An ignored potential microplastic contamination of a typical waste glass recycling base

Pollution characteristics and release mechanism of microplastics in a typical end-of-life vehicle (ELV) recycling base, East China

Microplastics (MPs) is a novel and significant pollution due to its eco-environmental hazards and ubiquity. In end-of-life vehicle (ELV) recycling base, MPs are widely distributed but have rare reported in scientific literature. In this study, a comprehensive analysis of MPs was conducted in a typical ELV recycling base. MPs were found in all samples at different sampling sites and environmental mediums. A total of 34 polymer types were detected by μ-FTIR, and the main polymers include PE-PP, ABS, polyester resin, nylon, and PEU plastic. MPs were released from the crushing, tearing, and breaking of plastic parts in ELVs. They were in high content in ground dust, with the abundance of 737-29,021 p/5 g D (the average abundance of 5552 ± 6435 p/5 g D). The abundance, shape, color, and size of MPs are related with functional areas of ELV recycling. Heavy metals could be adsorbed on MPs, and their contents on MPs have a significant correlation with those in the corresponding dust samples. At last, some specific MPs control measures, such as changing transportation mode, using dust-proof cloths, and equipping dust removal equipment, have been put forward.

Spatial distribution, source apportionment and potential ecological risk assessment of suspended atmosphere microplastics in different underlying surfaces in Harbin

Although suspended atmospheric microplastics (SAMPs) have been found to be ubiquitous and have potential impacts on human health, whereas studies related to source apportionment and potential ecological risk assessment in the atmospheric environment are still limited. This study investigated spatial distribution, source apportionment and potential ecological risk of SAMPs in six underlying surfaces of Harbin, China. The results show that all six underlying surfaces existed SAMPs, including polypropylene (PP), polyethylene terephthalate (PET) polyethylene (PE), polystyrene (PS) and polyvinyl chloride (PVC), with approximate 26.13 %, 24.10 %, 23.87 %, 13.51 %, and 12.39 %, respectively. SAMPs abundances from filtered air were relatively high and averaged 1.76 n/m3. The SAMPs mainly contained fibrous (59.01 %), fragmented (30.18 %), and granular (10.81 %) with transparent (62.39 %), black 13.74 %), red (7.43 %), white (6.53 %), blue, and yellow (3.60 %), and particle size ranged from 1.3 to 518 μm. In addition, source apportionment of SAMPs shows that SAMPs were originated from five emission sources including living source (19.53 %), construction source (12.08 %), transportation source (47.25 %), industrial source (5.11 %), and agricultural source (16.13 %) in Harbin. A significant correction was observed between SAMPs abundances and human activity (R = 0.68, P = 0.66), atmospheric humidity (R = -0.40, P = 0.02), and wind direction (R = 0.22, P = 0.04) in different underlying surface. Furthermore, potential ecological hazardous single index (EI) of PVC and PS were higher than PP, PET, and PS in the construction land, cultivated land, forest land, grassland, water area, and unused land. An estimation of the potential ecological risk index (RI) from SAMPs using Positive Matrix Factorization (PMF) model indicated that Harbin presented a minor ecological risk with average 16.59 of RI index of microplastics in environments. In conclusion, data in this study indicate that SAMPs are existed in atmospheric environments, which have possible risks for human health via inhalation.

Research on compound pollution characteristics and health risk evaluation of particulate matter and heavy metals in waste glass recycling process

Owing to the large amount of waste glass generated, the waste glass recycling base is an indispensable municipal supporting facility of a sustainable city. However, waste glass recycling is a complex process involving stages such as multiple-stage crushing and material sorting. Consequently, waste glass recycling base has a considerable impact on the surrounding environment, such as health risk of particulate matter on workers. In this study, we aimed to perform a comprehensive investigation and analysis of compound pollution characteristics and health risk evaluation of particulate matter and heavy metals generated from waste glass recycling process. Soil, particulate fallout, and glass samples were collected from inside and outside a recycling plant in eastern China. Our findings showed that the waste glass treatment process produces a large amount of air particulate matter, and the PM2.5 and PM10 concentrations can reach 3725 and 4055 μg/m3, respectively, in the production workshop during working hours. Meanwhile, the monitoring results show that the concentration of heavy metals on fine particles is higher compared to coarse particles. The high Zn and Pb concentrations detected in the soil and dustfall were proved to be derived from the glass raw materials. However, health risk assessment and particle deposition modeling in the human respiratory system revealed that heavy metals from the air particulate matter have no significant carcinogenicity or non-carcinogenic risk. The Gaussian dispersion model showed that the impact of particulate matter on the surrounding environment and health of the surrounding residents is minimal. Furthermore, transportation is the major emission link according to the particulate emission calculation, indicating that it is imperative to upgrade and reform the existing processes of waste glass recycling. Taken together, this study provides a scientific basis for the green development of waste glass recycling process and further environmental information regarding waste glass recycling plants.

Spatiotemporal distribution and potential sources of atmospheric microplastic deposition in a semiarid urban environment of Northwest China

In this study, the spatiotemporal distribution of microplastic deposition was investigated through ordinary Kriging interpolation, and the potential sources of microplastic deposition were identified by using Hybrid Single-Particle Lagrangian Integrated Trajectory model. The results showed that the total deposition flux of microplastics ranged from 79.5 to 810.0 p/(m²·d). The shapes of microplastics could be divided into 4 shapes: fiber, fragment, film, and pellet. Seven polymer types of microplastics were identified, including polyamide (PA), polyethylene (PE), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC). Most microplastics were tiny and small sizes (≤ 500 μm) and colorless. Through model analysis and survey, microplastic deposition came from the study region, and the potential sources might be plastic products and wastes. The seasons with the highest and lowest total deposition flux were summer (535.5 p/(m²·d)) and winter (197.5 p/(m²·d)), respectively. The months of the highest and lowest total deposition flux were June 2021 (681.4 p/(m²·d)) and January 2022 (112.2 p/(m²·d)), respectively. Most fibers (PET, PA, PP) and fragments (PP) were distributed in populous areas such as commercial centers and residential areas. Abundant fragments (PET, PS, PE) and films (PE, PVC) were distributed around salvage stations. Almost all of the pellets (PE, PMMA) were found in the factory. Our results suggested that the temporal distribution of microplastic deposition was influenced by precipitation and mean temperature of air, and the spatial distribution of microplastic deposition was influenced by sources and population density.

Characteristics of microplastics and the role for complex pollution in e-waste recycling base of Shanghai, China

Plastics used in electric and electronic products cover a wide range, and contain many additives, such as brominated flame retardant and so on. These compounds and microplastics may be released into environment when the electric and electronic products are obsoleted and recycled. This study explores the characteristics of microplastics and the complex pollutions in a formal e-waste recycling base in Shanghai, China. The maximum abundance of microplastics is observed in dust samples of the recycling base and the average abundance is 44277 ± 69032p/50 g. 103 kinds of polymers are identified, including 4 kinds of packaging plastics, 32 kinds of engineering plastics, 18 kinds of rubber, and 49 kinds of other polymers. It is found that microplastics show weak adsorption effect for heavy metals. However, microplastics are important carrier of ∑₈PBDEs released during the whole recycling processes, and BDE-209 account for more than 50 % of PBDEs in microplastics. It is estimated that the microplastics load inside the e-waste recycling base was 4.01 tons based on the measured statistics. This study will provide theoretical basis for further understanding the potential pollution of microplastics and upgrading the corresponding control measures.

Ignored microplastic sources from plastic bottle recycling

The recovery and recycling of plastic products has increased dramatically in recent years as a strategy to achieve sustainable production and minimization of plastic pollution. However, the release of microplastics during plastic recycling has received little attention. We evaluated the generation and fate of microplastics in three typical facilities which make polyethylene terephthalate (PET) flakes using post-consumer PET bottles as raw material. Microplastics, 0.1- 5.0 mm in size, were detected in production wastewater at concentrations ranging from 23.43 ± 1.04 mg/L to 1836.37 ± 31.73 mg/L, while decreased to (8.13 ± 0.42-83.83 ± 0.93) mg/L in discharge effluent and (52,166 ± 2858-68,866 ± 2500) μg/g in sludge. Interestingly, the profiles of microplastics in samples from production wastewater, effluents, and sludge showed significant differences. Although, in all three compartments, the mass of microplastics increased, and the particle number decreased with increasing particle size. Overall, the removal ratio of total microplastics from the production wastewater was 53.47 ± 4.48% to 99.56 ± 0.02% in mass, and from 90.08 ± 0.82% to 99.56 ± 0.05% in quantity. The loss of microplastics from wastewater resulted in their concentration in sludge. Factors that influence the transfer of microplastics from wastewater to sludge should be identified and utilized to maintain a high level of removal and prevent leakage of these particles into the environment.

Characteristics of unorganized emissions of microplastics from road fugitive dust in urban mining bases

Nowadays, plastic pollution attracts attention, while data on microplastic (MP) emissions to atmosphere from urban mining bases are rarely quantified. In this paper, the emission characteristics of MPs in road fugitive dust from two urban mining bases were studied, the emission factors of MPs from road fugitive dust source were updated, and emission inventories were established. It is estimated that the waste glass recycling base and the e-waste dismantling plant emit 1265.53 g and 40.5 g of MPs into atmosphere respectively each year, with the highest percentage of tire micro-rubber. The roads with the most emissions are located in the middle of warehouses and workshops. Emission factors for MPs mainly depend on average vehicle weight, and heavy vehicles cause more MP emissions. Uncertainty analysis of the inventory indicated that the random error of MP emissions on a single road in waste glass recycling base was -79.1%-187.1%, while in e-waste dismantling plant was -62.7%-102.05%, which is mainly related to the silt loading. This study completes the quantitative data on the unorganized emissions of MPs from road fugitive dust in these two typical urban mining bases, and provides guidance for air pollution prevention and control.