A system for simulating the effects of weathering on the adsorption of heavy metals by microplastics

Abstract

System for simulating the effect of weathering on the adsorption of heavy metals by microplastics, comprising: a) a sample preparation module configured to select, clean and divide plastic samples into weathered and unweathered categories; b) a weathering simulation module comprising an orbital shaker with a sand-water mixture and an abrasive treatment to imitate natural weathering processes; c) a heavy metal exposure module for the production and maintenance of a controlled solution containing nickel (Ni), lead (Pb), zinc (Zn), cadmium (Cd), cobalt (Co) and copper (Cu) in predefined concentrations for the purpose of exposing plastic samples over a prolonged period of time; d) a digestion and extraction module with nitric acid treatment and centrifugation for the extraction of adsorbed heavy metals from the plastics; e) an analytical evaluation module that uses atomic absorption spectroscopy (AAS) to quantify the degree of heavy metal adsorption on weathered and unweathered plastic surfaces; and f) a comparative analysis module to assess the differences in adsorption between weathered and non-weathered plastics, to determine the adsorption efficiency of different polymers and to assess the environmental impact of metal retention by microplastics.

Description

[0001] The present invention relates to a system for simulating the effects of weathering on the adsorption of heavy metals by microplastics. In particular, it includes controlled environmental conditions to evaluate adsorption fluctuations over time. The invention is applicable to environmental monitoring, pollution assessment, and remediation studies.

[0002] Microplastic pollution has become a significant environmental problem due to their persistence in aquatic and terrestrial ecosystems. These particles not only pose a direct ecological risk but also serve as carriers for various pollutants, including heavy metals. Over time, environmental weathering processes, such as UV irradiation, temperature fluctuations, and chemical interactions, alter the physicochemical properties of microplastics, affecting their adsorption capacity for toxic metals. However, current studies lack a standardized approach to systematically assess the impact of weathering on metal adsorption, resulting in conflicting and incomplete data regarding the long-term environmental risks of microplastics.

[0003] Existing methods for assessing the adsorption of heavy metals by microplastics often rely on static laboratory conditions that cannot replicate real environmental factors. Without an integrated simulation system, researchers struggle to predict adsorption behavior under dynamic conditions, limiting the accuracy of risk assessment. Furthermore, the impact of long-term weathering remains poorly understood, complicating the establishment of pollution control guidelines and remediation strategies. The lack of a controlled, reproducible system for simulating weathering effects represents a critical gap in environmental research.

[0004] To address this problem, the present invention provides a system that simulates weathering conditions to evaluate the adsorption of heavy metals by microplastics under controlled yet realistic conditions. By incorporating variables such as UV radiation, temperature cycling, and chemical exposure, the system allows researchers to quantify changes in adsorption behavior over time. This approach not only improves the understanding of the dynamics of microplastic pollution but also supports the development of effective strategies to mitigate heavy metal pollution in the environment.

[0005] The utility model relates to a technical field of wastewater treatment, specifically to a heavy metal wastewater treatment system. Heavy metal wastewater treatment equipment of this type includes a former feed liquid conveying system, a heavy metal adsorption system, a heavy metal analysis system, a filtration liquid conveying system, and a concentrate recycling system. The wastewater from the former feed liquid conveying system containing heavy metals is sent to the heavy metal adsorption system. The heavy metal adsorption system includes at least a heavy metal analysis system, a gas receiver, and a high-pressure forced lubrication gas device. This gas receiver is connected to the outlet pipe at the play water end by a high-pressure air supply system and an external bucket connection. The filtration liquid conveying system and the concentrate recycling system are connected to each other by a high-pressure air supply system and an external bucket connection.Above heavy metal sewage treatment plant can realize nanometer adsorbent and heavy metal ion's repeatedly used, and sewage treatment is effective, adsorption capacity is large, the analysis is efficient, can not cause secondary pollution, has extensive practicability beyond.

[0006] One objective of this disclosure is to simulate real-world weathering effects on microplastics to assess their environmental impacts.

[0007] Another objective of the present disclosure is the precise quantification of heavy metal adsorption using advanced analytical methods.

[0008] Another objective of the present disclosure is to improve the understanding of how degraded plastics contribute to environmental pollution.

[0009] Another objective of the present disclosure is to provide a comparative analysis of weathered and unweathered plastics to highlight adsorption differences.

[0010] A further objective of this disclosure is to enable the development of predictive models for heavy metal retention in plastics.

[0011] Another objective of the present disclosure is to support the development of sustainable materials by identifying polymers with lower environmental risk.

[0012] Another objective of the present disclosure is to contribute to improved waste management strategies by assessing the degradation and toxicity of plastics.

[0013] Another objective of the present disclosure is to assist in the development of more efficient strategies to control microplastic pollution in ecosystems.

[0014] The present invention generally relates to simulating the effects of weathering of microplastics, evaluating their ability to adsorb heavy metals such as Ni, Pb, Zn, Cd, Co and Cu.

[0015] In one embodiment of the present invention, processes such as mechanical abrasion, UV irradiation, and chemical interactions are incorporated to simulate the degradation of plastics in the real world.

[0016] A further embodiment of the invention consists in exposing plastic samples to a heavy metal solution over a longer period of time in order to investigate the adsorption dynamics in weathered and unweathered conditions.

[0017] In a further embodiment of the invention, atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectrometry are used for precise quantification of metal adsorption.

[0018] Another embodiment of the invention is that the system compares the adsorption capacities of weathered and unweathered plastics to evaluate the effects of surface degradation on metal retention.

[0019] Another embodiment of the invention is that the invention helps to understand how weathered plastics in natural environments can act as carriers for heavy metals, which poses a threat to ecosystems.

[0020] Another embodiment of the invention is that the system uses machine learning algorithms to analyze data and predict adsorption patterns based on environmental and material variables.

[0021] Another embodiment of the invention is that the system is useful for environmental monitoring, pollution control, and the development of sustainable material and waste management strategies.

[0022] The present invention relates to a system for simulating the influence of weathering on the adsorption of heavy metals by microplastics in order to assess how environmental degradation affects the ability of plastics to bind toxic metals. The system comprises a multi-stage experimental setup that replicates natural weathering processes such as mechanical abrasion, UV irradiation, and chemical interactions, followed by controlled exposure to solutions containing heavy metals such as nickel (Ni), lead (Pb), zinc (Zn), cadmium (Cd), cobalt (Co), and copper (Cu). Through a structured digestion and analysis process, the system quantifies the adsorption capacity of various polymers in both the weathered and unweathered state, thus providing important insights into pollution dynamics and the environmental risks associated with microplastics.

[0023] This invention is particularly valuable for environmental monitoring, pollution management, and materials science research, as it enables the systematic evaluation of microplastic behavior under real-world conditions. By integrating advanced analytical techniques such as atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectrometry (ICP-MS), the system ensures precise quantification of heavy metal retention.

[0024] The system consists of several modules designed to evaluate the adsorption of heavy metals by microplastics under both weathered and unweathered conditions. It begins with the selection and preparation of commonly used polymer samples. Fifteen different polymers commonly encountered in everyday life are collected, thoroughly cleaned, and washed with Milli-Q water to remove surface contaminants. These samples are then divided into two groups: one is subjected to simulated weathering, while the other remains unchanged as a control group.

[0025] To simulate natural weathering effects, the system includes a weathering simulation module that mimics mechanical and environmental degradation. The weathered plastic samples are vigorously shaken in an orbital shaker containing a sand-water mixture to simulate erosion and physical degradation similar to natural conditions. Additionally, a surface abrasion mechanism provides controlled scratching with sandpaper to enhance the degradation process and ensure a realistic weathering effect. Meanwhile, the unweathered plastic samples remain untreated and only undergo the initial cleaning process.

[0026] Once the plastics are conditioned, they are introduced into the heavy metal exposure unit. A prepared solution containing Ni, Zn, Cd, Pb, Cu, and Co at a specific concentration is placed in two separate beakers. The weathered and unweathered plastic samples are immersed in this solution for 40 days under controlled environmental conditions, allowing sufficient time for adsorption. The system ensures uniform exposure, maintaining stability in the test solution throughout the test period.

[0027] After the adsorption phase, the plastics are transferred to the metal extraction and analysis module. The samples are subjected to a nitric acid digestion process to extract the adsorbed heavy metals. After digestion, the extracted heavy metals are separated from the polymer samples in a centrifugation system operating at 150-200 rpm for 2 hours. The final analysis of the heavy metal concentration is performed using atomic absorption spectroscopy (AAS), which allows for precise quantification of the adsorption values.

[0028] The system works synergistically by integrating several experimental modules that together simulate the natural weathering processes of microplastics and evaluate their impact on heavy metal adsorption. First, the plastic samples are subjected to mechanical abrasion, UV irradiation, and chemical interactions to mimic real-world weathering. These weathered plastics are then exposed to a controlled solution of heavy metals, where adsorption is measured over time. Using advanced analytical techniques such as atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectrometry (ICP-MS), the system precisely quantifies the amount of heavy metals adsorbed by the plastics. A comparative analysis of weathered and unweathered plastics demonstrates the increased adsorption capacity due to weathering-induced surface roughness and microcracks.Machine learning algorithms process this data to create predictive models that improve understanding of how different materials and environmental conditions affect metal retention. This integrated approach enables a more accurate assessment of the environmental risks posed by microplastics and drives advances in pollution control, materials science, and sustainable waste management. Adsorption of nickel (Ni)

[0029] The system results show that weathered polymers in Set A exhibit significantly higher nickel adsorption than unweathered polymers in Set B. Among the weathered samples, nylon exhibits the highest nickel adsorption at 1.532 mg / g, followed by vinyl (0.995 mg / g) and polypropylene (0.835 mg / g). In contrast, unweathered samples show lower adsorption values, with polysiloxane (0.959 mg / g) and LDPE (0.654 mg / g) exhibiting the highest values. The system highlights that surface weathering increases the available surface area and creates more bonding sites, leading to increased nickel adsorption in weathered plastics. Adsorption of lead (Pb)

[0030] The system shows a significant difference in lead adsorption between weathered and unweathered plastics. In Set A, PVC has the highest lead uptake at 1.838 mg / g, followed by nylon (1.166 mg / g). In Set B, lead uptake is lower for all materials, although nylon (0.727 mg / g) and PVC (0.830 mg / g) still have the highest values. The considerable difference between the sets, especially for PVC and nylon, suggests that physical degradation, such as surface erosion and scratching, greatly increases the ability of plastics to bind lead, as simulated by the system. Adsorption of zinc (Zn)

[0031] The zinc adsorption results show that weathered plastics provide a more favorable environment for metal binding. In Set A, polysiloxane (0.929 mg / g), vinyl (0.714 mg / g), and polypropylene (0.625 mg / g) exhibit the highest adsorption values. In Set B, zinc adsorption decreases, but polysiloxane (0.609 mg / g) and vinyl (0.676 mg / g) still exhibit moderate adsorption values. The system confirms that increased surface roughness and microcracks caused by weathering contribute to enhanced zinc adsorption on plastic surfaces. Adsorption of cadmium (Cd)

[0032] The system results show that weathered plastics are more efficient at adsorbing cadmium. Nylon (0.906 mg / g) and vinyl (0.587 mg / g) in Set A exhibit the highest adsorption values. In contrast, the materials in Set B exhibit lower adsorption, with nylon (0.573 mg / g) having the highest capacity, followed by vinyl (0.251 mg / g) and LDPE (0.203 mg / g). The results indicate that surface degradation due to weathering significantly increases cadmium adsorption by increasing surface roughness and binding sites. Adsorption of cobalt (Co)

[0033] The system data show that the weathered plastics in Set A exhibit better cobalt adsorption. Nylon (0.736 mg / g) has the highest adsorption, followed by vinyl (0.480 mg / g) and polypropylene (0.452 mg / g). In Set B, nylon (0.529 mg / g) remains the leading polymer in cobalt adsorption, albeit with a significant reduction compared to the weathered conditions. These results underscore that weathering-induced surface defects create additional adhesion points that increase cobalt adsorption in weathered plastics. Adsorption of copper (Cu)

[0034] For copper, the system results show that the materials in Set A exhibit higher adsorption capacity than those in Set B. Nylon (0.762 mg / g) and vinyl (0.493 mg / g) exhibit the highest copper adsorption in weathered plastics. In Set B, nylon (0.452 mg / g) still leads, albeit with lower adsorption values. Similar to other metals, the system confirms that increased surface roughness and additional adsorption sites created by weathering enhance copper binding in weathered plastics. Example 2: System-based comparison between weathered and unweathered plastics

[0035] The system results show a significant difference in the adsorption capacity of weathered (Set A) and unweathered (Set B) plastics for trace metals. Weathered plastics exposed to physical abrasion and simulated environmental degradation exhibit higher surface roughness and more adsorption sites, which enhances their ability to bind metal ions. In contrast, unweathered plastics have smoother surfaces with fewer active binding sites, resulting in lower adsorption capacity.

[0036] The system consistently shows this trend for all tested metals (Ni, Pb, Zn, Cd, Co, Cu) and plastic compositions. Among these materials, nylon exhibits the highest adsorption values ​​in both the weathered and unweathered state, with a significant increase in adsorption capacity after weathering. Furthermore, PVC in Set A exhibits high lead deposition, while vinyl effectively binds several metals, especially in its weathered state.

[0037] By simulating natural weathering effects, the system demonstrates the potential of microplastics to act as contaminant carriers in environmental systems. Weathered plastics exhibit a greater capacity to adsorb and transport trace metals, increasing the risk of bioaccumulation and ecological impacts. This suggests that microplastic pollution, particularly in marine and terrestrial ecosystems, could contribute to the dispersal of heavy metals through food chains, further increasing concerns about environmental pollution.

[0038] The system results highlight the differences in heavy metal adsorption between weathered (Set A) and unweathered (Set B) polymers. Overall, weathered plastics exhibit significantly higher adsorption capacity due to their greater surface roughness and additional binding sites. Among all tested metals, nylon in Set A consistently shows the highest adsorption for most heavy metals, with 1.532 mg / g for nickel (Ni), 1.166 mg / g for lead (Pb), 0.906 mg / g for cadmium (Cd), 0.736 mg / g for cobalt (Co), and 0.762 mg / g for copper (Cu). The adsorption values ​​for nylon in Set B are significantly lower, highlighting the influence of surface weathering in improving metal retention.

[0039] For nickel (Ni), nylon (1.532 mg / g), vinyl (0.995 mg / g), and polypropylene (0.835 mg / g) exhibit the highest adsorption in Set A. However, in Set B, polysiloxane (0.959 mg / g) and LDPE (0.654 mg / g) exhibit the highest adsorption, although their values ​​are lower than those of their weathered counterparts. This confirms that mechanical weathering significantly increases the adsorption potential for nickel.

[0040] Lead (Pb) adsorption follows a similar trend, with PVC (1.838 mg / g) and nylon (1.166 mg / g) in Set A exhibiting the highest adsorption values. In contrast, the polymers in Set B exhibit a narrower range, with PVC (0.830 mg / g) and nylon (0.727 mg / g) still leading, although their adsorption capacities are significantly lower. This suggests that PVC and nylon have a natural affinity for lead but require surface degradation to maximize their adsorption potential.

[0041] In the case of zinc (Zn), polysiloxane (0.929 mg / g), vinyl (0.714 mg / g), and polypropylene (0.625 mg / g) in Set A exhibit the highest adsorption. In Set B, polysiloxane (0.609 mg / g) and vinyl (0.676 mg / g) still retain some adsorption capacity, albeit to a lesser extent. The system results confirm that weathering enhances zinc adsorption by creating additional microcracks and rough surfaces on the plastics.

[0042] Cadmium (Cd) adsorption also follows the weathering trend, with nylon (0.906 mg / g) and vinyl (0.587 mg / g) showing the highest cadmium retention in Set A. In Set B, nylon (0.573 mg / g) and vinyl (0.251 mg / g) exhibit lower adsorption values, confirming that surface changes due to weathering increase the binding efficiency of cadmium to polymers.

[0043] For cobalt (Co), nylon (0.736 mg / g), vinyl (0.480 mg / g), and polypropylene (0.452 mg / g) exhibit the highest adsorption in Set A. However, in Set B, nylon (0.529 mg / g) still leads, albeit with significantly lower adsorption values, which again supports the hypothesis that mechanical degradation improves adsorption performance by providing additional interaction sites for metal ions.

[0044] The adsorption of copper (Cu) follows the same trend as that of other metals, with nylon (0.762 mg / g), vinyl (0.493 mg / g), and LDPE (0.320 mg / g) showing the highest adsorption capacities in Set A. In Set B, nylon (0.452 mg / g) remains the most effective polymer for copper adsorption, followed by polysiloxane (0.262 mg / g) and LDPE (0.196 mg / g), although all values ​​are lower than those of their weathered counterparts.

[0045] The system results show that weathered plastic samples exhibit higher adsorption percentages for all heavy metals compared to unweathered samples. Among the tested metals, nickel shows the highest adsorption, with weathered polymers adsorbing 0.25% more than unweathered ones, followed by lead (0.85%), zinc (0.48%), cadmium (0.15%), cobalt (0.05%), and copper (0.15%). The increased surface roughness and microcracks in weathered plastics provide additional binding sites that enhance metal adsorption. This suggests that weathered plastics may play a more significant role in the accumulation and transport of heavy metals in the environment, particularly in aquatic ecosystems, where they can increase the risk of contamination to organisms and disrupt ecosystems.In addition, the larger surface area and roughness of weathered plastics can accelerate their degradation, which can lead to the release of adsorbed heavy metals into the environment.

Claims

[1] System for simulating the effect of weathering on the adsorption of heavy metals by microplastics, comprising: (a) a sample preparation module configured to select, clean and classify plastic samples into weathered and unweathered categories; (b) a weathering simulation module comprising an orbital shaker with a sand-water mixture and an abrasive treatment to imitate natural weathering processes; (c) a heavy metal exposure module for the preparation and maintenance of a controlled solution containing nickel (Ni), lead (Pb), zinc (Zn), cadmium (Cd), cobalt (Co) and copper (Cu) at predefined concentrations in order to expose plastic samples over a prolonged period of time; (d) a digestion and extraction module with nitric acid treatment and centrifugation to extract adsorbed heavy metals from the plastics; (e) an analytical evaluation module using atomic absorption spectroscopy (AAS) to quantify the degree of heavy metal adsorption on weathered and unweathered plastic surfaces; and (f) a comparative analysis module to evaluate the differences in adsorption between weathered and non-weathered plastics, to determine the adsorption efficiency of different polymers and to assess the environmental impacts of metal retention by microplastics. [2] The system of claim 1, wherein the weathering simulation module further comprises UV irradiation to replicate the effects of photodegradation on microplastics. [3] The system of claim 1, wherein the orbital shaker operates at adjustable speeds in the range of 100 to 300 rpm to simulate different degrees of mechanical erosion. [4] The system of claim 1, wherein the heavy metal exposure module maintains constant pH and temperature conditions to mimic real water or soil environments. [5] The system of claim 1, wherein the digestion and extraction module uses microwave-assisted acid digestion to improve the efficiency of heavy metal extraction from plastic surfaces. [6] The system of claim 1, wherein the analytical evaluation module is further configured to use inductively coupled plasma mass spectrometry (ICP-MS) in addition to AAS for more precise detection of heavy metal concentrations. [7] The system of claim 1, wherein the comparative analysis module applies machine learning algorithms to predict metal adsorption patterns based on the plastic type, weathering conditions, and environmental parameters. [8] The system of claim 1, wherein the system database stores adsorption data across multiple plastic compositions, enabling the creation of a predictive model for heavy metal retention and environmental impact assessment.