramine-O and malachite green dyes from aqueous media.…”

“…In another study, chitosan derived nanocomposite was used for the removal of disperse red 60 dye which is found in industrial effluent [23] . Studies have shown that nanomaterials could be effectively applied for the adsorption of microplastics from marine environment [24,25] . Pourabadeh et al [26] .…”