Management of Micro and Nano-plastics in Soil and Biosolids

Microplastics (MPs) and nanoplastics (NPs) have become significant environmental concerns due to their potential adverse effects on marine and human health. These microplastic particles are created by discontinuing more considerable plastic waste or delivered straightforwardly into the climate through different sources. While the impact of microplastics on marine life has been well-studied, their effects on terrestrial ecosystems are still poorly understood. Studies have shown that microplastics can be ingested by various organisms across the food chain, including phytoplankton, zooplankton, fish, and even humans. Once ingested, these particles can accumulate in the organs and tissues of the organism, leading to cytotoxicity and immune responses. Additionally, microplastics can act as carriers for other harmful chemicals and pollutants, further exacerbating their impact on human and environmental health. This study shows that the economic impact of micro- and nanoplastic pollution is also significant, affecting industries such as fisheries, agriculture, transportation, and tourism. The cost of cleanup and the loss of revenue due to the negative perception of affected areas can be substantial. To address the issue of micro- and nanoplastic pollution, it is essential to identify and address the primary sources of plastic waste, promote waste reduction and recycling, and educate the public on the potential harm caused by microplastics. Additionally, research into the use of microorganisms to degrade plastics, particularly those with marine origins, may provide a more sustainable solution to the problem of microplastic and nanoplastic contamination.

Microplastics and nanoplastics have emerged as pressing environmental pollutants as a consequence of their ubiquitous presence and potential adverse effects on aquatic ecosystems. These small plastic particles present complex and multifaceted challenges to the health and integrity of aquatic environments. Microplastics and nanoplastics originate from an assortment of sources, such as the disintegration of bigger plastic objects, synthetic textiles, and personal care items. Due to their small size, they can be consumed by a broad variety of aquatic organisms, from plankton and mollusks to fish and marine mammals. The ingestion of these particles can lead to physical harm, as they may accumulate in the digestive tract, causing blockages, inflammation, and reduced nutrient absorption. Furthermore, these plastics can adsorb and concentrate toxic pollutants from the surrounding water, functioning as conduits for the transfer of hazardous compounds into the food web. This comprehensive review explores the diverse and intricate impacts of microplastics and nanoplastics on the aquatic environment, encompassing freshwater and marine ecosystems. It provides an overview of their sources, distribution, and abundance, emphasizing their persistence and potential pathways of entry. The interactions of microplastics and nanoplastics with aquatic organisms are examined along with the ingestion patterns, trophic transfer, and potential biomagnification. Beyond physical and chemical repercussions, behavioral changes in aquatic organisms attributable to micro- and nanoplastics are highlighted. This chapter also delves into the influence of micro- and nanoplastics on biogeochemical cycles, ecosystem dynamics, and ecotoxicological effects. This chapter underscores the urgent need for interdisciplinary research and concerted efforts to address this escalating environmental challenge and emphasizes the importance of preventative measures, regulations, public awareness, and ongoing scientific investigation.

Microplastics are less than 5 mm in diameter, composed of various chemical constituents, and come from numerous sources. Because of wide use and irrational disposal of plastics, microplastics have become a major environmental problem on a global scale. Increasing level of microplastics in the ecosystem is causing undesirable impacts on the terrestrial and marine ecosystem. Therefore, the application of a novel methodology to remove microplastics from the environment has become essential. Bioremediation is regarded as an eco-friendly and greener remediation method among some commonly used ones for microplastics. Numerous biotic and abiotic variables frequently have an impact on the bioremediation of plastics. It is essential to understand the key pathways that living things use in order to use plastic fragments as their only source of carbon for development and growth. In this context, the authors have discussed the different sources of microplastics, the effect of microplastics on ecosystem, and the role of microbes in biodegradation of microplastics present in the environment. Additionally, this chapter advances knowledge of how microplastics behave in ecosystems and offers a theoretical framework for more accurate evaluation of the ecological and environmental risks associated with microplastics, as well as their opportunities, challenges, and prospective research directions.

Although plastic, due to its durability, low cost, and versatility, has contributed to the development of society and has made people’s lives convenient, its drastic increase in manufacturing and production with limited measures for its management and disposal has led to a substantial accumulation in the environment. Due to its universal distribution, plastic is acknowledged as a global problem. More than half a century ago, scientists stated the existence of minute plastic elements in oceans, and since then, numerous studies have documented evidence of microplastics (MPs) and nanoplastics (NPs) in diverse ecosystems including terrestrial, atmospheric, aquatic, and biota. As per the US National Oceanic and Atmospheric Administration, MPs measure <5 mm in diameter, whereas NPs are <100 μm in diameter. Over the last decade, the increasing concentration of MPs and NPs in aquatic ecosystems is documented as a serious environmental issue. Stormwater is known to be a key contributor to MP and NP pollution in the aquatic ecosystem, as it does not undergo any treatment before entering the aquatic environment and levels of pollutants in stormwater are not regulated. The prominent sources of MPs and NPs in stormwater are tire and road wear particles, single-use plastic products, and wastewater treatment plant effluents. These MPs and NPs are taken up by the organisms and get accumulated in the biota; these small particles can also enter the roots of plants and enter the food web. Although many steps have been taken by regional, national, and international regulatory bodies, these appear to be ineffective in curbing plastic pollution on a large scale. Management and preventive strategies need to be undertaken along with consumer awareness programs and the development of waste management infrastructure.

Globally, abiotic and biotic components are presently under the greatest threat due to an alarming increase of micro-nanoplastics (MNPs) in the environment. MNPs are ingested, inhaled, or absorbed through the food chain and reach the agroecosystem, animals, and human bodies. They can impair fertility, behavioral disorders, and obstruct the blood–brain barrier. It is essential to pinpoint the sources of microplastics (MPs) in the environment and take preventative measures to lessen their negative effects on the environment. Compared to terrestrial ecosystems, aquatic or marine environments have been extensively studied for microplastic pollution. Much research occurs on the mitigation of microplastic effects on many ecosystems. In this chapter, we provide a comprehensive overview of current research and trends in microplastics in the environment. The effects of microplastics on various aspects, including the environment, soil organisms, plants, food webs, and human health, are discussed. The authors explore research gaps and highlight future research areas in micro-nano-plastics.

The extensive use of plastic has resulted in severe environmental, social, economic, and health issues. Mismanagement of plastic waste leads to the accumulation of micro–nanoplastic (MNP) pollution in the environment. The use of microplastic-containing fertilizers, such as bio-waste from households, sewage sludge, or commercial sources, is believed to be the primary source of MNP contamination in agricultural farmland. Plant performance can be affected by MNPs, either directly or indirectly. Several studies found that nanoplastics (NPs) smaller than 1 μm can be uptake directly by plants. The uptake of NPs by plant roots involves their transport across the plasma membrane of root cells, loading, and subsequent translocation through the xylem pathway. It indicates that NPs taken by roots or leaves can be translocated to another part of the plant through the plant’s vascular bundle. The extended adverse effect of uptake MNPs on plants will be briefly discussed. MNPs can alter the physical and chemical properties of soil, impacting microbial community structure and function and indirectly disturbing plant nutrient cycling and uptake. This chapter unravels the complex relationships between soil microbes, microplastics, and plants and their impact on plant performance. Furthermore, future perspectives for mitigating and solving MNP pollution and the impact on plants are also offered.

Various organic and inorganic contaminants have been detected in soil systems among which heavy metals are one of the most studied ones. Additionally, micro-nanoplastics have been introduced as recent contaminant into soil systems by composting, mulching, biosolid applications, waste disposal, surface run-off, and air deposition. While the fate and toxicity of heavy metals in soil systems have been studied thoroughly, further research in the presence of micro-nanoplastics revealed requirement to investigate interaction of micro-nanoplastics and heavy metals in soil systems. Mechanisms such as adsorption, complexation, and biotransformation have been explored to understand the interaction between micro-nanoplastics and heavy metals. Literature about mechanisms and interactions indicates that micro-nanoplastics can play a role as a vector for the fate of heavy metals in soil systems depending on various parameters related with environmental conditions and contaminants. Therefore, heavy metals may behave differently when they co-exist with micro-nanoplastics. In relation to this change in the fate of heavy metals in soil systems, their toxic effects on soil organisms could be altered. In this chapter, physical, chemical, and biological mechanisms that affect the interaction of micro-nanoplastics and heavy metals are presented. Also, environmental implications are discussed within the context of mobility and toxicity.

Micro-nanoplastics (MNPs) are emerging contaminants that have been broadly identified as a danger to soil systems. MNPs are able to show toxicity and interact with heavy metals and other toxic elements in the soil systems, affecting soil productivity and causing toxicity. Earthworms are well recognized as farmers’ friends and their presence is important for retaining soil efficiency and health. The presence of MNPs significantly impacts soil macrofauna such as earthworms showing various harmful effects including mortality and reproductive toxicity. Keeping in view the above facts, this chapter focuses on the MNPs, including their source and characteristics in the soil environment, and their toxicity to earthworms. Furthermore, the combined effect of MNPs with heavy metals and organic pollutants along with the crucial challenges and future perspectives in reducing MNPs in soil environment are also discussed.

Microplastics and nanoplastics (M/NPs) are ubiquitous in soil environment because of agricultural, industrial, and waste management activities. They can spread and age in soil due to the physical, chemical, or biological factors related to soil and plastics. Their fate in soil environment mainly depends on their adsorption capacities to soil and other contaminants. Their spread, aging, and fate in soil determine their bioavailability for soil fauna. Bioavailable fraction of micro and nanoplastics is partitioned into terrestrial organisms based on the toxicokinetics principles. Although the toxicodynamics of M/NPs, including at cellular and organism levels, has been studied relatively commonly, their toxicodynamics at the macromolecular level and toxicokinetics have not been investigated properly, yet. Moreover, the mixture of toxicological effects of M/NPs with other emerging contaminants and heavy metals is still in its infant stages in the literature. These studies should be advanced with mechanistic understandings in order to make contribution to environmental risk management of M/NPs. As a future outlook, the toxicity of M/NPs may need a different insight when the circular economy principles will be adopted widely and released M/NPs may have unusual characteristics due to the shift in waste management.

Micro/nanoplastics are new global pollutants that have drawn major attention globally due to their potential to damage the ecosystem upon their persistence and accumulation. Micro/nanoplastics (MNPs) are inextricably released into the environment by terrestrial and land-based sources, particularly runoffs, and can be found in the majority of commonly used items in the form of primary microplastics or produced by the fragmentation of larger plastics as secondary microplastics. In recent decades, MNPs have been found to accumulate in the Earth’s environment, tissues, and gastrointestinal systems of animals including humans. These plastics are nonbiodegradable and their presence in air, soil, water, and food has led to ecotoxicological concerns and threats to biodiversity. Apart from this, due to their tiny size, the risks associated with their entry into the food chain are that they are taken up by plant roots and ingested by soil-dwelling fauna, causing morphological deformations, organ damage, and physiological malfunctions. Bioaccumulation of MNPs in plants has been identified to generate oxidative stress, which could alter gene expression and many metabolic pathways involved in plant growth, biomass production, and secondary metabolite synthesis. Many new methods for MNP analyses have been developed, while older technologies were repurposed that enabled the estimation in terms of scope and magnitude of plastic pollution up to nano-size range. Given the plastic threat’s pervasiveness and severity, this chapter provides a general overview of the occurrence, fate, and impacts of MNPs in soils, focusing on their ecological consequences.

A new threat has been unlocked for the past decade is that microplastics and nanoplastics can potentially adsorb other environmental pollutants. Acting as a vector they can transfer and exacerbate the bioavailability of several contaminants in different environmental compartments. The adsorption and interaction can be influenced by several factors including the micro-nanoplastic characteristics and the matrices in contact. Accordingly, it should critically look into the possibilities of natural aging and weathering processes that can alter the plastic properties, which can induce surface assimilation. Despite the investigations carried out so far, the adsorption behavior and interactions and long-term fate still need to be better understood. Consequently, this chapter reviews the current knowledge on the adsorption behavior and interaction of micro and nanoplastics in soils and aquatic environments, including the factors influencing adsorption, the mechanisms and interactions involved, and the impacts of adsorption. The chapter also addresses the current challenges and the methodological gaps in understanding the adsorption behavior and interaction of micro and nanoplastics with possible future research outlooks to fulfill these gaps.

The issue of (micro) plastic pollution has received much attention. The fate of discarded biodegradable plastic products (plastic bags, lunch boxes, etc.) entering the engineering environment (aerobic composting and anaerobic digestion) with food waste, as well as the (micro) plastic environmental risks associated with their application, is not yet clear. Therefore, this chapter summarizes current related academic research and focuses on the impact of two different biological treatment methods on biodegradable plastics. At the same time, the potential environmental risks of microplastics after the use of food waste compost products and biogas residue on land were identified (including soil material turnover, microorganisms, and micro animals). Finally, corresponding prevention and control measures (such as extending composting time, increasing temperature for anaerobic digestion, bioremediation of earthworms, etc.) are proposed to reduce the occurrence of microplastics in the soil.

Microplastics (MPs) transferred to sludge during water treatment processes, particularly wastewater treatment, enter anaerobic digesters through sludge treatment prior to its final disposal or reuse. MPs retained in digested sludge confirm the presence of MPs during anaerobic sludge digestion. The abundance of MPs in anaerobic digesters varies considerably from 0.02 MPs/g DW to 169,000 MPs/g DW of sludge. MPs’ variability in digested sludge is partly attributed to the influent quality and treatment capacity of a wastewater treatment plant. Fibrous MPs are the most common MPs detected. The MPs in digested sludge usually have sizes less than 1 mm. Common MPs retrieved are those of acrylic, polyamide, polyethylene, polyester, and polyethylene terephthalate. In anaerobic digesters, MPs could interact with organic matter causing increased solubilization, which leads to higher formation of volatile fatty acids. Contrarily, they could impede the digestion of organic matter. They could interact with emerging pollutants and reduce their negative impacts on anaerobic digestion through adsorption on MPs. MPs could change the microbial profiles of anaerobic sludge digesters, favoring some microbes while inhibiting others. Polyamide monomers were found to promote the growth of certain microbes, causing increased biogas production. Inhibitory effects are often due to the leaching of chemicals, particularly bisphenol A, from MPs. MPs undergo morphological and chemical changes in anaerobic digesters. They have thinner surfaces at certain sites and cleavages after digestion. Their abundance reduces after digestion, implying potential degradation or biodegradation. This makes anaerobic sludge digestion a prospective avenue for MP removal through bioaugmentation and sludge pretreatment.

The presence of microplastics (MPs) as a global contaminant has gained increasing attention, particularly in relation to water pollution. However, research on MPs in sewage sludge remains restricted in comparison. MPs originating from many sources accumulate inside sewage systems, with a significant portion becoming entrapped within the sludge throughout the sewage treatment process. Consequently, the sludge not only serves as a sink for MPs but also as a source of MPs. The utilization of sludge in soil amendments offers the advantage of nutrient provision while potentially introducing a significant microplastic (MP) content into the soil. However, it is important to acknowledge the associated environmental hazards. MPs that have accumulated in the soil can alter its properties and migrate, leading to the contamination of subsurface soils and groundwater. Furthermore, it is important to consider the adsorption of heavy metals and organic pollutants by microplastics (MPs) in sewage sludge, given that these pollutants are often present in significant quantities within the sludge. The coexistence and interplay of microplastics (MPs) and the pollutants they absorb might amplify the environmental hazards, hence enhancing the possibility of their absorption by plants. There is a need for further exploration and investigation of MPs in soil amendments as they can cause long-term risks to the environment. Therefore, this chapter focuses on MPs in sludge, sources of MPs in sewage sludge, and their sampling, separation, and identification methods.

Microplastics (MPs) and nanoplastics (NPs) have become increasingly alarming subjects due to their widespread presence and their potential harm to the environment. The micro-nano plastics (MNPs) are emerging as an environmental hazard as they enter the agroecosystem, plants, animals, and human body via trophic levels, through ingestion or inhalation, causing a variety of issues such as disruption in the blood-brain barrier, abnormalities, and reduced fertility. Therefore, it is essential to create innovative MNP remediation techniques for their removal from the natural environment. Microbial remediation, one of the available techniques, has the potential to be a successful green technique for destroying/recovering MNPs. The breakdown of MNPs by microorganisms like bacteria, fungi, and microalgae in both axenic and mixed cultures can be viewed as an environmentally sustainable method for addressing the issue of microplastic pollution. As microbial remediation techniques rely on various biotic and abiotic factors, including temperature, pH, and oxidative stress, it is now possible to manipulate these factors to bring about changes in plastic pollutants. Therefore, it is important to identify the primary pathways that microbes use to break down plastic components as the only carbon source used by microorganisms for their growth and development. In this chapter, the role of different microorganisms and their enzymatic processes in degrading MNPs in diverse environmental compartments, such as wastewater (WW) streams, municipal sludge, municipal solid waste (MSW), and composting, is described. The chapter also discusses the advantages and disadvantages of several MNP remediation technologies, including enzymatic, advanced molecular, and biomembrane systems, as well as their potential for further study.

Plastic is the most common man-made polymer. It possesses greater flexibility, durability, lower manufacturing cost, and lighter weight, leading to increased consumption and production of single-use plastics. In developed countries, plastic materials are used in packaging, construction, automobiles, medical devices, furniture, toys, etc. Improper disposal of plastic waste and poor degradation lead to massive accumulation in the environment. It degrades naturally with the help of sunlight, heat, oxygen level, and salinity into micro-nanoplastics (MNPs). The produced MNPs are major sources of plastic pollution affecting our entire ecosystem directly or indirectly, by emitting plastic waste contaminants for decades. The conventional method of micro-nanoplastic degradation produces highly toxic compounds, posing environmental and health risks. Bioremediation is considered to be a better alternative method for degrading MNPs. A combined research strategy is required for utilizing various technologies to enhance the remediation of MNPs. At present, the incorporation of nanotechnology, membrane technology, and enzyme technology has improved the bioremediation (BR) process. For instance, the interaction of nanoparticles such as SiO_2, and fullerene 60 with microorganisms was found to decrease the lag phase and increase the biodegradation (BD) rate. The current review focuses on a comprehensive view of the microbial nanobioremediation (NBR) process to address the environmental issues caused by MNPs.