No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
The potential of microplastics as carriers of metals
Abstract
Microplastics can adsorb chemical pollutants such as metals or pharmaceuticals, and transferred them along the food chain. In this work, an investigation of the adsorption of Cd, Co, Cr, Cu, Ni, Pb and Zn by five different types of microplastics was performed in Milli-Q water and natural waters (seawater, urban wastewater and irrigation water) via a series of batch adsorption experiments. The effects of concentration of metals and physicochemical characteristics of polymers were particularly studied. Results revealed a significant adsorption of lead, chromium and zinc on microplastics, especially on polyethylene and polyvinyl chloride. In the case of polyethylene terephthalate, it showed little adsorption capacity. Specific surface, porosity and morphology are characteristics that affect the molecular interactions. The adsorption isotherms were better described by Langmuir model, which indicates that the main adsorption mechanism might be chemical adsorption. Finally, results obtained in natural waters indicated that dissolved organic matter may play a major role on metal adsorption on microplastics. Results showed an enhancement of metal adsorption in waters with high chemical and biological oxygen demands as urban wastewater and irrigation water.
... Comparison of the results obtained in our study and published in the literature shows that the maximum monomolecular adsorption on the surface of the MP can be influenced by many factors, such as the nature of the MP, the characteristics of its surface, the setup of sorption experiments and the concentration of metal additives for the preparation of model solutions [4,13,39,40]. Thus, the results obtained to characterize the sorption capacity of the PET surface in model solutions based on distilled and artificially created natural water with high concentrations of metal additives (mg/L) exceed the obtained values by 3-4 orders of magnitude ( Table 3). ...
... The concave section obtained in this study at the Ni, Pb and Cu sorption isotherms (Fig. 5) corresponds to the region of low concentrations of metals, namely their content in the natural water of the central part of Lake Onego. Apparently, the inflection point and the appearance of a second plateau on the isotherms of these metals (Fig. 5) is the result of a strong interaction between adsorbed molecules, as a result of the processes of complexation of metals with organic matter [35,39,43,44], as well as competitive sorption on the surface of microplastics under the influence of organic matter, Fe and Mn hydroxides and other metals in the composition of water [13,26,39]. A change in the state of the dissolved substance when a certain concentration of it is reached in solution leads to the appearance of a maximum at isotherms of classes L and S, observed by us on experimentally obtained adsorption isotherms of Co, Cd and Cu (Fig. 4). ...
... The best correspondence between experimental and model data is obtained for Ni, the sorption process of which is equally well described by both the nonlinear Langmuir model and the Freundlich model. At the same time, the inapplicability of both models to describe the sorption process of Cu, Pb and Ni-in the range of low concentrations, and Co, Cd and Pb-in higher concentrations is most likely due to the influence of the complex, multicomponent composition of natural waters on the sorption process [34,35,43,44] and physico-chemical properties of the microplastic surface [13,44]. ...
... With their large surface to volume ratio and hydrophobicity, MPs are effective in adsorbing many pollutants from the environment, such as heavy metals, typically through van der Waals interactions, hydrogen bonding, and surface complexation (Brennecke et al., 2016;Hodson et al., 2017). As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn have been found to accumulate on surface of beached MPs (Godoy et al., 2019;Ta and Babel, 2023) and higher concentrations of heavy metals adsorbed by MPs than ambient water column and sediment were detected (Brennecke et al., 2016;Patterson et al., 2020). The sorption capacity of MPs to heavy metals is associated with the physical and chemical properties of MPs and can be altered by weathering, due to the formation of anion active sites and increased porosity (Holmes et al., 2014;Turner et al., 2020;Mao et al., 2020). ...
... The mechanical abrasion and biodegradation MPs are subjected to also results in a rougher surface, which may provide more active adsorption sites (Fig. 1). Previous studies also found high adsorption capacity for MPs exposed to environmental factors (Brennecke et al., 2016;Godoy et al., 2019;Turner et al., 2020). Unlike other polymers that contain large quantities of electronegative functional groups, PE microbeads were observed to aggregate, indicating that there was little repulsion between each particle (Montes Ruiz-Cabello et al., 2015;Alimi et al., 2018). ...
... The increased intensity of the C--O peak for PET did not lead to the increased Hg adsorption (Fig. S5). This behavior may arise from leaching PET fillers that can enhance the adsorption of pollutants (Bayo et al., 2017;Godoy et al., 2019). ...
... No such phenomenon was observed for the other two plastics. Previous studies confirm that pristine LDPE can adsorb metal ions from solutions (Ashton et al., 2010;Gao et al., 2021;Godoy et al., 2019;Holmes et al., 2012;Huang et al., 2020aHuang et al., , 2020bWang et al., 2020). This phenomenon is dependent on the properties of a given plastic and whether it exhibits adsorption properties towards metal ions (Zou et al., 2020). ...
... Furthermore, PE is characterized by rubber-like properties (amorphous) (Godoy et al., 2019) that promote the surface adsorption of metal ions. The point of zero charge (PZC) determined for untreated PE ranges between 3.2 and 4.5 (Godoy et al., 2019;Shen et al., 2021;Wang et al., 2020), which confirms that LDPE surfaces are negatively charged under the conditions studied here (pH 5.9 to 7.3, Table 2). The negative charge on the LDPE surface promoted electrostatic interactions with the positively charged metal ions, leading to removal from solution. ...
... The negative charge on the LDPE surface promoted electrostatic interactions with the positively charged metal ions, leading to removal from solution. The PZC values of PP and PET are higher than for PE, approximately 5.6-and 6.2-fold, respectively (Godoy et al., 2019), which suggests that during the present study the surface of these plastics either had a neutral charge or very weak negative charge (that is, weak or no interactions with metal ions). Godoy et al. (2019) confirmed that PE has a higher adsorption ability than PET and PP. ...
Plastic waste is increasing and is a serious environmental problem. Among the threats associated with plastics is the release of contaminants into the environment. This study aimed to evaluate the efficiency of metals release from plastics (low-density polyethylene (LDPE), polyethylene terephthalate (PET), and polypropylene (PP)) as affected by different soil solution types, artificial root exudates, and distilled water. The extent of metal release varied depending on the type of solution and plastic used. Metals were leached most effectively from plastics in soil solutions, followed by root exudates, and least effectively by distilled water. LDPE released the highest concentrations of Cu and Na into solution, PP released the greatest amount of Fe, and PET released the most Cr. The efficiencies of Mg and Zn release from the plastics (PP and PET) varied by solution type. Among the plastics studied, LDPE exhibited the strongest ability to adsorb metals, such as Fe, Cr, Mg, and Zn from soil solutions. The amount of metal released from the plastics was also dependent on pH, dissolved organic carbon (DOC) concentrations, and the electrical conductivity (EC) of the solutions. Moreover, plastic extracts were found to have negative effects on germination and growth in Lepidium sativum.
... The adsorption of metals onto MPs can be explained by a variety of best-fit isotherms. The Langmuir model is the most popular and practical isotherms model for the investigation of heavy metal adsorption on MPs, which indicates the primary mechanism of chemisorption [16]. The chemical properties of heavy metals, the nature and features of polymers, and environmental conditions like pH, salinity, and variations in background pollutant concentrations all impact the adsorption process [10]. ...
... The reduction of heavy metal toxicity and bioavailability was observed when combining MPs with heavy metal [21,22] due to the adsorption ability of heavy metals on microplastics [14]. The adsorption isotherms were better described by the Langmuir model, which indicates the main mechanism as chemisorption [16]. The results of the present study are in line with previous studies where the increment of ANC was observed for the combined treatment compared to individual treatments as shown in Fig. 3 m-p and Fig. 4. ...
There is growing recognition of the impact of the rising presence of microplastics (MPs) on terrestrial plant growth and, in general, the terrestrial ecosystem. Simultaneously, there is growing heavy metal accumulation in agricultural lands at an astonishing rate owing to the overwhelming use of chemical fertilizers, herbicides, and weedicides. Thus, there is a need to investigate the synergetic effect of MPs along with heavy metals on the inducing combined toxicity. This study investigates effects at smaller exposure periods of a few hours using a novel optical imaging technique, Biospeckle Coherence Tomography. Biospeckle Optical Coherence Tomography (bOCT) is a novel optical imaging technique that we successfully demonstrated earlier in visualizing the internal activity of plants. Previous studies of authors using the bOCT technique have demonstrated its potential in the independent application of polyethylene microplastic (PEMPs) as well as zinc within 6 h after their treatments. The strong inhibitory effect of 100 mg L⁻¹, Zn, and PEMPs alone on the germination of Lens culinaris could be visualized with bOCT. The current study demonstrated that against expectation, combined effects of Zn toxicity were reduced when combined with MPs. This is suggested due to the significant reduction of Zn uptake by the seedlings through the interaction of Zn and MPs in an aqueous solution. Mass-spectrometry results also indicate a reduced intake of Zn. Our findings suggest that PEMPs could be able to reduce the over-availability of Zn, thus mitigating the Zn toxicity on lentils.
... Microbeads from cosmetics and polymer fibers from clothing are both known to end up in wastewater treatment facilities [39]. According to Godoy et al. (2019), there are two main types of analysis used to characterize MPs: physical and chemical. Size distribution, shape, and color are only some of the physical properties that may be analyzed when characterizing MPs [40,41]. ...
... Adsorption of metals on MPs is significantly influenced by the existence of dissolved organic matter inside surrounding water [198]. The existence of organic matter within a solution can potentially increase the number of binding sites available for pollutants or, alternatively, compete with metal ions that have been adsorbed onto the surfaces of MPs [199]. ...
Microplastics are often found in the greatest quantities in terrestrial environments, in addition to those found along coasts and in oceans. They may get into water bodies from a variety of different sources such as deposition from the atmosphere, runoff from polluted land, and effluent from municipal treatment plants. The objective of this study is to conduct a comprehensive evaluation of the existing scientific literature related to microplastics in wastewater. Specifically, the focus is on investigating the possible impacts of wastewater containing microplastics on both aquatic and terrestrial biota. Additionally, this study attempts to identify any gaps in the current research, with the intention of informing future research priorities in this field. A comprehensive selection of over 200 scientific papers on the subject of microplastic pollution, covering the years 2000–2023, has been selected from a prominent scientific database. These papers encompass a wide range of topics, including recent advancements in the study of microplastics in wastewater, their origins, behaviour in aquatic and terrestrial environments, and their potential adverse impacts on various organisms such as aquatic and terrestrial animals, soil microbial communities, plants, and finally humans. The results showed that using wastewater for irrigation can lead to the presence of microplastics in terrestrial ecosystems and can facilitate the transmission of contaminants in both terrestrial and aquatic ecosystems by interacting with a wide range of pollutants. The findings also indicate that although there has been significant scientific investigation into marine microplastics, research on the prevalence of microplastic contamination in freshwater and terrestrial environments is comparatively limited and requires greater attention for a better understanding of the fate, transport, and consequences of microplastics in relation to water, soil qualities, polymer composition, forms, and various types of land use.
... Another study highlighted that microplastics can produce an oxidative burst in tested plants, supporting those plants exposed to microplastics undergo nutrient deficiency as well as oxidative stress (Pignattelli et al. 2020). Godoy et al. (2019) found that plants exposed to metals absorbed lead, chromium, and zinc on microplastics. The results also indicated that dissolved organic matter plays a major role in the metal absorption on microplastics (Godoy et al. 2019). ...
... Godoy et al. (2019) found that plants exposed to metals absorbed lead, chromium, and zinc on microplastics. The results also indicated that dissolved organic matter plays a major role in the metal absorption on microplastics (Godoy et al. 2019). Biofilms are also ubiquitous in water, wherein microbes can attach to the hydrophobic surface and form the extracellular polymeric substance (EPS) that matures the biofilm. ...
... This accumulation means that MPs can increase the mobility of contaminants, making them harmful when ingested by organisms in the niche in which they settle [40]. By virtue of the bioaccumulation and biomagnification capacity of these contaminants in the food chain, they can impact humans who consume seafood products [13][14][15]38,39]. Figure 8 shows the SEM images of the microplastics with a size between <1 mm and 1 µm. ...
... This accumulation means that MPs can increase the mobility of contaminants, making them harmful when ingested by organisms in the niche in which they settle [40]. By virtue of the bioaccumulation and biomagnification capacity of these contaminants in the food chain, they can impact humans who consume seafood products [13][14][15]38,39]. ...
In this research, the abundance and physical and chemical characteristics of microplastics (MPs) in coastal sediments from three beaches of Puerto Vallarta in Mexico were investigated. The
objective of characterizing and finding MPs in sand is to generate information that is useful to manage macroplastic waste, prevent its additional generation, and thus reduce environmental pollution and
achieve sustainable development. The MPs were classified according to their physical characteristics such as color, size, and shape under a stereoscopic microscope, and their wear and surface were observed using a scanning electron microscope. The chemical composition of the most representative types of polymers were detected by Fourier-transform infrared spectroscopy. It can be observed that Los Muertos beach presents the highest number of MPs (97.5 particles/m2) followed by Boca de Tomates beach (69.75 particles/m2) and Oro beach (28.75 particles/m2). The differences found between the beaches are attributed to the tourist influx and proximity to the mouth of a river. In total, 37% of MPs were white, followed by 19% yellow, and 11% transparent. The shape distribution of microplastics of sizes < 5 mm and 1 mm was fragmented, the greatest abundance was microfibers, microfragments, and microfilms for MPs between <1 mm and 1 m, and these corresponded to polyester, polyethylene, cellophane, and polystyrene, respectively.
... This accumulation means that MPs can increase the mobility of contaminants, making them harmful when ingested by organisms in the niche in which they settle [40]. By virtue of the bioaccumulation and biomagnification capacity of these contaminants in the food chain, they can impact humans who consume seafood products [13][14][15]38,39]. Figure 8 shows the SEM images of the microplastics with a size between <1 mm and 1 µm. ...
... This accumulation means that MPs can increase the mobility of contaminants, making them harmful when ingested by organisms in the niche in which they settle [40]. By virtue of the bioaccumulation and biomagnification capacity of these contaminants in the food chain, they can impact humans who consume seafood products [13][14][15]38,39]. ...
In this research, the abundance and physical and chemical characteristics of microplastics (MPs) in coastal sediments from three beaches of Puerto Vallarta in Mexico were investigated. The objective of characterizing and finding MPs in sand is to generate information that is useful to manage macroplastic waste, prevent its additional generation, and thus reduce environmental pollution and achieve sustainable development. The MPs were classified according to their physical characteristics such as color, size, and shape under a stereoscopic microscope, and their wear and surface were observed using a scanning electron microscope. The chemical composition of the most representative types of polymers were detected by Fourier-transform infrared spectroscopy. It can be observed that Los Muertos beach presents the highest number of MPs (97.5 particles/m2) followed by Boca
de Tomates beach (69.75 particles/m2) and Oro beach (28.75 particles/m2). The differences found between the beaches are attributed to the tourist influx and proximity to the mouth of a river. In total, 37% of MPs were white, followed by 19% yellow, and 11% transparent. The shape distribution of microplastics of sizes < 5 mm and 1 mm was fragmented, the greatest abundance was microfibers, microfragments, and microfilms for MPs between <1 mm and 1 micrometer, and these corresponded to polyester, polyethylene, cellophane, and polystyrene, respectively.
... Studies revealed that different MPs can adsorb pollutants such as antibiotics , perfluorooctanoic sulphonamide (Wang et al. 2015), and heavy metals (Holmes et al. 2012;Li et al. 2019). The adsorption of heavy metals such as Cu, Cd, Cr, Pb, As, Zn, Ni, and Co on MPs has been investigated to understand potential capturing of metals, adsorption behavior, and mechanisms by MPs, specifically PE and PS (Dong et al. 2020;Godoy et al. 2019;Wang et al. 2020;Zhang et al. 2020;Zong et al. 2021). Godoy et al. (2019) suggested that chemical adsorption was the main adsorption mechanism due to better description of experimental data by the Langmuir model than by the Freundlich model for several types of MPs including PE, polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC). ...
... The adsorption of heavy metals such as Cu, Cd, Cr, Pb, As, Zn, Ni, and Co on MPs has been investigated to understand potential capturing of metals, adsorption behavior, and mechanisms by MPs, specifically PE and PS (Dong et al. 2020;Godoy et al. 2019;Wang et al. 2020;Zhang et al. 2020;Zong et al. 2021). Godoy et al. (2019) suggested that chemical adsorption was the main adsorption mechanism due to better description of experimental data by the Langmuir model than by the Freundlich model for several types of MPs including PE, polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC). ...
The adsorption process of inorganic arsenic (As) plays an important role in its mobility, bioavailability, and toxicity in the river environment. In this work, the adsorption of dissolved arsenite (As(III)) and arsenate (As(V)) by microplastics (MPs) pellets (polystyrene (PS) and low-density polyethylene (LDPE)), river sediment, and their mixture were investigated to assess the adsorption affinities and mechanism. The adsorption kinetics showed slow and mild rising zones from the natural behavior of the chemical adsorption. The results indicated that both MP characteristics and water properties played a significant role in the adsorption behavior of inorganic As species. The As adsorption equilibrium was modeled well by both Langmuir and Freundlich isotherms and partly fitted with the Sips model suggesting that both mono-layer and multi-layer adsorption occurred during adsorption The spontaneous adsorption process for both As(III) and As(V) was evidenced by the adsorption thermodynamics. The maximum adsorption capacities of As(III) and As(V) reached 143.3 mg/kg and 109.8 mg/kg on PS in deionized water, which were higher than those on sediment-PS mixture (119.3 mg/kg, 99.2 mg/kg), which were all lower than on sediment alone (263.3 mg/kg, 398.7 mg/kg). The Fourier transform infrared spectroscopy analysis identified that As(III) and As(V) interaction with sediment surface functional groups was the main adsorption mechanism from surface complexation and coordination. Two functional groups of polystyrene (-NH2, -OH) were mainly involved in the adsorption of inorganic As species on PS, while -COO- and -OH functional groups contributed to the adsorption mechanism of inorganic As species on LDPE. The findings provide valuable insight on the adsorption behavior and mechanisms of As(III) and As(V) in river systems in the presence of MPs particles. Both PS and LDPE were shown to be less effective than river sediment in the adsorption of As species from water, which provides a different perspective in understanding the scale of MPs impact in pollutant transport in the aquatic environment.
Graphical Abstract
... Regarding the adsorption of heavy metals and the chemical composition of MPs, Godoy et al. 53 analyzed the adsorption of Cd, Co, Cr, Cu, Ni, Pb and Zn by MPs of five different polymers (PE, PET, PP, PS and PVC), in Milli-Q water, seawater, wastewater and irrigation water. The results of the kinetic tests (carried out in Milli-Q water) showed that PE and PVC had higher sorption affinity toward metals (significant adsorption of Pb, Cr and Zn), with the order of adsorption being PE > PVC > PS > PP > PET. ...
... 10 Based on the results of the study, the adsorption of metals in MPs-metal interactions is not determined by a single factor but by the combination of several factors. 53 Through a laboratory test using microcosms with domestic wastewater, Zhao et al. 56 analyzed the individual and synergistic effects of Cu and Zn, and the antibiotics tetracycline (TC) and ampicillin (AMP) on microbial communities and resistance genes in PVC MPs, after exposure of 28 and 84 days. The main results showed that the individual presence of Zn, TC and AMP inhibited the growth of bacteria for a short period of time (28 days). ...
... In other studies, it was found that pristine PS with surface area < 0.001 m 2 /g able to sorb 0.008 mg/g Cu (Yang et al., 2019b). Other studies indicated that PS with an area of 3.2 m 2 /g was able to sorb 0.81 mg/g Co, 0.47 mg/g Cr and 0.36 mg/g Cu (Godoy et al., 2019). Studies with aged polymers show, for example, that aged, beached pellets accumulate heavy metals to a much greater extent than virgin pellets (Holmes et al., 2012). ...
Rhamnolipids are biosurfactants produced by bacteria belonging to the Pseudomonas genus. They are discussed to complex heavy metal cations stronger than cations of Fe, Ca, Mg. It is therefore suggested to employ rhamnolipids in phytoextraction where their addition to soil should result in preferential complexation of heavy metals that can be taken up by plants, thus enabling rapid and ecological clean-up of contaminated soil. In order to test this concept, we evaluated the rhamnolipid-mediated phytoextraction of heavy metal from soil collected from the vicinity of a copper smelter. The following aspects were investigated: i) selectivity of rhamnolipids towards Cu, Zn, Pb, Cd and Fe during soil washing; ii) phytoextraction efficiency of each ion with respect to the effective concentration of rhamnolipids; iii) possible phytotoxic effects; iv) effect of micro-sized polystyrene amendment. The experiments evaluated soil washing efficiency, BCR (Community Bureau of Reference) sequential extraction to determine the impact of rhamnolipids on the mobility of metal ions, phytoextraction with maize (Zea mays L.) and phytotoxic effects based on dry matter, chlorophyll fluorescence and content. The obtained results indicated that rhamnolipids lack desired selectivity towards heavy metal ions as Fe was complexed more efficiently by 80 % of the available rhamnolipids compared to priority pollutants like Zn, Cu, Pb, which were complexed by only 20 % of the tested rhamnolipids. With increased concentration of rhamnolipids, the soil washing efficiency increased and shifted in favour of Fe, reaching values of approx. 469 mg for Fe and only 118 mg in total of all tested heavy metals. Phytoextraction also favoured the accumulation of Fe, while Cd was not removed from the soil even at the highest applied rhamnolipid concentrations. Considering the selectivity of rhamnolipids and the costs associated with their production, our results suggest the need to search for other alternative (bio)surfactants with better selectivity and lower price.
... Thus, it is clear that chemical factors, such as water pH and salinity can increase or decrease metal adsorption. Godoy et al. (2019) in a field and laboratory study, acquired samples of different polymers and compared adsorption dynamics in different water samples, namely, ultra purified water, water collected from the Mediterranean Sea off the coast of Granada (Spain), water collected from an urban wastewater treatment plant in Granada (Spain) and irrigation water from the fertile plain of Granada (Spain). They found that the organic matter present on the microplastic increased lead and chromium adsorption, but that water pH altered these dynamics. ...
The production and disposal of plastic material has increased exponentially in recent decades. As a result, microplastics resulting from plastic degradation processes are now present in all environmental compartments, in particular, aquatic ecosystems. These microparticles can interact with different chemical pollutants, representing a significant risk to living organisms. In this context, the present study aimed to assess microplastics as chemical pollutant vectors in aquatic ecosystems, evaluating adsorption processes between these particles and both organic and inorganic pollutants. To this end, a scienciometric review was carried out, retrieving a total of 56 scientific articles. The retrieved studies indicate microplastic particles are capable of associating with different environmental chemical contaminants and that interactions depends on abiotic factors such as pH, salinity, light and temperature, the type of polymeric material and its aging characteristics and, finally, the organic matter adhered to the particle. Further studies on this topic are required to understand potential deleterious effects on aquatic biota due to microplastic-adsorbed chemical pollutants and establish measures capable of reducing and controlling these pollutants.
... Likewise, water physicochemical conditions (e.g., pH, salinity, temperature, redox potential, suspended solids and dissolved organic matter) affect the sorption and desorption processes. 10,[34][35][36][37] Given the complex framework governing the sorption-desorption processes, unveiling the consequences for the ecosystem is challenging. 35,38 The analysis of metals on plastic samples collected from environmental matrices can represent an initial step to assess the relevance of this interaction in environmental settings and to help in assessing the environmental risk posed by metalcontaining additives leaching from aged plastics, as well as by the metals adsorbed on MPs from the environment. ...
Understanding plastic–metal interactions is paramount to unveil the ecological risks of plastic pollution. Besides including a (variable) amount of metal-containing additives, plastic objects can adsorb metals on their surface in the environment. This work aims at measuring and assessing the possible origin of metals in environmental plastics deposited along the shores of Lake Como (Italy). Samples were characterized through Fourier-transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and water contact angle. Then, the total metal load was analysed by acid digestion. Surface extraction with nitric acid was also performed to detect labile metals and a three-step extraction scheme enabled the determination of physisorbed, carbonate-bonded and organic matter-bonded metals, respectively. Eighteen metals (Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Ag, Cd, Sn, Ba, Pb and U) were analysed in total. Newly produced plastic items were also analysed as a reference. Our findings revealed that environmental samples retained a higher concentration of metals compared to virgin ones, especially in the loosely bonded acid-extractable fractions, indicating their potential bioavailability. The source of metals on plastics was extremely variable: some metals were predominantly sorbed from the environment (e.g., Mn and Pb), and others were mainly leached from the plastic matrix (Ba, Cu and Ti) or had a mixed origin (Zn, Fe, Sn, Sr and Al). This work shed light on the changes in bioavailability of metals induced by plastic environmental ageing, set baseline values for a freshwater site, and provided insights into the potential bioavailability exerted by metals associated with plastic litter.
... Many waste plastics are discharged into the environment, where they further weather and decompose into microplastic particles (MPs), posing ecological risks to marine ecosystems (Bringer et al., 2020;Xia et al., 2020). Furthermore, MPs acting as vectors may influence the durability, mobility, bioavailability and toxicity of various coexisting contaminants (Bradney et al., 2019;Godoy et al., 2019;Selvam et al., 2020;Lin et al., 2021;Wang et al., 2021), including heavy metals (such as Pb, Cd, As, and Cu) (Mao et al., 2020) and organic contaminants (such as per-and polyfluorinated substances, pharmaceuticals, endocrine, and personal care products) Barhoumi et al., 2022;Qiu et al., 2023). This "Trojan horse" effect increases the ecological risk of MPs and coexisting contaminants. ...
... It was also deduced that the increased adsorption of metals onto MP is mostly due to the presence of organic matter. 81 A comprehensive analysis was also conducted regarding the changes occurring in PA, PE, and PS MP as they pass through the wastewater pipeline, grit chambers, and biological aeration tanks. In general, the research revealed an increased adsorption capacity of MP for cadmium (Cd) following their journey through the wastewater pipeline and biological aeration tanks, attributable to the physicochemical alterations experienced by the MP during this process. ...
Microplastics (MP) are commonly present in our daily life. Reported studies on MP pollution revealed that wastewater treatment plants (WWTPs) serve as pathways for MP to enter terrestrial and aquatic ecosystems, causing adverse effects on the quality of water bodies, aquatic life, and even contamination of soil and groundwater. In WWTPs, variable MP removal efficiencies from liquid streams have been reported. However, many MP particles are still discharged into natural water bodies. Concomitantly, the retention of MP in sewage sludge is reported, and thus, understanding MP fate in WWTPs is of great significance towards MP management. This review discusses the most recent research focused on the abundance and removal of MP in WWTPs, the main methodologies applied to MP sampling, extraction, identification, and quantification in WWTPs, and the current knowledge on MP as transport vectors for other (micro)pollutants. The transfer of MP from wastewater to sludge raises environmental concerns, and efforts to optimize the value of sludge within a circular economy are essential. The potential of bioaugmentation strategies with plastic-degrading microorganisms to enhance MP removal emphasizes the importance of ongoing research, although it is still in its early stages. It is essential to improve and standardize methods for MP sampling, extraction, visual inspection, and chemical quantification in wastewater and sludge samples. The necessity for further investigation into MP interactions with other environmental (micro)pollutants and their potential impact on human health is also highlighted.
... Inflammatory responses, gut microbial dysbiosis, impaired hepatic lipid metabolism, and dysfunction of the intestinal barrier [34][35][36] have all been linked to exposure to microplastics. Moreover, human tissues can absorb microplastics, where microplastics can induce oxidative stress [37], hinder the immune system [38], and serve as a vector for environmental contaminants [39][40][41][42][43]; the latter may increase toxic repercussions. ...
Microplastics (MPs) are prevalent in our environment, being present in the air we breathe and in the food we consume. Due to the widespread use of plastic materials in everyday life, the amount of microplastics being released into the biosphere has become increasingly apparent in recent years. This study provides the first documentation of the presence of microplastics in Chinese baijiu, a popular alcoholic beverage in China, bottled in plastic. It is essential to note the significance of this discovery and potential implications for human health. Analysis of samples collected from the Chinese market showed the presence of microplastics in all six Chinese baijiu brands tested. Concentrations ranged from 172 MPs/500 mL to 944 MPs/500 mL with an average concentration of 436 MPs/500 mL. Cellulose and PA accounted for 70.4% and 17.8% of all microplastics detected, respectively. These were the most commonly detected types. Other types of microplastics were also found, including PET, PP, PVC, and PE. PET accounted for 2.7%, PP for 2.2%, PVC for 1.2%, and PE for 0.1% of all microplastics. The possible sources of contamination include raw materials, ambient air, and equipment and vessels that shed microplastics. Therefore, this study emphasizes the requirement for further research to mitigate the potential hazards associated with human exposure to microplastics. Additionally, it presents significant findings on the presence of microplastics in Chinese baijiu sold in plastic bottles.
... These polymers have a range of additives and chemical that contaminate the environment throughout their persistent life. Each of the identified polymer type is reported to be absorbent of various contaminants including heavy metals [63][64][65][66][67]. These recorded types are also reported to adsorb a wide range of pesticides and may contaminate the agricultural ecosystems synergistically [59,[68][69][70][71]. ...
Microplastics (MPs) contaminate every conceivable terrestrial and aquatic environment including high peaks and deep marine trenches. Agricultural lands alone are expected to receive plastic up to 23 times more than ocean basins. In this study, soil samples were collected from peri-urban agricultural lands of Lahore on four sides including Kala Shah Kaku (KSK), Punjab University (PU), Dera Gujran (DG), and Sagian (SG). National Oceanic and Atmospheric Administration (NOAA) protocol was used for MPs extraction and analysis. Extracted MPs were analyzed under microscope at 40X magnification and their composition was analyzed using Fourier Transform Infrared (FTIR) spectroscopy. A considerable concentration of MPs was recorded at all sites. The highest contamination was found at SG with 876 ±194 MPs/kg of soil, and the lowest contamination was recorded at PU with 672 ±235 MPs/kg of soil. However, these differences among the sites were not statistically significant ( p = 0.29). The overall predominant shape of MPs was fibers (613±71, 79.73%) followed by sheets (125±55, 16.28%), fragments (30±5, 3.9%) and foam particles (1±2, .09%). The differences in the distribution of MPs in various types were statistically significant ( p = 0), while differences between sites were insignificant ( p = 0.13). About 95% of MPs were less than 2 mm and 85% were less than 1 mm size. The distribution of MPs in various sizes ( p = 0) and differences of this distribution between sites ( p = 0.037) were both statistically significant. A good diversity of nine colored MPs was recorded, however majority of the MPs were transparent (89.57%). Six polymer including Polyethylene (PE), Polyethylene terephthalate (PET), Polypropylene (PP), Polystyrene (PS), Polycarbonate (PC), and Polyvinyl Chloride (PVC) were identified by FTIR. The current levels of MPs pollution are higher than in many other parts of the world. Composition of MPs (types, colors, sizes, and polymer types) indicates the diversity of their sources and their possible implications on agricultural ecosystem.
... In addition to being a source of pollution themselves, MPs also function as carriers or vectors of other pollutants in the environment (Avio et al., 2017;Tang, 2021). These small plastic particles have the capability to adsorb and accumulate various toxic substances, including persistent organic pollutants (POPs) (Tang, 2021), heavy metals (Godoy et al., 2019), and other chemicals (Andrady, 2017;Auta et al., 2018;Rochman et al., 2014;Wang et al., 2022). The small size and large surface area of MPs make them efficient in adsorbing pollutants present in the surrounding environment. ...
... Polypropylene, among the other polymers, showed a higher capacity for adsorption [125]. Godoy et al. studied the adsorption of several heavy metals (Cd, Co, Cu, Cr, Ni, Pb, and Zn) on different types of microplastics [126]. They found that the polyethylene and polyvinyl chloride showed a higher ability to adsorb Pb, Cr, and Zn, while the low adsorption capacity was related to polyethylene terephthalate. ...
Heavy metal contamination in wastewater is a significant concern for human health and the environment, prompting increased efforts to develop efficient and sustainable removal methods. Despite significant efforts in the last few decades, further research initiatives remain vital to comprehensively address the long-term performance and practical scalability of various adsorption methods and adsorbents for heavy metal remediation. This article aims to provide an overview of the mechanisms, kinetics, and applications of diverse adsorbents in remediating heavy metal-contaminated effluents. Physical and chemical processes, including ion exchange, complexation, electrostatic attraction, and surface precipitation, play essential roles in heavy metal adsorption. The kinetics of adsorption, influenced by factors such as contact time, temperature, and concentration, directly impact the rate and effectiveness of metal removal. This review presents an exhaustive analysis of the various adsorbents, categorized as activated carbon, biological adsorbents, agricultural waste-based materials, and nanomaterials, which possess distinct advantages and disadvantages that are linked to their surface area, porosity, surface chemistry, and metal ion concentration. To overcome challenges posed by heavy metal contamination, additional research is necessary to optimize adsorbent performance, explore novel materials, and devise cost-effective and sustainable solutions. This comprehensive overview of adsorption mechanisms, kinetics, and diverse adsorbents lays the foundation for further research and innovation in designing optimized adsorption systems and discovering new materials for sustainable heavy metal remediation in wastewater.
... The Langmuir, Freundlich, and Temkin models were used to characterize the isothermal adsorption processes of TYL and TC onto microplastics (Godoy et al., 2019;. The Langmuir, Freundlich, and Temkin isothermal adsorption equations are shown in Eqs. ...
Microplastic pollution is becoming one of the most severe threats to the entire earth surface ecosystem; moreover, it has the potential to act as a carrier for other chemical pollutants, introducing these pollutants in diverse environments. To evaluate this threat, this study investigated the adsorption of two antibiotics, tylosin (TYL) and tetracycline (TC), onto three common environmental microplastics, polyethylene (PE), polystyrene (PS), and polyvinyl chloride (PVC), through batch adsorption experiments. Overall, the Freundlich model fitted the isothermal adsorption well, which indicated inhomogeneous distribution of adsorption sites involved in the adsorption. The fitted parameters indicated that the adsorption of TYL and TC onto PVC was highest relative to that onto the other two microplastics, which was attributed to the differences in functional groups and crystallinity of polymers. The adsorption efficiency decreased with increasing microplastic concentration. Owing to the salting-out effect, the increase in salinity promoted TYL adsorption onto the microplastics; salinity had no significant effect on TC adsorption onto microplastics. The results suggest that microplastics can be carriers of antibiotics in the environment, for which the physicochemical properties of microplastics and antibiotics as well as environmental factors are crucial influencing factors. This study further clarifies the adsorption mechanisms of contaminants onto microplastics under different environmental conditions.
... Polyethylene and polypropylene appear as the most common polymer types, associated with packaging and single-use plastics, and are more abundant in surface water than in sediments. Microplastics can adsorb chemical pollutants such as metals or pharmaceuticals, and transfer them along the food chain, which represents an additional threat to marine life and requires consideration when assessing the risk of microplastic pollution (Patterson et al., 2022;Godoy et al., 2019). ...
Climate change and marine litter are inextricably linked, and their interaction manifests differently depending on the specific environmental and biological characteristics, and other human activities taking place. The negative impacts resulting from those synergistic interactions are threatening coastal and marine ecosystems and the many goods and services they provide. This is particularly pervasive in the coastal zone of the Indian subcontinent. India is already experiencing severe climate change impacts, which are projected to worsen in the future. At the same time, the country is gripped by a litter crisis that is overwhelming authorities and communities and hindering the country's sustainable development goals. The coastal environment and communities of the southern states of Kerala and Tamil Nadu are particularly vulnerable to the impacts of climate change. While these state governments and authorities are stepping up efforts to improve the management of their coastal zones, the scale and severity of these issues are mounting. Here we review the combined effects of climate change and marine litter pollution in Southern India, focusing on the Gulf of Mannar Reserve in Tamil Nadu and the Malabar Coast in Kerala. Finally, we discuss effective management options that could help improve resilience and sustainability.
... As indicated by their results, the descending fast and slow order of adsorption of metal ions to polyamide-6 MPs is expressed as Pb>Cu>Cd. V. Godoy [12] has suggested that PE, PP, PS, and PVC are capable of quickly adsorbing Cr, Cu, Co, and Pb since the roughness and irregularity of the microplastic surface provide considerable adsorption sites for heavy metal ions. The adsorption of heavy metals by the MPs is affected by a considerable number of factors. ...
... 31 There is also geogenic heavy metal contamination in stormwater, which is primarily generated from weathering of soil parent material and rocks. 32 In stormwater, metals are present in dissolved form (<0.45 μm) as well as truly dissolved form (<0.02 μm), both of these types are highly bioavailable as well as harmful to organisms if the concentrations are significant. 33 Organic contaminants can also be found in stormwater, pesticides, herbicides, and pharmaceuticals and personal care products (PPCPs) from agricultural and residential areas, respectively. ...
The main aim of the Blue-Green City concept is the reduction of the adverse impacts of stormwater by recreating the natural water cycle with the aid of green infrastructure in...
... In addition, all tested heavy metals except Cr in the Xintong soil significantly decreased in PVC MPs treatments. There are two possible reasons: firstly, PVC MPs have an adsorption ability for heavy metals in the soil [41], which can be attributed to their rubber-like properties to include larger diffusivity [44,45], and the presence of polar groups containing chlorine that have good adsorption performance for heavy metal ions [40]. Moreover, after aging, the surface of MPs becomes cracked or uneven, increasing the specific surface area and adsorption capacity for heavy metals [13,3,49]. ...
Microplastics (MPs) have emerged as widely existing global environmental concerns in terrestrial ecosystems. However, the mechanisms that how MPs are affecting soil microbes and their metagenomic functioning is currently uncertain. Herein, we investigated the response mechanisms of bacterial and fungal communities as well as the metagenomic functions to the addition of MPs in two soils with distinct pH and heavy metals. In this study, the acidic soil (Xintong) and the neutral soil (Huanshan) contaminated by heavy metals were incubated with Polyvinyl Chloride (PVC) MPs at ratios of 2.5% and 5% on 60 and 120 days. We aimed to evaluate the responding, assembly, and interactions of the metagenomic taxonomy and function. Results showed that only in the acidic soil, PVC MPs significantly increased soil pH and decreased CaCl2-extractable heavy metals, and also reduced bacterial alpha diversity and interaction networks. The relative proportions of Proteobacteria and Bacteroidota in bacteria, and Mortierellomycota in fungi, were increased, but Chloroflexi and Acidobacteriota in bacteria, Ascomycota and Basidiomycota in fungi, were significantly decreased by PVC MPs. Metagenomic functions related to C cycling were repressed but the nutrient cycles were enriched with PVC MPs. In conclusion, our study suggests that the addition of PVC MPs could shift soil microbial community and metagenomic functioning, as well as increasing soil pH and reduced heavy metal availability.
... These residues may be considered "emerging contaminants" because of their toxicity, whose effects and presence in the environment are still unknown and susceptible to ingestion by living organisms (Castro et al., 2016;Morais et al., 2020;Nan et al., 2020). Intake brings several risks to living beings because microplastic can adsorb organic pollutants and heavy metals -especially PE, PP, PS, and PVC (Gallo et al., 2018;Godoy et al., 2019) -and hence serve as transport vehicles (Auta et al., 2017), causing bioaccumulation in body tissues and/or body fluids, causing effects of intoxication (Anbumani and Kakkar, 2018). ...
Plastic particles of microscopic scale are present in the aquatic environment, especially at lower trophic trophic levels where the number of microplastics (MPs) ingested per gram wet weight is greater than in higher trophic levels. The presence of microplastics (MPs) in water bodies is caused by anthropogenic activities and waste disposal negligence such as disposal waste, disposal waters, industry, agriculture, fishing, ship traffic, and environmental factors, which have been monitored in remote locations by bioindicators and tracking tools such as numerical modeling and life cycle inventories. Our review process shows that more studies are conducted in the northern hemisphere, and most of the analyzed MPs are either Polyethylene (PE), Polypropylene (PP), or Polystyrene (PS). Moreover, several papers report potential adverse effects on the biota can be disturbances in feeding, mobility, and reproduction that may cause lethal or sub-lethal consequences. Thus, to reduce the environmental impact and the effects on species exposed to microplastic particles we suggest research that helps in the establishment of limits of occurrence of these materials according to their physical-chemical properties, uniform measuring standards, and their toxicity to the environment to promote legislation for the control and mitigation this contamination.
The analysis of micro- and nanoplastics (MNPs) in the environment is a critical objective due to their ubiquitous presence in natural habitats, as well as their occurrence in various food, beverage, and organism matrices. MNPs pose significant concerns due to their direct toxicological effects and their potential to serve as carriers for hazardous organic/inorganic contaminants and pathogens, thereby posing risks to both human health and ecosystem integrity. Understanding the fate of MNPs within wastewater treatment plants (WWTPs) holds paramount importance, as these facilities can be significant sources of MNP emissions. Additionally, during wastewater purification processes, MNPs can accumulate contaminants and pathogens, potentially transferring them into receiving water bodies. Hence, establishing a robust analytical framework encompassing sampling, extraction, and instrumental analysis is indispensable for monitoring MNP pollution and assessing associated risks. This comprehensive review critically evaluates the strengths and limitations of commonly employed methods for studying MNPs in wastewater, sludge, and analogous environmental samples. Furthermore, this paper proposes potential solutions to address identified methodological shortcomings. Lastly, a dedicated section investigates the association of plastic particles with chemicals and pathogens, alongside the analytical techniques employed to study such interactions. The insights generated from this work can be valuable reference material for both the scientific research community and environmental monitoring and management authorities.
Graphical Abstract
Plastic has been known as an artificial polymer whereas environmental microplastics become a global concern. Microplastics are reported to cause immunotoxicity in humans through gut deposition and entering the bloodstream. This study is a comprehensive indication of the recent research on microplastic toxicity in the gastrointestinal system. We performed bibliographic analysis using VOS viewer software and analyzed the data received on microplastics and their impact on gut health which has grown exponentially since 2016. Recent findings also support microplastic toxicity in combination with heavy metals. The smaller particle size and other factors enhanced the adsorption ability of environmental contamination such as heavy metals on microplastic which increased their bioaccumulation. Such toxic complexes of heavy metals and microplastics are a concern to natural ecosystems and environmental biologists. Few reports also demonstrated the biofilm formation on microplastic surfaces which might cause greater environmental as well as human health risks. Notably, terms of determining the microplastics in human tissues through several analytical techniques are still limited to some extent. Future research should be focused on the quantification of microplastics in human tissues, the combined effect of microplastics with other contaminants, and their effects on pre-existing diseases. This study boosts understanding of the potential impacts of microplastic and nanoplastic toxicity in the human gastrointestinal system.
Microplastics (MPs) and heavy metals are significant pollutants in the marine environment, necessitating effective remediation strategies to prevent their release into the sea through sewage and industrial effluent. This comprehensive review explores the current understanding of the co-exposure of MPs and heavy metal–enriched MPs, highlighting the need for effective remediation methods. Various mechanisms, including surface ion complexation, hydrogen bonding, and electrostatic forces, contribute to the adsorption of heavy metals onto MPs, with factors like surface area and environmental exposure duration playing crucial roles. Additionally, biofilm formation on MPs alters their chemical properties, influencing metal adsorption behaviors. Different thermodynamic models are used to explain the adsorption mechanisms of heavy metals on MPs. The adsorption process is influenced by various factors, including the morphological characteristics of MPs, their adsorption capacity, and environmental conditions. Additionally, the desorption of heavy metals from MPs has implications for their bioavailability and poses risks to marine organisms, emphasizing the importance of source reduction and remedial measures. Hybrid approaches that combine both conventional and modern technologies show promise for the efficient removal of MPs and heavy metals from marine environments. This review identifies critical gaps in existing research that should be addressed in future studies including standardized sampling methods to ensure accurate data, further investigation into the specific interactions between MPs and metals, and the development of hybrid technologies at an industrial scale. Overall, this review sheds light on the adsorption and desorption mechanisms of heavy metal–enriched MPs, underscoring the necessity of implementing effective remediation strategies.
Graphical Abstract
The entry of micro-and nanoplastics (MNPs) into the human body is inevitable. They enter blood circulation through ingestion, inhalation, and dermal contact by crossing the gut-lung-skin barrier (the epithelium of the digestive tract, the respiratory tract, and the cutaneous layer). There are many reports on their toxicities to organs and tissues. This paper presents the first thorough assessment of MNP-driven bloodstream toxicity and the mechanism of toxicity from the viewpoint of both MNP and environmental co-pollutant complexes. Toxic impacts include plasma protein denaturation, hemolysis, reduced immunity, thrombosis, blood coagulation, and vascular endothelial damage, among others, which can lead to life-threatening diseases. Protein corona formation, oxidative stress, cytokine alterations, inflammation, and cyto-and genotoxicity are the key mechanisms involved in toxicity. MNPs change the secondary structure of plasma proteins, thereby preventing their transport functions (for nutrients, drugs, oxygen, etc.). MNPs inhibit erythropoiesis by influencing hematopoietic stem cell proliferation and differentiation. They cause red blood cell and platelet aggregation, as well as increased adherence to endothelial cells, which can lead to thrombosis and cardiovascular disease. White blood cells and immune cells phagocytose MNPs, provoking inflammation. However, research gaps still exist, including gaps regarding the combined toxicity of MNPs and co-pollutants, toxicological studies in human models, advanced methodologies for toxicity analysis, bioaccumulation studies, inflammation and immunological responses, dose-response relationships of MNPs, and the effect of different physiochemical characteristics of MNPs. Furthermore, most studies have analyzed toxicity using prepared MNPs; hence,
The objective of this study was to assess the combined impact of environmental microplastic pollution and biological invasion which represent critical global eco-environmental challenges. The invasion of Solidago canadensis L. and soil microplastic contamination in the agroecosystem pose severe hazards to soil and plant ecology and human health. Oryza sativa L. (rice) was examined after individual and combined exposure to Solidago canadensis L. invasion (SI) and soil polyethylene microplastic contamination (MPc). Comparing the individual and combination treatments to the control, leaf biomass decreased, with varying changes in carbon, nitrogen, and phosphorus. Antioxidant enzyme activity and reactive oxygen species levels were significantly reduced following SI exposure and increased following the combined treatment (SI × MP). In contrast, ascorbate peroxidase and catalase activities were reduced after the combined treatment. Due to the confluence of various abiotic stressors, the combined treatment had a higher impact on leaf metabolites than the singular SI and MPc treatments. However, in comparison, the combined treatment significantly influenced the metabolic profile. In conclusion, the interaction between SI and MPc resulted in significant metabolic alterations. These changes were characterized by shifts in metabolite pools influenced by antioxidant enzyme activities and nutrient content, ultimately enhancing defense mechanisms within rice crops. Consequently, these stressors threaten the food safety, sustainability, and agricultural output of crops. The co-exposure of invasive plants and microplastics sheds light on the bio-ecological risks associated with microplastics in staple foods and offers valuable insights into the phytotoxicity of invasive plants in the presence of polyethylene microplastics. J o u r n a l P r e-p r o o f Journal Pre-proof 3 Environmental implication Invasive plants and the buildup of microplastics in agricultural soil can interact to create a novel type of soil pollution that has unpredictable effects on crops and jeopardizes human health and global food security. This work offers an understanding of how invasive alien plants and microplastic contamination affect plant performance and the metabolomic profile of rice crops, both individually and in combination. The present findings are significant for understanding the joint exposure impacts of invasive alien plants and microplastic contamination on crop plants and soil on farmland, as well as their implications for sustainable agriculture and human well-being. J o u r n a l P r e-p r o o f Journal Pre-proof 4
Microplastic Pollution: Causes, Effects, and Control sheds light on the causes, effects, and control of microplastic pollution, providing valuable insights into the tools and techniques for analysis, the impact on ecosystems, and the potential risks to human well-being. The editors focus on the urgency of addressing this global environmental challenge through collaborative efforts and sustainable solutions. This reference features 10 edited chapters covering multiple aspects of microplastic pollution. The book introduces the reader to various tools and techniques used to analyze microplastic pollution in both aquatic and terrestrial ecosystems. It then examines the sources, pathways, and levels of microplastic contamination in the environment and explains how to evaluate the potential health risks for the nearby communities. The impact of microplastic on flora and fauna is presented in one chapter. To emphasize the importance of assessing microplastic contamination, the editors present a case study conducted in Thoothukudi, South India, to explore the implications of microplastic pollution on human health. The book also provides information on solutions to microplastic pollution including the use of bioplastics and removal techniques.
Microplastic Pollution: Causes, Effects, and Control equips readers with a complete understanding of the global challenge of microplastics, fostering awareness and encouraging further research and action to protect our ecosystems and human health from their detrimental impact. It is an ideal handbook for environmental science researchers and students who need to understand microplastic pollution and plan environmental impact assessments for academic research and professional projects.
Key Features
- Comprehensive coverage of microplastic pollution with 10 structured chapters
- Informs readers about important parameters to understand and measure the impact of microplastics on local fauna, flora and the surrounding environment
- Covers evaluation and remediation of microplastics in both terrestrial and marine environments
- Includes references for advanced readers
- Includes a case study on the effect of microplastics in Thoothukudi, South India
Copper nanoparticles (CuNPs) and microplastics (MPs) are two emerging contaminants of freshwater systems. Despite their co-occurrence in many water bodies, the combined effects of CuNPs and MPs on aquatic organisms are not well-investigated. In this study, primary cultures of rainbow trout hepatocytes were exposed to dissolved Cu, CuNPs, MPs, or a combination of MPs and CuNPs for 48 h, and the transcript abundances of oxidative stress-related genes were investigated. Exposure to CuNPs or dissolved Cu resulted in a significant increase in the transcript abundances of two antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD). Exposure to CuNPs also led to an upregulation in the expression of Na⁺/K⁺ ATPase alpha 1 subunit (ATP1A1). Microplastics alone or in combination with CuNPs did not have a significant effect on abundances of the target gene transcripts. Overall, our findings suggested acute exposure to CuNPs or dissolved ions may induce oxidative stress in hepatocytes, and the Cu-induced effect on target gene transcripts was not associated with MPs.
Over the past 50 years, the emergence of plastic waste as one of the most urgent environmental problems in the world has given rise to several proposals to address the rising levels of contaminants associated with plastic debris. Worldwide plastic production has increased significantly over the last 70 years, reaching a record high of 359 million tonnes in 2020. China is currently the world's largest plastic producer, with a share of 17.5%. Of the total marine waste, microplastics account for 75%, while land-based pollution accounts for responsible for 80-90%, and ocean-based pollution 10-20% only in overall pollution problems. Even at small dosages (10 μg/mL), microplastics have been found to cause toxic effects on human and animal health. This review examines the sources of microplastic contamination, the prevalent reaches of microplastics, their impacts, and the remediation methods for microplastic contamination. This review explains the relationship between the community composition and the presence of microplastic particulate matter in aquatic ecosystems. The interaction between microplastics and emerging pollutants, including heavy metals, has been linked to enhanced toxicity. The review article provided a comprehensive overview of microplastic, including its fate, environmental toxicity, and possible remediation strategies. The results of our study are of great value as they illustrate a current perspective and provide an in-depth analysis of the current status of microplastics in development, their test requirements, and remediation technologies suitable for various environments.
Plastic wastes deposited in landfills eventually break down and degrade into microplastics by physical, chemical, and biological forces. Though microplastics in leachate pose significant threats to the environment, the leachate generated from landfills has not received much attention as a possible source of environmental microplastics. A descriptive and systematic investigationof the global distribution of microplastics in landfill leachate does not exist to date. Therefore, this attempt is to provide a concise scientometric review of the studies on the presence of microplastics in landfill leachate. The present review revealed that the global trend in research on microplastics in leachate has increased exponentially after 2018 and China is the leading country. Different geographical regions have reported different microplastic abundances with the highest of 291.0 ± 91.0 items/L from a landfill in Shanghai. The use of novel sampling techniques to detect small microplastics (20-100 µm) has led to the high abundance of microplastics in landfill leachate in Shanghai. Due to its widespread usage, polyethylene is the most typically encountered polymer type in landfill leachate around the world. However, it is quite challengingto compare the results among studies due to the use of different size categories and extraction techniques. The removal of microplastics by the current leachate treatment facilities is still mostly unexplored, thus it is crucial to develop novel technologies to treat the microplastics in landfill leachate. Further investigations on the transport of microplastics in landfill leachate are urgently required to have a better understanding of potential human exposure and health implications.
Microplastics (MPs) have been found to be widely distributed in aquatic environments, where they will interact with toxic heavy metals and result in more serious adverse effects on the aquatic environments and organisms. However, after entering the aquatic environments, MPs are quickly covered by biofilms, which significantly modify MPs properties and relevant heavy metals adsorption-desorption characteristics In order to better understand the adsorption behavior of heavy metals on biofilm developed MPs (BMPs), we comprehensively reviewed representative studies in this area. First, we summarized the formation process of biofilms on MPs. Subsequently, we reviewed the current understanding on the influence of biofilm formation on the properties of MPs and discussed the metal adsorption-desorption characteristics of MPs affected by these changes. Finally, based on the systematic literature review, some future research needs and strategies were proposed to further understand the interactions between MPs and heavy metals.
Brazil maintains its position at the top of the global ranking of plastic producers, yet recycling efforts have been incipient. Recent data reveals an annual production of approximately 14 million tons of plastic waste, not accounting for the surge in the usage of plastic masks and related materials due to the COVID-19 pandemic. However, what remains largely unreported is that over half of post-consumer plastic packaging in Brazil is managed without any monitoring, and it remains unclear how this will contribute to the occurrence of plastic waste and microplastics in Brazilian freshwaters. This scenario requires the consideration of several other crucial factors. Studies have been carried out mainly in marine and estuarine waters, while data on freshwaters are lacking. Brazil has continental dimensions and the highest water availability on the planet, yet the demand for water is greatest in regions with medium to low supply. Many densely populated Brazilian urban areas face chronic flood problems, possess inadequate levels of wastewater treatment, and display inadequate solid waste management practices. Consequently, urban freshwater with tropical characteristics in Brazil presents an intriguing scenario and is complementary to the most commonly studied marine environments. In this study, we explore the nuances of pollution in Brazilian urban freshwater and discuss how various parameters, such as organic matter, suspended solids, temperature, and pH, among others, influence the behavior of microplastics and their interactions with organic and inorganic contaminants. Furthermore, we address how microplastic conditions, such as biofouling, the type of plastic, or degradation level, may impact their behavior. By analyzing how these conditions change, we propose priority themes for investigating the occurrence of microplastics in Brazilian urban freshwater systems under different degrees of human impact. Ultimately, this study aims to establish a network dedicated to standardized monitoring of microplastic pollution in Brazilian urban freshwaters.
Disposable surgical masks emerged as a solution to the increasing protection demands against fine/ultrafine particulate matter. It was prompted by the SARS-CoV-2 pandemic and the escalating levels of air pollution...
Increasing world plastic production generates million tonnes of waste. Flexible packaging bags specially suppose a challenge in mechanical recycling because of their singular properties. This research aims to provide a physical-chemical characterization of commercial polyethylene bags in order to facilitate a future improvement or adaptation of recycling processes to them. Firstly, properties such as dimensions and density were measured in regular and garbage bags samples purchased in different establishments of Granada (Spain). Then, a chemical classification in three groups (HDPE, LDPE, mixture) was achieved according to Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) tests. Finally, ash content was also determined.
The study of microplastic pollution involves multidisciplinary analyses on a large number of microplastics. Therefore, providing an overview of plastic pollution is time consuming and, despite high throughput analyses, remains a major challenge. The objective of this study is to propose a protocol to determine how many microplastics must be analyzed to give a representative view of the particle size distribution and chemical nature, and calculate the associated margin error. Based on microplastic data from Tara Mediterranean campaign, this approach is explained through different examples. In this particular case, the results show that only 3% of the collected microplastics need to be analyzed to give a precise view on the scale of the North West Mediterranean Basin (error <5%), and 17.7% to give an overview manta per manta (error <10%). This approach could be an important practical contribution to microplastic studies.
Plastic pollution represents a pervasive and increasing threat to marine ecosystems worldwide and there is a need to better understand the extent to which microplastics (<5 mm) are ingested by high trophic-level taxa, such as marine mammals. Here, we perform a comprehensive assessment by examining whole digestive tracts of 50 individuals from 10 species whilst operating strict contamination controls. Microplastics were ubiquitous with particles detected in every animal examined. The relatively low number per animal (mean = 5.5) suggests these particles are transitory. Stomachs, however, were found to contain a greater number than intestines, indicating a potential site of temporary retention. The majority of particles were fibres (84%) while the remaining 16% was fragments. Particles were mainly blue and black (42.5% and 26.4%) in colour and Nylon was the most prevalent (60%) polymer type. A possible relationship was found between the cause of death category and microplastic abundance, indicating that animals that died due to infectious diseases had a slightly higher number of particles than those that died of trauma and other drivers of mortality. It is not possible, however, to draw any firm conclusions on the potential biological significance of this observation and further research is required to better understand the potential chronic effects of microplastic exposure on animal health, particularly as marine mammals are widely considered important sentinels for the implications of pollution for the marine environment.
Microplastics are abundant and widespread in the marine environment. They are a contaminant of global environmental and economic concern. Due to their small size a wide range of marine species, including zooplankton can ingest them. Research has shown that microplastics are readily ingested by several zooplankton taxa, with associated negative impacts on biological processes. Zooplankton is a crucial food source for many secondary consumers, consequently this represents a route whereby microplastic could enter the food web and transfer up the trophic levels. In this review we aim to: 1) evaluate the current knowledge base regarding microplastic ingestion by zooplankton in both the laboratory and the field; and 2) summarise the factors which contribute to the bioavailability of microplastics to zooplankton. Current literature shows that microplastic ingestion has been recorded in 39 zooplankton species from 28 taxonomic orders including holo- and meroplanktonic species. The majority of studies occurred under laboratory conditions and negative effects were reported in ten studies (45%) demonstrating effects on feeding behaviour, growth, development, reproduction and lifespan. In contrast, three studies (14%) reported no negative effects from microplastic ingestion. Several physical and biological factors can influence the bioavailability of microplastics to zooplankton, such as size, shape, age and abundance. We identified that microplastics used in experiments are often different to those quantified in the marine environment, particularly in terms of concentration, shape, type and age. We therefore suggest that future research should include microplastics that are more representative of those found in the marine environment at relevant concentrations. Additionally, investigating the effects of microplastic ingestion on a broader range of zooplankton species and life stages, will help to answer key knowledge gaps regarding the effect of microplastic on recruitment, species populations and ultimately broader economic consequences such as impacts on shell- and finfish stocks.
ABSTRACT: Ingestion of microplastics by marine organisms is a common occurrence in marine ecosystems, but the experimental demonstration of the effects of ingested microplastics on marine organisms has only recently become an important subject of research. In this review, the ingestion of microplastics by marine organisms, its attendant potential consequences and specific hypothet- ical questions for further studies are discussed. The formation of heteroaggregates in the gut of prey organisms may delay microplastic clearance, potentially increasing the chances of microplas- tic trophic transfer to predators. Also, the survival and energetics of keystone species at lower trophic levels are negatively affected by ingestion of microplastics, thereby raising questions about the transfer of energy and nutrients to organisms at higher trophic levels. Further, since microplastics are able to adsorb and concentrate organic pollutants up to 1 million times more than the pollutant concentration in ambient waters, the ingestion of such small plastic fragments is, a probable route for the entrance and biomagnification of toxic chemicals in the marine food web. However, the equilibrium state between pollutant concentration in marine organisms and that of surrounding waters makes it unclear whether the ingestion of microplastics actually increases the pollutant load of organisms. Finally, microplastic ingestion can cause endocrine dis- orders in adult fish, which could result in neoplasia via epigenetic programming. Therefore, microplastic pollution may be a contributory cause of increased incidents of neoplasia in marine animals. The amount of microplastics in marine waters will steadily rise, and questions about their impact on marine ecosystems will linger.
The effects of microplastics (MP) on aquatic organisms are currently the subject of intense research. Here, we provide a critical perspective on published studies of MP ingestion by aquatic biota. We summarize the available research on MP presence, behaviour and effects on aquatic organisms monitored in the field and on laboratory studies of the ecotoxicological consequences of MP ingestion. We consider MP polymer type, shape, size as well as group of organisms studied and type of effect reported. Specifically, we evaluate whether or not the available laboratory studies of MP are representative of the types of MPs found in the environment and whether or not they have reported on relevant groups or organisms. Analysis of the available data revealed that 1) despite their widespread detection in field-based studies, polypropylene, polyester and polyamide particles were under-represented in laboratory studies; 2) fibres and fragments (800–1600 μm) are the most common form of MPs reported in animals collected from the field; 3) to date, most studies have been conducted on fish; knowledge is needed about the effects of MPs on other groups of organisms, especially invertebrates. Furthermore, there are significant mismatches between the types of MP most commonly found in the environment or reported in field studies and those used in laboratory experiments. Finally, there is an overarching need to understand the mechanism of action and ecotoxicological effects of environmentally relevant concentrations of MPs on aquatic organism health.
Persistent plastics, with an estimated lifetime for degradation of hundreds of years in marine conditions, can break up into micro- and nanoplastics over shorter timescales, thus facilitating their uptake by marine biota throughout the food chain. These polymers may contain chemical additives and contaminants, including some known endocrine disruptors that may be harmful at extremely low concentrations for marine biota, thus posing potential risks to marine ecosystems, biodiversity and food availability. Although there is still need to carry out focused scientific research to fill the knowledge gaps about the impacts of plastic litter in the marine environment (Wagner et al. in Environ Sci Eur 26:9, 2014), the food chain and human health, existing scientific evidence and concerns are already sufficient to support actions by the scientific, industry, policy and civil society communities to curb the ongoing flow of plastics and the toxic chemicals they contain into the marine environment. Without immediate strong preventive measures, the environmental impacts and the economic costs are set only to become worse, even in the short term. Continued increases in plastic production and consumption, combined with wasteful uses, inefficient waste collection infrastructures and insufficient waste management facilities, especially in developing countries, mean that even achieving already established objectives for reductions in marine litter remains a huge challenge, and one unlikely to be met without a fundamental rethink of the ways in which we consume plastics. This document was prepared by a working group of Regional Centres of the Stockholm and Basel Conventions and related colleagues intended to be a background document for discussion in the 2017 Conference of the Parties (COP) of the Basel Convention on hazardous wastes and the Stockholm Convention on persistent organic pollutants (POPs). The COP finally approved that the issue of plastic waste could be dealt by its Regional Centres and consistently report their activities on the matter to next COP’s meetings.
The effects of organic matter (80% humic and 15% fulvic acid) and coexistence of heavy metals (Ni, Pb and Zn) on sorption of three polycyclic aromatic hydrocarbons (PAHs)—acenaphthene, fluorene and fluoranthene—were examined for kaolinite, 60% kaolinite + 40% sand, and 43% kaolinite + 42% sand + 15% bentonite. In total 108 batch sorption tests of PAHs were conducted for three types of clay mineral mixtures in six possible combinations of soil organic matter and heavy metal contents from no heavy metals and organic matter added to maximum organic matter added with spiked heavy metals. Results showed that the existence of metals increased the sorption of PAHs onto kaolinite from 4.7% for acenaphthene to 17.9% for fluoranthene. Organic matter in a kaolinite-sand-bentonite matrix could increase PAH sorption by up to 140% for fluoranthene. In all cases, increases were greater for fluoranthene, a larger PAH molecule. Heavy metals coexisting with organic matter led to enhanced sorption of PAHs compared to clay minerals without organic matter. Synergistic effects of organic matter and heavy metals on PAH sorption increments in the mixtures studied were such that the overall sorption could be 10–41% higher than that based on summation of the separate effects of metals and organics.
La adsorción es un método ampliamente utilizado para el tratamiento de contaminantes disueltos. Diversos residuos agroindustriales han sido explorados como potenciales adsorbentes, mostrando alta eficiencia en la eliminación de colorantes. Para el escalado de este proceso se requieren modelos cinéticos y de equilibrio para cada pareja adsorbato-adsorbente. En este trabajo se evaluaron el equilibrio, la cinética y la termodinámica del sistema tuza de maíz-rojo 40 bajo sistema discontinuo a pH = 2.0 a las temperaturas de 25, 40 y 55 °C. Los modelos de Langmuir, Freundlich y Temkin fueron seleccionados para la representación de las isotermas, en tanto que las ecuaciones de Lagergren, Ho y Elovich, para la cinética del proceso. El modelo de Freundlich presentó el mejor ajuste a las isotermas, la cinética de adsorción fue mejor descrita por la ecuación de Ho y los valores para la energía libre de Gibbs, y la entropía señalaron la espontaneidad y factibilidad del proceso.
Over the last 60 years plastics production has increased manifold, owing to their inexpensive, multipurpose, durable and lightweight nature. These characteristics have raised their demand that will continue to grow over the coming years. However, with increased plastic materials production, comes increased plastic material wastage creating a number of challenges, as well as opportunities to the waste management industry. The present overview highlights the waste management and pollution challenges, emphasising on the various chemical substances (known as "additives") contained in all plastic products for enhancing polymer properties and prolonging their life. Despite how useful these additives are in determining the functionality of polymer products, their potential to contaminate soil, air, water and food is widely documented in the literature and described herein. These additives can potentially migrate and undesirably lead to human exposure via, e.g. food contact materials, such as packaging. They can, also, be released from plastics during the various recycling and recovery processes and from the products produced from recyclate. Thus, sound recycling has to be performed in such a way as to ensure that emission of substances of high concern and contamination of recycled products is avoided, ensuring environmental and human health protection, at all times.
In the present study, poly (ethylene terephthalate)-based composites were produced and characterized. These composites were composed by poly (ethylene terephthalate) (PET) reinforced with geopolymer concrete waste (GCW). Both untreated (U-GCW) and treated with oleic acid (OA) geopolymer concrete waste (T-GCW) were used in the production of the composites. The PET/GCW ratios used for either treated or untreated GCW bodies were 80/20 (wt%), 60/40 (wt%) and 50/50 (wt%). Chemical compositions were assessed by X-ray fluorescence spectroscopy (XRF), crystallinity by differential scanning calorimetry (DSC), thermal stability by thermogravimetry (TGA), microstructure by field emission gun scanning electron microscopy (FEG-SEM) with energy dispersive X-ray spectroscopy (EDS), and mechanical properties were assessed by compression tests. Fourier transform infrared spectroscopy (FT-IR) was used to check the efficiency of the treatment with OA, as well as the interaction between PET and GCW. The T-GCW PET composites showed better thermal, physical, and mechanical properties, for non-structural applications, when compared to U-GCW.
In this research, pine-sawdust pyrolytic char (PyC) was activated by phosphoric acid through microwave irradiation and activated PyC (APC) was obtained. The characterization of APC was presented, such as scanning electron microscope, pHpzc, Brunauer–Emmett–Teller surface area, surface functional group, etc. Surface area of APC was 683 m² g⁻¹ while average radius of pore was 1.5 nm. Then, APC was used as adsorbent to remove 4-chloro-2,5-dimethoxy nitrobenzene (CDNB) from aqueous solution in batch mode. Several experimental factors like initial pH, NaCl concentration, contact time, solution temperature were evaluated. Solution pH within 2–5 was in favor of adsorption and common salts had no effect on adsorption quantity. The adsorption capacity from experiment was up to 220.8 mg g–1 at 297 K. Langmuir model and Freundlich model were used to fit the adsorption equilibrium data and both can better predict the process. The kinetic process was better fitted by pseudo-second-order kinetic model and the process was controlled by film diffusion process. CDNB-loaded APC can be regenerated by 70% ethanol and adsorption capacity decreased after regeneration. It was concluded that APC be good adsorbent to remove CDNB from solution.
Plastics have outgrown most man-made materials and have long been under environmental scrutiny. However, robust global information, particularly about their end-of-life fate, is lacking. By identifying and synthesizing dispersed data on production, use, and end-of-life management of polymer resins, synthetic fibers, and additives, we present the first global analysis of all mass-produced plastics ever manufactured. We estimate that 8300 million metric tons (Mt) as of virgin plastics have been produced to date. As of 2015, approximately 6300 Mt of plastic waste had been generated, around 9% of which had been recycled, 12% was incinerated, and 79% was accumulated in landfills or the natural environment. If current production and waste management trends continue, roughly 12,000 Mt of plastic waste will be in landfills or in the natural environment by 2050.
The aim of this study was to determine the concentration of heavy metals in the sediments of Periyakalapet to Parangipettai coast, east coast of Tamil Nadu, by using energy-dispersive X-ray fluorescence (EDXRF) technique. The average heavy metal concentrations in the sediment samples were found in the order Al > Fe > Ca > Ti > K > Mg > Mn > Ba > V > Cr > Zn > La > Ni > Pb > Co > Cd > Cu. The average heavy metal concentrations were below the world crustal average. The degree of contamination by heavy metals was evaluated using pollution indices. The results of pollution indices revealed that titanium (Ti) and cadmium (Cd) were significantly enriched in sediments. Pearson correlation analysis was performed among heavy metal concentrations to know the existing relationship between them. Multivariate statistical technique was employed to identify the heavy metal pollution sources.
Microplastics are widespread contaminants in terrestrial environments but comparatively little is known about interactions between microplastics and common terrestrial contaminants such as zinc (Zn). In adsorption experiments fragmented HDPE bags c. 1 mm2 in size showed similar sorption characteristics to soil. However, when present in combination with soil, concentrations of adsorbed Zn on a per mass basis were over an order of magnitude lower on microplastics . Desorption of the Zn was minimal from both microplastics and soil in synthetic soil solution (0.01 M CaCl2), but in synthetic earthworm guts desorption was higher from microplastics (40 - 60%) than soil (2 - 15 %), suggesting microplastics could increase Zn bioavailability. Individual Lumbricus terrestris earthworms exposed for 28 days in mesocosms of 260 g moist soil containing 0.35 wt% of Zn-bearing microplastic (236-4505 mg kg-1) ingested the microplastics, but there was no evidence of Zn accumulation, mortality or weight change. Digestion of the earthworms showed that they did not retain microplastics in their gut. These findings indicate that microplastics could act as vectors to increase metal exposure in earthworms, but that the associated risk is unlikely to be significant for essential metals such as Zn that are well regulated by metabolic processes.
Microplastics (MPs) are prevalent in marine ecosystems. Because toxicants (termed here “co-contaminants”) can sorb to MPs, there is potential for MPs to alter co-contaminant bioavailability. Our objective was to demonstrate sorption of two co-contaminants with different physicochemistries [phenanthrene (Phe), log10Kow = 4.57; and 17α-ethinylestradiol (EE2), log10Kow = 3.67] to MPs; and assess whether co-contaminant bioavailability was increased after MP settlement. Bioavailability was indicated by gene expression in larval zebrafish. Both Phe and EE2 sorbed to MPs, which reduced bioavailability by a maximum of 33% and 48% respectively. Sorption occurred, but was not consistent with predictions based on co-contaminant physicochemistry (Phe having higher log10Kow was expected to have higher sorption). Contaminated MPs settled to the bottom of the exposures did not lead to increased bioavailability of Phe or EE2. Phe was 48% more bioavailable than predicted by a linear sorption model, organism-based measurements therefore contribute unique insight into MP co-contaminant bioavailability.
Microplastics have been increasingly detected and quantified in marine and freshwater environments, and there are growing concerns about potential effects in biota. A literature review was conducted to summarize the current state of knowledge of microplastics in Canadian aquatic environments; specifically, the sources, environmental fate, behaviour, abundance, and toxicological effects in aquatic organisms. While we found that research and publications on these topics have increased dramatically since 2010, relatively few studies have assessed the presence, fate, and effects of microplastics in Canadian water bodies. We suggest that efforts to determine aquatic receptors at greatest risk of detrimental effects due to microplastic exposure, and their associated contaminants, are particularly warranted. There is also a need to address the gaps identified, with a particular focus on the species and conditions found in Canadian aquatic systems. These gaps include characterization of the presence of microplastics in Canadian freshwater ecosystems, identifying key sources of microplastics to these systems, and evaluating the presence of microplastics in Arctic waters and biota.
Marine plastics have shown to contain various environmental chemicals. For evaluating the potential of plastics to influence regional and global dynamics of these chemicals and to serve as a vector to marine biota, understanding of sorption and desorption of chemicals by plastics is important. In this chapter, the equilibrium sorption of neutral organic chemicals from water to plastics is discussed. First, the basic principles of equilibrium sorption are explained, and then, factors that influence the magnitude of the sorption coefficient, such as types of plastics and chemicals, temperature, coexisting organic and inorganic constituents in water, are overviewed. Successively, effects on the equilibrium sorption properties of field-relevant mechanisms such as degradation and biofouling as well as nano-sized plastics are discussed. It is evident that studies on sorption properties of aged plastics in field conditions are far less available than those of intact plastics in laboratory conditions.
The prevalence of microplastics (<5 mm) in natural environments has become a widely recognised global problem. Microplastics have been shown to sorb chemical pollutants from their surrounding environment, thus raising concern as to their role in the movement of these pollutants through the food chain. This experiment investigated whether organic pollutants sorbed to microbeads (MBs) from personal care products were assimilated by fish following particle ingestion. Rainbow fish (Melanotaenia fluviatilis) were exposed to MBs with sorbed PBDEs (BDE-28, -47, -100, -99, -153, -154, -183 200 ng g-1; BDE-209 2000 ng g-1) and sampled at 0, 21, 42 and 63 days along with two control treatments (Food Only and Food + Clean MBs). Exposed fish had significantly higher ∑8PBDE concentrations than both control treatments after just 21 days, and continued exposure resulted in increased accumulation of the pollutants over the experiment (ca. 115 pg g-1 ww d-1). Lower brominated congeners showed highest assimilation whereas higher brominated congeners did not appear to transfer, indicating they may be too strongly sorbed to the plastic or unable to be assimilated by the fish due to large molecular size or other factors. Seemingly against this trend, however, BDE-99 did not appear to bioaccumulate in the fish, which may be due to partitioning from the MBs or that it was metabolised in vivo. This work provides evidence that MBs from personal care products are capable of transferring sorbed pollutants to fish that ingest them.
Due to the widespread use and durability of synthetic polymers, plastic debris occurs in the environment worldwide. In the present work, information on sources and fate of microplastic particles in the aquatic and terrestrial environment, and on their uptake and effects, mainly in aquatic organisms, is reviewed. Microplastics in the environment originate from a variety of sources. Quantitative information on the relevance of these sources is generally lacking, but first estimates indicate that abrasion and fragmentation of larger plastic items and materials containing synthetic polymers are likely to be most relevant. Microplastics are ingested and, mostly, excreted rapidly by numerous aquatic organisms. So far, there is no clear evidence of bioaccumulation or biomagnification. In laboratory studies, the ingestion of large amounts of microplastics mainly led to a lower food uptake and, consequently, reduced energy reserves and effects on other physiological functions. Based on the evaluated data, the lowest microplastic concentrations affecting marine organisms exposed via water are much higher than levels measured in marine water. In lugworms exposed via sediment, effects were observed at microplastic levels that were higher than those in subtidal sediments but in the same range as maximum levels in beach sediments. Hydrophobic contaminants are enriched on microplastics, but the available experimental results and modelling approaches indicate that the transfer of sorbed pollutants by microplastics is not likely to contribute significantly to bioaccumulation of these pollutants. Prior to being able to comprehensively assess possible environmental risks caused by microplastics a number of knowledge gaps need to be filled. However, in view of the persistence of microplastics in the environment, the high concentrations measured at some environmental sites and the prospective of strongly increasing concentrations, the release of plastics into the environment should be reduced in a broad and global effort regardless of a proof of an environmental risk.
Electronic supplementary material
The online version of this article (doi:10.1186/s12302-015-0069-y) contains supplementary material, which is available to authorised users.
Methods for treating industrial wastewater containing heavy metals often involve technologies for reduction of toxicity in order to meet technology-based treatment standards. This article was focused on the recently developed and newly applicable various treatment processes for the removal of heavy metals from industrial wastewater. Physico-chemical removal processes such as; adsorption on new adsorbents, ion exchange, membrane filtration, electrodialysis, reverse osmosis, ultrafiltration and photocatalysis were discussed. Their advantages and drawbacks in application were evaluated. In the processes of biological treatments microorganisms play a role of settling solids in the solution. Activated sludge, trickling filters, stabilization ponds are widely used for treating industrial wastewater. Bioadsorption is a new biological method and various low cost bioadsorbents (agricultural waste, forest waste, industrial waste, algae etc.) are used for maximum removal of heavy metals from wastewater. Bioadsorption techniques are eco friendly best solutions for removing heavy metals from wastewater rather than physic-chemical methods. But chemical methods are most suitable treatments for toxic inorganic compounds produced from various industries which cannot removed from any biological and physical techniques.
Environmental contextMany trace metals including lead are only sparingly soluble in seawater and may exist in both dissolved and particulate forms (e.g. as precipitates). Aquatic organisms may experience different toxic effects from exposure to dissolved and particulate trace metals. This study reports the limits to lead solubility in seawater that influence the exposure to these forms of lead in the field and the laboratory. AbstractA combination of laboratory investigations and thermodynamic modelling were conducted in order to gain an understanding of the factors controlling lead solubility in seawater. In experiments where increasing amounts of lead were added to seawater (in order to avoid supersaturation) and equilibrated for up to 28 days, the maximum solubility was similar to 2mgL(-1) (pH 8.15, 22 degrees C). However, at higher added lead concentrations, which caused the rapid formation of lead precipitates, the solution chemistry became dynamic and the observed solubility was markedly lower, varying with both reaction time and precipitate concentration. For instance, when seawater solutions were spiked with 10mgL(-1) of total lead, precipitation occurred immediately and only 1.6mgL(-1) of dissolved lead was measured after 1h, with this concentration decreasing to 1.3mgL(-1) after 28 days. The solubility of lead in artificial seawater (0.68mgL(-1)) was much lower than in natural seawater. This difference was attributed to the significant role played by natural organic matter in complexing dissolved lead. X-Ray diffraction and elemental analysis data suggest that the phase controlling lead solubility is a previously unidentified lead chlorocarbonate, which rapidly transforms to hydrocerussite on washing with deionised water. These observations are of particular relevance to toxicity tests where organisms are exposed to wide ranges of metal concentrations in order to obtain dose-response curves.
The concentrations of trace metals (V, Al, Sn, As, and Se) were measured in seawater, sediments, and muscles of fish species collected from beaches of Marsa Matrouh, North West coast of Egypt. The decreasing trend of metals was observed in water as Al > Sn > As > V > Se and in sediment as Al > Sn > V > As > Se. The levels of dissolved V, Se and As were lower than the typical natural trace element concentration of seawater while, Al surpassed. Dissolved Sn concentration was higher than the background concentration (0.01 μg/l) but it is still lower than the toxic concentration for organisms. Pollution load index (PLI) recorded values >1 indicate progressive deterioration of the sediment quality. Enrichment factor (EF), contamination factor (CF) and geoaccumulation index (Igeo) demonstrated that most of the sediment samples were moderately to heavily contaminated by Sn which surpassed the threshold limit value (TLV). Metal bioaccumulation in the muscles of fish species was in the decreasing order of Al > Sn > V > Se, while As was not detected in all species. Calculated metal pollution indices (MPI) were lower than 1 except in Saurida undosquamis with 1.43 indicating that it is safe for human consumption.
The Jinzhou Bay is one of the bays polluted heavily by the heavy metals. Twenty surface seawater samples were collected to analyze the dissolved and particulate concentrations of Cu, Pb, Zn, Cd, Hg and As using the methods of Atomic Absorption and Atomic Fluorescence. The heavy metal distribution characteristics, influencing mechanism and the distribution ratio between particulate and dissolved state were analyzed. The results showed that the concentration of Cd in 25% stations was higher than the first standard value of sea water quality. The concentration of As was lower than the standard value in all stations. The concentration of dissolved heavy metal was highest in west closer to the land and Wuli River estuary, and decreased from west to east. There was lower value area of heavy metals like tongue caused by the tidal. The particulate Pb concentration accounted for 83.00% in total concentration, and the other heavy metals in particulate state were lower than that in the dissolved state. The pollution of the particulate heavy metals was becoming more and more serious from open sea to offshore marine areas. Therefore the heavy metals distribution in the Bay was affected not only by the coastal pollutants but also by the hydrodynamic factors. (C) 2011 Published by Elsevier B. V. Selection and/ or peer-review under responsibility of School of Environment, Beijing Normal University.
Microplastics (MPs) as new pollutants of environmental concern have been widely detected in sewage sludge, and may act as significant vectors for metal pollutants due to their adsorption property. Our findings show that Cd, Pb, and Co, but not Ni, contents in sewage sludge are lower than that of corresponding metal irons adsorbed on sludge-based MPs, indicating that the MPs accumulate such metal pollutants as Cd in the sludge samples. In contrast to virgin MPs, sludge-based MPs are one order of magnitude higher adsorption capacity for Cd, which reaches up to 2.523 mg g À1 , implying that there is a considerable enhancement in adsorption potential of the MPs for metals after the wastewater treatment process. SEM analysis shows that sludge-based MPs have rougher and more porous surface than virgin MPs, and FTIR spectra reveal that functional groups such as CeO and OeH are found on sludge-based MPs. Further, two-dimensional FTIR correlation spectroscopy indicates that CeO and NeH functional groups play a vital role in the process that sludge-based MPs adsorb Cd, which are not found in virgin MPs. The results imply that increased adsorption potentials of the sludge-based MPs to Cd are attributed to changes in the MP physicochemical properties during wastewater treatment process. In addition, such factors as pH value, and sludge inorganic and organic components also have an effect on the MP adsorption to Cd. Principal component analysis shows that the MPs could be divided into three categories , i.e. polyamide, rubbery MPs (polyethylene and polypropylene) and glassy MPs (polyvinyl chloride and polystyrene). Their adsorption potentials to Cd follow the decreasing order: polyamide > rubbery MPs > glassy MPs. In summary, these findings indicate that MPs may exert an important influence on fate and transport of metal pollutants during sewage sludge treatment process, which deserves to be further concerned.
In aquatic environments, plastic debris accumulates chemical pollutants from the surrounding water, potentially altering the fate of xenobiotics in these ecosystems. The effects of biofouling on the potential for plastic to sorb environmental pollutants remain poorly understood. In this study, we test the hypothesis that concentrations of metals are directly related to biofilm accumulation on microplastics submerged in natural estuarine waters. Two types of pre-production plastic pellets (polylactic acid (PLA) and low-density polyethylene (LDPE)) and glass pellets, were suspended for up to 28 days in an urbanized estuary (San Francisco Bay, California) to investigate how biofilm affects the accumulation of metals on these materials. During the initial weeks of the experiment, biofilm growth differed between locations, but after 28 days, PLA and LDPE had similar amounts of biofilm at the two field sites. Biofilm was the only significant predictor variable for Ba, Cs, Fe, Ga, Ni and Rb, and simple regressions of these metals after one month of submersion predicted much of the variability in the data (respective adjusted R² values: 0.46, 0.90, 0.86, 0.81, 0.87, 0.90; p < 0.001). For other metals influenced by location or substrate material, multivariate analysis showed that increases in metal concentrations were predicted by increases in biofilm for Cu, Pb, Al, K, U, Co, Mg (p < 0.001) and Mn (p < 0.01). This work highlights the role of biofilm in facilitating metal accumulation on plastic debris and contributes to current understanding of the underlying processes that influence the behavior of microplastics as aquatic contaminants.
Microplastics (MPs) as new pollutants of environmental concern have been widely detected in sewage sludge, and may act as significant vectors for metal pollutants due to their adsorption property. Our findings show that Cd, Pb, and Co, but not Ni, contents in sewage sludge are lower than that of corresponding metal irons adsorbed on sludge-based MPs, indicating that the MPs accumulate such metal pollutants as Cd in the sludge samples. In contrast to virgin MPs, sludge-based MPs are one order of magnitude higher adsorption capacity for Cd, which reaches up to 2.523 mg g−1, implying that there is a considerable enhancement in adsorption potential of the MPs for metals after the wastewater treatment process. SEM analysis shows that sludge-based MPs have rougher and more porous surface than virgin MPs, and FTIR spectra reveal that functional groups such as CO and OH are found on sludge-based MPs. Further, two-dimensional FTIR correlation spectroscopy indicates that CO and NH functional groups play a vital role in the process that sludge-based MPs adsorb Cd, which are not found in virgin MPs. The results imply that increased adsorption potentials of the sludge-based MPs to Cd are attributed to changes in the MP physicochemical properties during wastewater treatment process. In addition, such factors as pH value, and sludge inorganic and organic components also have an effect on the MP adsorption to Cd. Principal component analysis shows that the MPs could be divided into three categories, i.e. polyamide, rubbery MPs (polyethylene and polypropylene) and glassy MPs (polyvinyl chloride and polystyrene). Their adsorption potentials to Cd follow the decreasing order: polyamide > rubbery MPs > glassy MPs. In summary, these findings indicate that MPs may exert an important influence on fate and transport of metal pollutants during sewage sludge treatment process, which deserves to be further concerned.
Plastic pollution in oceans is a global problem, with growing research efforts focusing on the threat of microplastics (<5 mm fractions). A source of microplastics pollution is derived from personal care products that contain polyethylene micro-spheres which are not captured by wastewater plants. In this work, ten personal care products (mainly scrubs) containing microplastics and marketed in Spain, were physico-chemically characterized. The obtained results proved that those microplastics had different particle size and are presented in high percentages in some cases, between 6 and 7% of the total product. Products with smaller particles usually showed higher concentrations than products with larger particles. Although all the microplastics were shown to be polyethylene, some impurities were observed that demonstrated the presence of silicates and oxides in the microplastics. Regards to morphology, the shape of the particles was irregular in general, although some completely spherical particles can be observed.
Plastics are a frequently observed component of marine debris and there is growing concern about microplastic (MP) ecotoxicity, and the impacts of additives, sorbed hazardous organic contaminants, heavy metals, and biofilm on MP surfaces. The relative importance of MP from different terrestrial and freshwater sources is poorly understood and limits our ability to develop best management practices. This review focuses on evidence and methods for source apportionment of MP in freshwater environments including the use of MP characteristics, mass balance techniques, and surface characteristics. Within-study data indicated some potential for differences in polymer identity and morphology for differentiating select sources, but clear cross-study patterns were lacking. Major challenges identified include technical challenges in accurately identifying polymers, multiple classification schemes for reported MP morphologies, lack of data for several terrestrial sources, poor understanding of differential fate/transport/weathering processes for MP and surface contaminants, and methodological difficulties simultaneously confirming polymers and surface contaminants.
In recent years, microplastics in oceans have become a serious environmental problem and the focus of attention. In the present study, the sorption of TBC and HBCDs by microplastics in simulated seawater is examined. The effects of particle size, temperature, salinity, and concentration on the adsorption of TBC and HBCDs by microplastics are studied. Results indicate that the first-order adsorption kinetic model is more suitable than the pseudo-second-order kinetic model to describe adsorption. The equilibrium adsorption times are 15 h and 10 h for TBC and HBCDs, respectively. The adsorption capacity increases with the decrease in particle size. The adsorption capacity gradually increases at first and then decreases with the increase in salinity and temperature. The maximum adsorption capacity is at 15 °C and 14% salinity. Compared with the linear and Freundlich models, the Langmuir model is more suitable; this indicates that the main adsorption mechanism might be chemical adsorption.
