Aminated clay-polymer composite as soil amendment for stabilizing the short- and long-chain per- and poly-fluoroalkyl substances in contaminated soil.

Soils contaminated with per- and poly- fluoroalkyl substances (PFAS) require immediate remediation to protect the surrounding environment and human health. A novel animated clay-polymer composite was developed by applying polyethyleneimine (PEI) solution onto a montmorillonite clay-chitosan polymer composite. The resulting product, PEI-modified montmorillonite chitosan beads (MMTCBs) were characterized as an adsorptive soil amendment for immobilizing PFAS contaminants. The MMTCBs exhibited good efficiency to adsorb the PFAS, showing adsorption capacities of 12.2, 16.7, 18.5, and 20.8 mg g-1 for PFBA, PFBS, PFOA, and PFOS, respectively, which were higher than those obtained by granular activated carbon (GAC) (i.e., an adsorbent used as a reference). Column leaching tests demonstrated that amending soil with 10% MMTCBs resulted in a substantial decrease in the leaching of PFOA, PFOS, PFBA, and PFBS by 90%, 100%, 64%, and 68%, respectively. These reductions were comparable to the values obtained for GAC-modified soil, particularly for long-chain PFAS. Incorporating MMTCBs into the soil not only preserved the structural integrity of the soil matrix but also enhanced its shear strength (kPa). Conversely, adding GAC to the soil resulted in a reduction of the soil's mechanical properties.

Machine learning-based prediction and experimental validation of heavy metal adsorption capacity of bentonite.

As a natural adsorbent material, bentonite is widely used in the field of heavy metal adsorption. The heavy metal adsorption capacity of bentonite varies significantly in studies due to the differences in the properties of bentonite, solution, and heavy metal. To achieve accurate predictions of bentonite's heavy metal adsorption capacity, this study employed six machine learning (ML) regression algorithms to investigate the adsorption characteristics of bentonite. Finally, an eXtreme Gradient Boosting Regression (XGB) model with outstanding predictive performance was constructed. Explanation analysis of the XGB model further reveal the importance and influence manner of each input feature in predicting the heavy metal adsorption capacity of bentonite. The feature categories influencing heavy metal adsorption capacity were ranked in order of importance as adsorption conditions > bentonite properties > heavy metal properties. Furthermore, a web-based graphical user interface (GUI) software was developed, facilitating researchers and engineers to conveniently use the XGB model for predicting the heavy metal adsorption capacity of bentonite. This study provides new insights into the adsorption behaviors of bentonite for heavy metals, offering guidance and support for enhancing its application efficiency and addressing heavy metal pollution remediation.

Machine learning-based prediction of heavy metal immobilization rate in the solidification/stabilization of municipal solid waste incineration fly ash (MSWIFA) by geopolymers.

Geopolymer is an environmentally friendly solidification/stabilization (S/S) binder, exhibiting significant potential for immobilizing heavy metals in municipal solid waste incineration fly ash (MSWIFA). However, due to the diversity in geopolymer raw materials and heavy metal properties, predicting the heavy metal immobilization rate proves to be challenging. In order to enhance the application of geopolymers in immobilizing heavy metals in MSWIFA, a universal method is required to predict the heavy metal immobilization rate. Therefore, this study employs machine learning to predict the heavy metal immobilization rate in S/S of MSWIFA by geopolymers. A gradient boosting regression (GB) model with superior performance (R2 = 0.9214) was obtained, and a graphical user interface (GUI) software was developed to facilitate the convenient accessibility of researchers. The feature categories influencing heavy metal immobilization rate are ranked in order of importance as heavy metal properties > geopolymer raw material properties > curing conditions > alkali activator properties. This study facilitates the rapid prediction, improvement, and optimization of heavy metal immobilization in S/S of MSWIFA by geopolymers, and also provides a theoretical basis for the resource utilization of industrial solid waste, contributing to the environmental protection.

Large-scale laboratory investigation of the performance of a novel isolation particle layer for offshore final disposal sites.

The complex seabed conditions and ocean environment pose significant challenges to the material selection and construction of bottom liners for offshore final disposal sites. To overcome the challenges, this study proposed a novel isolation particle layer for offshore final disposal sites. The isolation particle was composed by salt-resistant bentonite coating material and cement core material (D10 was 10 mm in core diameter and 2 mm in coating thickness; D20 was 20 mm and 4 mm). Upon immersion in artificial seawater, the isolation particles underwent expansion, leading to the formation of the novel isolation particle layers with low hydraulic conductivity less than 1 × 10-7 cm/s and adsorption of heavy metals in bentonite interlayers. Large column tests showed that both D10 and D20 isolation particle layers exhibited remarkable swelling capacity and low hydraulic conductivity (4.3 × 10-9 cm/s and 2.6 × 10-8 cm/s) under 3 m seawater pressure. During one year of observation, water tank test demonstrated that both isolation particle layers displayed remarkable stability and low hydraulic conductivity of 2.73 × 10-10 cm/s and 8.36 × 10-10 cm/s with load. The maximum adsorption capacities of salt-resistant bentonite were 123.55 mg/g for Pb2+, 60.29 mg/g for Cd2+ and 54.22 mg/g for Cu2+. Both isolation particle layers exhibited a high removal rate of over 95 % for heavy metals in water tank tests. The large-scale laboratory tests indicated the significant potential of the novel isolation particle layer for offshore final disposal sites. Subsequently, a testing ocean site will be selected to further investigate its practical engineering performance.

Modified oyster shell powder with iron (II) sulfate heptahydrate to improve arsenic uptake in solution and in contaminated soils.

Arsenic is a metalloid whose presence can be due to natural or anthropological causes. It is considered as a toxic chemical that puts human health at high risk. In this study, we evaluated a novel modified oyster shell (MOS) that was coated with iron (II) sulfate heptahydrate using two different proportions through batch sorption experiments in an arsenic solution and in arsenic-contaminated soils. The arsenic solution was prepared using As(III)-standard solution. The arsenic contaminated soils were extracted from a contaminated site in Cheonan, South Korea, where the average arsenic concentration of the soil was reported as 136.28 mg/kg. Different doses of oyster shell and modified oyster were used to understand the effect of the addition of iron (II) sulfate heptahydrate via sorption batch experiments in solution and sorption tests in soils. The sorption tests were conducted with 50 g of contaminated soil; then, 150 g of soils was used for the pot cultivation tests, and finally, 150 g of contaminated soils was used for column percolation test. Through the experiments, the authors observed a comparable improvement of arsenic stabilization from 10 to 60% with the addition of iron (II) sulfate heptahydrate to oyster shell.

Red Mud-Amended Soil as Highly Adsorptive Hybrid-Fill Materials for Controlling Heavy Metal Sewage Seepage in Industrial Zone.

With the rapid development of urbanization, the problem of environmental pollution is becoming more and more serious. As a major pollutant, heavy metals have caused serious contamination in soil and groundwater. In order to prevent the diffusion of heavy metals in the soil from industrial sewage, the concept of hybrid-fill layer construction improved by red mud was proposed in this study. This study examines the adsorption capacities of lead and zinc ions and engineering characteristics on red mud-amended soils by direct shear, permeability, adsorption, desorption batch and column tests. Two mixing methods, full particle size displacement mixing and partial particle size displacement mixing, were adopted. The results showed that red mud effectively increased the adsorption capacity of soil to heavy metal ions, and the desorption rate of ions after adsorption was less than 3%, which had good anti-desorption ability. The optimum content of red mud in hybrid-fill material can be determined as 20%. The direct shear test showed that the internal friction angle of hybrid-fill material was 38.9°, and the cohesive force was 30.3 kPa, which met the engineering strength requirements of foundation materials. Based on the test results, red mud can be used as a barrier material to prevent heavy metal contamination in industrial sewage from diffusion, which controls not only heavy metal contamination but also consumes industrial by-products.

Metabolome and transcriptome analyses of plants grown in naturally attenuated soil after hydrogen fluoride exposure.

Accidental chemical leaks and illegal chemical discharges are a global environmental issue. In 2012, a hydrogen fluoride leak in Gumi, South Korea, killed several people and contaminated the environment. This leak also led to a significant decline in crop yield, even after the soil concentration of hydrogen fluoride decreased to below the standard level following natural attenuation. To determine the cause of this decreased plant productivity, we designed direct and indirect exposure tests by evaluating the metabolome, transcriptome, and phenome of the plants. In an indirect exposure test, soil metabolomics revealed downregulation of metabolites in vitamin B6, lipopolysaccharide, osmolyte, and exopolysaccharide metabolism. Next-generation sequencing of the plants showed that ABR1 and DREB1A were overexpressed in response to stress. Plant metabolomics demonstrated upregulation of folate biosynthesis and nicotinate and nicotinamide metabolism associated with detoxification of reactive oxygen species. These results demonstrate impaired metabolism of soil microbes and plants even after natural attenuation of hydrogen fluoride in soil. The novel chemical exposure testing used in this study can be applied to identify hidden damage to organisms after natural attenuation of chemicals in soil, as well as biomarkers for explaining the decline in yield of plants grown in soil near pollutant-emitting industrial facilities.

Removal of lead ions from wastewater using lanthanum sulfide nanoparticle decorated over magnetic graphene oxide.

In this study, the new lanthanum sulfide nanoparticle (La2S3) was synthesized and incorporated onto magnetic graphene oxide (MGO) sheets surface to produce potential adsorbent (MGO@LaS) for efficient removal of lead ions (Pb2+) from wastewater. The synthesized MGO@LaS adsorbent was characterized using Fourier transform infrared spectroscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. The effective parameters on the adsorption process including solution pH (~5), adsorbent dosage (20 mg), contact time (40 min), initial Pb2+ concentration and temperature were studied. The removal efficiency was obtained >95% for lead ions at pH 5 with 20 mg adsorbent. To validate the adsorption rate and mechanism, the kinetic and thermodynamic models were studied based on experimental data. The Langmuir isotherm model was best fitted to initial equilibrium concentration with a maximum adsorption capacity of 123.46 mg/g. This indicated a monolayer adsorption pattern for Pb2+ ions over MGO@LaS. The pseudo-second-order as the kinetic model was best fitted to describe the adsorption rate due to high R2 > 0.999 as compared first-order. A thermodynamic model suggested a chemisorption and physisorption adsorption mechanism for Pb2+ ions uptake into MGO@LaS at different temperatures; ΔG° < -5.99 kJ mol-1 at 20 °C and ΔG° -18.2 kJ mol-1 at 45 °C. The obtained results showed that the novel nanocomposite (MGO@LaS) can be used as an alternative adsorbent in wastewater treatment.

Application of ZnO-Nd Nano-Photocatalyst for the Reactive Red 198 Dye Decolorization in the Falling-Film Photocatalytic Reactor.

A large amount of Reactive red 198 (RR198) is released yearly into the environment. RR198 is toxic for human and aquatic creatures; therefore, it should be removed from wastewater before releasing into the environment. In this study, the nano ZnO-Nd -photo-catalyst for the first time was synthesized by the combustion method. First, the physical characteristics of the generated nano photocatalyst were evaluated using FESEM, XRD, Bandgap calculation, and FTIR analysis. Then, the ZnO-Nd nano-photocatalyst was suspended into the contaminated water with RR198 dye in a falling-film photocatalytic reactor. The effects of parameters such as the amount of H2O2, catalyst dose, pH, and initial concentration of dye were investigated during the experiments. Finally, the decolorization process with the falling-film photocatalytic reactor was optimized using response surface methodology (RSM). The physical characteristics showed that the average particle size of the synthesized ZnO-Nd was 40 nm. Doping ZnO with Nd reduced the photocatalyst energy bandgap by 14%. The results indicated that the optimum amount of catalyst dose and pH level was 0.1 g/L and 5, respectively. The simultaneous usage of H2O2 and ZnO-Nd with an H2O2/dye ratio of two increased dye removal performance by 90%. The results demonstrated that the developed equations can be applied to predict the performance of the falling-film photoreactor. This study showed that using the nano ZnO-Nd photocatalyst in a falling-film photocatalytic reactor under optimum operating conditions is an appropriate way to remove RR198 from water.

Facemasks: A Looming Microplastic Crisis.

Single-use disposable facemasks have been used as a preventive measure against the ongoing COVID-19 pandemic. However, many researchers have found evidence that these facemasks are being dumped into lakes, rivers, and open garbage dumps. Facemasks have the potential of releasing microplastic fibers into the environment; a phenomenon that has been poorly investigated. Moreover, microplastic fibers composed of plastics have the potential of affecting the flora and fauna of many ecosystems. In this preliminary study, we investigate how many microplastic fibers had been released to the water by KF-AD, KF94, surgical, and FFP1 standard facemasks, which are the most widely available facemask standards in South Korea. The waterbody in our research was mechanically agitated for 24, 48, and 72 h. Findings showed that most of the layers of facemasks are composed of polypropylene. The surgical and KF94 standard facemasks released the highest number of microplastic fibers. Furthermore, under our research conditions, a single facemask can release at least 47 microplastic fibers per day (e.g., KF-AD standard mask), which can lead to the release of at least 1381 million microplastic fibers per day in total in South Korea if 70% of the urban population uses a single mask every day. Moreover, the released microplastic fibers significantly increased when the agitation time extended from 24 to 48 h. This finding suggests that the number of released microplastic fibers is likely to increase drastically.

Oyster Shell Powder, Zeolite and Red Mud as Binders for Immobilising Toxic Metals in Fine Granular Contaminated Soils (from Industrial Zones in South Korea).

Low-cost absorbent materials have elicited the attention of researchers as binders for the stabilisation/solidification technique. As, there is a no comprehensive study, the authors of this paper investigated the performance of Oyster shell powder (OS), zeolite (Z), and red mud (RM) in stabilising heavy metals in three types of heavy metal-contaminated soils by using toxicity characteristic leaching procedure (TCLP). Samples were collected from surroundings of an abandoned metal mine site and from military service zone. Furthermore, a Pb-contaminated soil was artificially prepared to evaluate each binder (100× regulatory level for Pb). OS bound approximately 82% of Pb and 78% of Cu in real cases scenario. While Z was highly effective in stabilizing Pb in highly polluted artificial soil (>50% of Pb) at lower dosages than OS and RM, it was not effective in stabilising those metals in the soils obtained from the contaminated sites. RM did not perform consistently stabilising toxic metals in soils from contaminated sites, but it demonstrated a remarkable Pb-immobilisation under dosages over than 5% in the artificial soil. Further, authors observed that OS removal efficiency reached up to 94% after 10 days. The results suggest that OS is the best low-cost adsorbent material to stabilize soils contaminated with toxic metals considered in the study.

High efficiency removal of heavy metals using tire-derived activated carbon vs commercial activated carbon: Insights into the adsorption mechanisms.

In this study, activated carbon was derived from pulverized waste tires using carbonization and chemical activation techniques. Single and competitive batch adsorption experiments for the removal of three synthetic heavy metal ions (Pb2+, Cu2+ and Zn2+) from an aqueous solution were performed to benchmark the efficiency of the Tire-derived Activated Carbon (TAC) in comparison to that of commercial activated carbon (CAC), which was used as the reference material. The sorbents physicochemical properties with corresponding adsorption mechanisms were evaluated by different experimental techniques. TAC exhibited great potential to adsorb heavy metals, with monolayer adsorption capacities as high as 322.5, 185.2, and 71.9 mg g-1 for Pb2+, Cu2+ and Zn2+, respectively, which were significantly higher than the adsorption capacities exhibited by CAC, which were 42.5, 15.0, and 14.0 mg∙g-1 for Pb2+, Cu2+ and Zn2+, respectively. Competitive adsorption results demonstrated the adsorption ability of sorbents is restricted by presence of other ions, and was decreased compared to the single sorption. Sorption kinetics data, with better fit to the pseudo-second order kinetics model, revealed that TAC had faster sorption rate in comparison to CAC. The adsorption capacities of TAC and CAC were reduced to half of their initial capacities after three successive adsorption-desorption cycles. Zeta potential, FT-IR, and XPS analyses revealed that electrostatic attraction and surface complexation mechanisms, as two metal-adsorbing mechanisms, were more influential for TAC. For CAC, a higher cation exchange capacity (CEC) value indicated that the removal of heavy metals by ion exchange was the predominant mechanism.

BTEX and heavy metals removal using pulverized waste tires in engineered fill materials.

In this study, the potential of pulverized waste tires (PWTs), either on their own or mixed with soil (well graded sand), to act as adsorptive fill materials was evaluated by conducting laboratory tests for accessing their adsorption and geotechnical properties. PWT (0, 5, 10, 15, 25, and 100 wt%) was mixed with soil to evaluate the removal of benzene, toluene, ethylbenzene, and xylene (BTEX) components and two heavy metal ions (Pb2+ and Cu2+). Adsorption batch tests were performed to determine the equilibrium sorption capacity of each mixture. Subsequently, compaction, direct shear, and consolidation tests were performed to establish their geotechnical properties. The results showed that BTEX had the strongest affinity based on the uptake capacity by the soil-PWT mixtures. The adsorption of BTEX increased for greater PWT content, with pure PWT having the highest adsorption capacity toward BTEX removal: uptake capacities for xylene, ethylbenzene, toluene, and benzene were 526, 377, 207 and 127 µg/g sorbent, respectively. Heavy metal removal was increased by increasing the amount of PWT up to 10 wt%, and then decreased beyond this ratio. Compacted soil-PWT mixtures comprising 5-25 wt% PWT have relatively low dry unit weight, low compressibility, adequate shear capacity for many load-bearing field applications, and satisfactory adsorption of organic/inorganic contaminants, such that they could also be used as adsorptive fill materials.

Development of a novel base liner material for offshore final disposal sites and the assessment of its hydraulic conductivity.

In the process of landfilling, leachates resulting from the waste landfill are likely to cause secondary environmental pollution, and installation of a basal liner is essential under a landfill site to block and reduce permeation of leachate flowing into the subsurface environment. The research aims to develop a salt-resistant bentonite and a novel base liner material for offshore waste disposal. The liner materials consist of core materials and coating materials in which mixtures of bentonite, sepiolite, and guar gum were used to overcome the shortcomings in bentonite to realise a high water-resistance and a permeability coefficient of below 1.0 × 10-7 cm/s under saline water conditions. The optimal mixing ratio of bentonite, sepiolite, and guar gum was confirmed as 76:19:5 by conducting drying shrinkage cracking tests, free swelling tests, and hydraulic conductivity tests. The hydraulic conductivities of spherical particles, as measured in a rigid-wall permeameter and a flexible-wall permeameter, were less than 1.0 × 10-7 cm/s under saline water conditions. The compressive properties of spherical particles were evaluated through triaxial compression testing. The engineering characteristics of the liner material were studied in the present research, but the long-term biodegradation characteristics of polymer additives were also important, yet remained unclear. The long-term biostability of the additives, and its effect on basal liner performance should be evaluated in future research.

A new approach for modeling flux variation in membrane filtration and experimental verification.

It is important to model flux variation during the membrane filtration process, particularly in the early stage of filtration where severe fouling causes rapid flux decay in a short period of time. The objective of this study was to develop a combined fouling mathematical model based on energy head loss principle for prediction of flux variation in the membrane filtration. The complete-cake model was employed in the model in order to describe the loss of membrane available area due to pore clogging, while, the classical cake model was used for cake filtration. A new dimensionless parameter, namely the filter number (FN) was proposed in this study to account for the unmeasurable properties of the membrane in the model. The application of the proposed model was tested and compared with the existing models using experimental data for the filtration of wastewater sludge, microalgae suspension and sodium alginate solution with different membranes and pressures. The results showed that the flux calculated values of the new model had good agreements with the experimental data under different conditions. According to statistical analyses, the model improved the representing accuracy of flux variation in the early stage of filtration. In addition, the model provides better performance and efficiency in comparison to the existing models for high flux operations which is more conventionally applied in the industry and is expected to be more in the future.

Current Scenario of the Tehran Municipal Solid Waste Handling Rules towards Green Technology.

This study aims to study the waste management process and recycling of municipal waste in Tehran. Currently, Kahrizak is the defined landfill area which collects the waste generated from 22 districts of Tehran. The organic wastes undergo to the windrow composting method in order to manage the partial of the waste generated in the city. Samples from the compost pile generated in Kahrizak were examined to evaluate its fertilizer value to be used further by the farmers. The results show that the obtained compost does not reach the acceptable quality to be used further in agriculture, due to lack of homogeneity, aeration and presence of heavy metals. Overall, it has been concluded that, due to the improper waste segregation and management prior to sending to landfill and presence of non-organic materials such as hazardous metals and medical wastes, causes difficulties in proper waste management, implementation and producing high quality compost. Based on this study the existence of stakeholders, society, economy and proper handling rules can effectively improve the waste management system in the country and leads to the sustainable green environment.

Phytoremediation potential and control of Phragmites australis as a green phytomass: an overview.

Phragmites australis (common reed) is one of the most extensively distributed emergent plant species in the world. This plant has been used for phytoremediation of different types of wastewater, soil, and sediments since the 1970s. Published research confirms that P. australis is a great accumulator for different types of nutrients and heavy metals than other aquatic plants. Therefore, a comprehensive review is needed to have a better understanding of the suitability of this plant for removal of different types of nutrients and heavy metals. This review investigates the existing literature on the removal of nutrients and heavy metals from wastewater, soil, and sediment using P. australis. In addition, after phytoremediation, P. australis has the potential to be used for additional benefits such as the production of bioenergy and animal feedstock due to its specific characteristics. Determination of adaptive strategies is vital to reduce the invasive growth of P. australis in the environment and its economic effects. Future research is suggested to better understand the plant's physiology and biochemistry for increasing its pollutant removal efficiency.

The effects of surfactants (sodium dodecyl sulfate, triton X-100 and cetyl trimethyl ammonium bromide) on the dewaterability of microalgae biomass using pressure filtration.

The application of pressure filtration in microalgae harvesting requires chemical pretreatment in order to reduce membrane fouling and to increase water flux. Surfactants have shown potential to enhance microalgae dewaterability by charge neutralization, bridging and releasing extracellular polymeric substances (EPS) and bound water. In this study, the effect of three surfactants including anionic sodium dodecyl sulfate (SDS), non-ionic triton X-100 and cationic cetyl trimethyl ammonium bromide (CTAB) on the dewaterability of Chlamydomonas sp. was investigated. Filtration fluxes and biomass concentrations were used to evaluate the microalgae dewaterability. Based on the results, SDS and Triton X-100 had a negative effect on the dewaterability of microalgae biomass. However, CTAB improved the dewaterability by decreasing the reversible and irreversible fouling resistance. The optimum dosage of CTAB was found to be 1500 mg/L, and resulted in 95.8% and 140% improvement on average water flux and biomass recovery efficiency, respectively.

Optimization of aluminium recovery from water treatment sludge using Response Surface Methodology.

For decades, water treatment plants in Malaysia have widely employed aluminium-based coagulant for the removal of colloidal particles in surface water. This generates huge amount of by-product, known as sludge that is either reused for land applications or disposed to landfills. As sludge contains high concentration of aluminium, both can pose severe environmental issues. Therefore, this study explored the potential to recover aluminium from water treatment sludge using acid leaching process. The evaluation of aluminium recovery efficiency was conducted in two phases. The first phase used the one factor at a time (OFAT) approach to study the effects of acid concentration, solid to liquid ratio, temperature and heating time. Meanwhile, second phase emphasized on the optimization of aluminium recovery using Response Surface Methodology (RSM). OFAT results indicated that aluminium recovery increased with the rising temperature and heating time. Acid concentration and solid to liquid ratio, however, showed an initial increment followed by reduction of recovery with increasing concentration and ratio. Due to the solidification of sludge when acid concentration exceeded 4 M, this variable was fixed in the optimization study. RSM predicted that aluminium recovery can achieve 70.3% at optimal values of 4 M, 20.9%, 90 °C and 4.4 h of acid concentration, solid to liquid ratio, temperature and heating time, respectively. Experimental validation demonstrated a recovery of 68.8 ±â€¯0.3%. The small discrepancy of 2.2 ±â€¯0.4% between predicted and validated recovery suggests that RSM was a suitable tool in optimizing aluminium recovery conditions for water treatment sludge.

Microplastics pollution in different aquatic environments and biota: A review of recent studies.

Microplastics (MPs) are generated from plastic and have negative impact to our environment due to high level of fragmentation. They can be originated from various sources in different forms such as fragment, fiber, foam and so on. For detection of MPs, many techniques have been developed with different functions such as microscopic observation, density separation, Raman and FTIR analysis. Besides, due to ingestion of MPs by wide range of marine species, research on the effect of this pollution on biota as well as human is vital. Therefore, we comprehensively reviewed the occurrence and distribution of MPs pollution in both marine and freshwater environments, including rivers, lakes and wastewater treatment plants (WWTPs). For future studies, we propose the development of new techniques for sampling MPs in aquatic environments and biota and recommend more research regarding MPs release by WWTPs.