The rapid and silent emergence of microplastics (MPs) in the environment has recently become a global problem with more and more studies are showing the harmful effects of MPs on different ...ecosystems. The aim of this study was to investigate the presence of MPs in agricultural soils, wastewater effluents and sewage sludge in Mauritius. The soil samples were collected randomly from three different agricultural lands which have been used for conventional agriculture for more than 25 years. Wastewater effluents and sewage sludge were collected once, using the grab sampling method, from three main operating wastewater treatment plants (WWTP) across the island and were analysed in triplicate. MPs were extracted using the flotation technique, followed by hydrogen peroxide digestion. The abundance of MPs was found to be 320.0 ± 112.2 and 420.0 ± 244.0 particles.kg-1 in shallow and deep soils, respectively, out of which 42.4% and 95.8% were less than 1 mm in size, respectively. Site 3 had the highest abundance of MPs due to cumulated plastic debris dumped on the field. In addition, the average MPs concentration in sewage sludge and in wastewater effluents were 14,750 ± 8612.9 particles.kg-1 and 276.3 ± 137.3 particles.L-1, respectively, whereby 90% of the MPs were less than 0.5 mm in size. WWTP 1 had the largest share of MPs in both sewage sludge and wastewater effluents. The attenuated total reflection Fourier transform infrared spectroscopy revealed that polypropylene (fibres, fragments, and flakes) was in abundance in agricultural soil samples by 56.26%, while in WWTP polyamide (fibres) was predominant by 88.85%. The findings of this preliminary study confirmed the presence of MPs in Mauritian lands, wastewater effluents and sewage sludge and therefore provide salient data to advocate for subsequent research on MPs.
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•An average of 231 microplastics/kg was found in agricultural land near landfill.•96% of microplastics (<1 mm) were found in deeper layers of agricultural soils.•More than 50% of microplastics identified in agricultural land was polypropylene.•An average of 99 microplastics/L was found in the wastewater effluents.•More than 80% of microplastics identified in WWTPs corresponded to microfibres.
•Micropollutants of 216 were detected in effluents from 46 WWTPs across China.•The exposure and hazard potential of pollutants were defined based on multivariate analysis.•PI method was proposed to ...prioritize multi-class micropollutants in effluents of WWTPs.•Priority criteria involved concentration, detection rate, persistence, bioaccumulation and toxicity.•Pollutants with high PI scores mainly included POPs and their alternatives.
Identifying priority pollutants in wastewater treatment plant (WWTP) effluents is crucial for optimizing monitoring efforts, improving regulations, and developing targeted mitigation strategies. Despite the presence of numerous trace organic pollutants in WWTP effluents, a comprehensive prioritization scheme is lacking, hindering effective control. This study screened 216 micropollutants, including pharmaceuticals, pesticides, and industrial chemicals, which had been detected in effluents from 46 WWTPs across China. A multi-criteria prioritization method was developed, considering exposure potential based on median concentrations and detection frequencies, as well as hazard potential determined by persistence, bioaccumulation, in vitro toxicity, and in vivo toxicity. Pollutants with low exposure or hazard potential were filtered out, and a priority index was calculated to rank the remaining 59 substances. The top 15 priority pollutants included regulated persistent organic pollutants like perfluorooctanoic acid and their alternatives such as perfluorobutane sulfonate, pesticide transformation products, and emerging contaminants such as bisphenol A, which are not currently regulated in WWTP effluents. This study provides a systematic approach to identify priority pollutants and generates a guiding framework for monitoring, regulation, and control of both well-recognized and overlooked contaminants in WWTP effluents.
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Antibiotics have been frequently detected in the aquatic environment and are of emerging concern due to their adverse effect and potential of inducing antibiotic resistance. In this study, we ...developed an UV/pre-magnetized Fe0/H2O2 process (UV/pre-Fe0/H2O2) valid for neutral pH conditions, which could remove sulfamethazine (SMT) completely within only 30 min and enhance 1.8 times of SMT removal. Meanwhile, this process demonstrated outstanding mineralization capability with the TOC removal of 92.1%, while for UV/H2O2 and UV/Fe0/H2O2 system it was 53.9% and 72.1%, respectively. Better synergetic effect between UV irradiation and pre-Fe0/H2O2 system was observed, and the value of synergetic factor was 6.3 in the presence of both ions and humic acid, which was much higher than that in deionized water (4.4), humic acid (5.5) and ions (1.5). Moreover, the process could efficiently remove various antibiotics (800 μg L-1 oxytetracycline (OTC); 800 μg L-1 tetracycline (TC); 400 μg L-1 sulfadiazine (SD) and 400 μg L-1 SMT) in the secondary wastewater effluent. After optimization of Fe0 and H2O2 dosage, these antibiotics could be removed within 10 min (kapp (103) = 288.6 min-1) with a very low treatment cost of 0.1 USD m-3, and the EE/O value was only 1.22 kWh m-3. Compared with O3, UV/Fe2+/PDS, VUV/UV/Fe2+ and other US-based processes, the degradation rates by this process could enhance as high as 22.3 folds while the treatment cost or EE/O value could reduce greatly. Therefore, UV/pre-Fe0/H2O2 process is promising and cost-effective for the treatment of antibiotics in secondary wastewater effluents.
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•UV/pre-Fe0/H2O2 process enhanced degradation and mineralization for antibiotics.•Higher synergetic effect (6.3) between UV irradiation and pre-Fe0/H2O2 was observed.•Typical antibiotics could be efficiently removed with a low treatment cost of 0.1 USD m−3.•This process was more cost-effective than other AOPs (e.g., O3, UV/Fe2+/PDS, VUV/UV/Fe2+).•It is promising and cost-effective for the treatment of antibiotics in secondary effluents.
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•A selective electrodialysis reactor was developed for nutrients recovery and desalination.•HPO42− and NO3− were separated and concentrated in different compartments of the SED ...system.•The simultaneous removal of Cl−, NO3− and HPO42− indicated a well desalination performance.•A mathematics model was developed to simulate the variation of current.
Recovering resources, especially nutrients and water, from biologically treated secondary effluent, which in line with the concept of zero liquid discharge, has attracted increasing interests. In this study, a selective electrodialysis (SED) was developed to separate and recover the nitrogen and phosphorus nutrients and enforce desalination during secondary effluents treatment under low applied voltages. The SED system performance as well as current efficiency and energy consumption were investigated under different number of ion exchange membrane trios, applied voltages and flow rates. Nitrate could be reconcentrated to 40.64mg-NL−1 in brine compartments while the phosphate was retained by a monovalent anion exchange membrane and concentrated to 21.2mg-PL−1 in product compartments. The conductivities of feed compartments were all below 2µS/cm after treatment, indicating a well desalination performance of the SED system. The current efficiency was obtained to be lower under a higher voltage, and a mathematical fitting of current was developed to confirm the existence of water dissociation under higher voltages. The SED with more ion exchange membrane trios proved to be able to perform an effective desalination under advantageous electricity consumption conditions. With the capability to reconcentrate nutrients and simultaneously realize zero liquid discharge of secondary wastewaters, the examined SED treatment technology has a potential for practical nutrient recovery and sustainable water reuse.
Pulp and paper industries (PPI) generate an enormous amount of wastewater which are heavily loaded with a variety of pollutants. Aim of this study to evaluate different physico-chemical pollution ...parameters and the occurrence of toxic elements in the wastewater of four PPI located in the Utter Pradesh and Uttarakhand regions of India. Results revealed that the physico-chemical analysis of discharged wastewater from selected four PPI showed high pollution parameters along with heavy metals. Industry-1 has containing with high pH (8.03 ± 0.01), BOD (9364± 170), COD (26548± 234), EC (1756 ± 67.24), TS (3156 ± 136), TDS (1954 ± 2.14), and TSS (156 ± 1.03). Industry- 2 has containing with high pH (8.06 ± 0.03), BOD (8634 ± 104), COD (56872 ± 211), EC (1896 ± 23.01), TS (4365 ± 120), TDS (1634 ± 31.49), and TSS (124 ± 1.00). Industry- 3 have containing with high pH (8.05 ± 0.02), BOD (8567 ± 214), COD (35478 ± 234), EC (6479 ± 124.05), TS (2456 ± 187), TDS (1354 ± 31.02), TSS (136 ± 1.01), and Industry- 4 have containing with high pH (8.07 ± 0.05), BOD (7136 ± 151), COD (26324 ± 348), EC (1531 ± 91.05), TS (3147 ± 171), TDS (2465 ± 33.15), and TSS (248 ± 2.31) were above the permissible limit. The conclusions of this study, the PPI wastewater should be treated at a tertiary stage before discharged in environmental.
Research in the United States evaluating ecotoxic risk to receiving waters posed by contaminants occurring in wastewater discharges typically has focused on measurements of pharmaceuticals and ...personal care products (PPCPs), with limited evaluations of UV filters and phenylpyrazole and neonicotinoid pesticides. In this study, concentrations of 5 representative pharmaceuticals, 11 pesticides or pesticide degradation products, and 5 ultraviolet filters were measured in 24 h composite samples of six wastewater discharges representing ∼70% of the total wastewater discharged to San Francisco Bay during the summer and fall of 2021. No significant difference was observed between concentrations measured on weekdays vs. weekends. A hydrodynamic model of San Francisco Bay was used to estimate annual average dilution factors associated with different subembayments. With and without considering dilution effects, Risk Quotients were calculated using the 90th percentile of measured concentrations in wastewater effluents and threshold concentrations associated with ecotoxicity. Risk Quotients were highest for the neonicotinoid pesticide, imidacloprid, and exceeded ecotoxicity thresholds in the lower South Bay by a factor of 2.4, even when considering dilution. Compared to commonly measured pharmaceuticals, Risk Quotients for imidacloprid were higher than those for carbamazepine, trimethoprim and diclofenac, and comparable to those for propranolol and metoprolol. Risk Quotients for the pesticide, fipronil, and the UV filter, oxybenzone, were higher than for carbamazepine. The results highlight the need to incorporate pesticides and UV filters with high Risk Quotients into studies in the United States evaluating ecotoxic risk associated with contaminants in municipal wastewater discharges.
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•Ultraviolet filters, pesticides, pharmaceuticals measured in 6 wastewater effluents.•No difference in concentrations observed between weekday and weekend.•Imidacloprid featured the highest ecotoxic risk quotient among 21 contaminants.•Risk quotients for oxybenzone and fipronil were comparable to commonly measured PPCPs.
•EHPi method was proposed to integrate characteristics of pollutants in wastewater.•34 typical pollutants in effluents were ranked by EHPi scores at a national level.•Pollutants that have synergistic ...effects with other pollutants were also identified.•Pollutants with high EHPi scores showed spatial differences.
The identification of the priority control sequence of pollutants in effluents of wastewater treatment plants (WWTPs) has important implications for the management of water quality. This study chose 34 typical pollutants based on their representativeness and detection rates in municipal wastewater. The occurrence frequency and concentration of these pollutants in 168 Chinese WWTP effluents were measured at the national level. The data on in vitro toxicity (67 assays) and in vivo toxicity (216 species) for target pollutants were obtained from the public toxicity database and our experimental data. An environmental health prioritization index (EHPi) method was proposed to integrate the occurrence frequency, concentration, removal rate, and in vitro and in vivo toxicity to determine the priority control sequence of target pollutants. Ethynyl estradiol, 17β-estradiol, estrone, diclofenac, and atrazine were the top 5 pollutants identified by the EHPi score. Several pollutants with high EHPi scores showed spatial differences. Besides the EHPi method which was from the single pollutant perspective, the combined toxicity of pollutants (300 pairs of binary combinations) was also measured based on in vitro toxicity assays to evaluate the key pollutants from the pollutant-pollutant interacting perspective. The pollutants (such as ofloxacin and acetaminophen) that could have significant synergetic effects with many other pollutants are worthy of prior attention. This study shed new light on the identification of the priority control sequence of pollutants in WWTP effluents. The results provide meaningful data for the effective management and control of wastewater water quality.
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•Isotope-based assessment of water cycling in a lowland, peri-urban catchment.•Higher stream evaporation and depletion of groundwater storage after two dry years.•Stream flow ...dominated by groundwater and waste water effluents.•Limited influence of precipitation and urban storm runoff.•Overlapping isotopic signatures in effluent and groundwater increased uncertainty in water source and age assessment.
In peri-urban catchments where treated wastewater effluents are released into surface waters, knowledge of water sources and partitioning is important for mitigating water quality impacts, particularly during warm and dry periods with low discharge rates. Useful tools for the identification of water sources and flow paths under different wetness conditions are isotope tracers. However, very few studies have been carried out so far in urbanized catchments with complex land use distributions where natural headwaters interact with engineered components, e.g. effluent discharge. We undertook spatio-temporal sampling of isotopes, combined with water quality measurements, to complement climatic and hydrometric data across the 220 km2 peri-urban Erpe catchment near Berlin and assess seasonal changes in water sources during two exceptionally warm and dry years (2018 and 2019). The study showed a deterioration of water quality downstream of two municipal wastewater treatment plants; and the depletion of groundwater storage, along with isotopic enrichment of the stream, in summer 2019 (the second consecutive year with above-average temperatures and marked precipitation deficits). Streamflow in the upper reaches of the catchment was dominated by groundwater-fed tributaries in winter, but became increasingly dominated by wastewater in summer. In the lower catchment, flows were dominated by effluent from a large wastewater treatment plant, especially in summer. Young water from precipitation and urban storm runoff accounted for < 10 % of streamflow, despite the catchment being ~ 20 % urban. Similarities in the composition of wastewater and other runoff sources resulted in high uncertainties in end member separation and highlight the need for monitoring of other tracers to better characterize water impacts. Given climate change projections for the region are for drier, warmer summers, wastewater is likely to become a more dominant component of streams, which may have implications for environmental quality and ecosystem services.
•A complex mixture of neuroactive pharmaceuticals accumulated in the brain and plasma of effluent-exposed roach.•Bioconcentration factors of the pharmaceuticals were 3-40 fold higher in brain ...compared with blood plasma•Fish plasma concentrations of pharmaceuticals were 33-5714 fold below human therapeutic plasma concentrations•Disruption in neurotransmitter concentrations were observed in brain regions of effluent-exposed fish.
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Fish can be exposed to a variety of neuroactive pharmaceuticals via the effluent discharges from wastewater treatment plants and concerns have arisen regarding their potential impacts on fish behaviour and ecology. In this study, we investigated the uptake of 14 neuroactive pharmaceuticals from a treated wastewater effluent into blood plasma and brain regions of roach (Rutilus rutilus) after exposure for 15days. We show that a complex mixture of pharmaceuticals including, 6 selective serotonin reuptake inhibitors, a serotonin-noradrenaline reuptake inhibitor, 3 atypical antipsychotics, 2 tricyclic antidepressants and a benzodiazepine, concentrate in different regions of the brain including the telencephalon, hypothalamus, optic tectum and hindbrain of effluent-exposed fish. Pharmaceuticals, with the exception of nordiazepam, were between 3–40 fold higher in brain compared with blood plasma, showing these neuroactive drugs are readily uptaken, into brain tissues in fish. To assess for the potential for any adverse ecotoxicological effects, the effect ratio was calculated from human therapeutic plasma concentrations (HtPCs) and the measured or predicted fish plasma concentrations of pharmaceuticals. After accounting for a safety factor of 1000, the effect ratios indicated that fluoxetine, norfluoxetine, sertraline, and amitriptyline warrant prioritisation for risk assessment studies. Furthermore, although plasma concentrations of all the pharmaceuticals were between 33 and 5714-fold below HtPCs, alterations in serotonin, glutamate, acetylcholine and tryptophan concentrations were observed in different brain regions of effluent-exposed fish. This study highlights the importance of determining the potential health effects arising from the concentration of complex environmental mixtures in risk assessment studies.
•Lignite and coconut powdered activated carbons were modified with magnetic iron oxide.•This facilitates magnetic separation, inductive regeneration and reuse of the carbon.•Iron oxide was integrated ...via infiltration or surface deposition synthesis method.•Infiltrated lignite had the best overall regeneration & organics removal performance.•It maintained high adsorption efficiency for 28 micropollutants over 5 reuse cycles.
This work introduces a new sustainable alternative of powdered activated carbon (PAC) - magnetically harvestable and reusable after regeneration via inductive heating - for the adsorptive removal of organic micropollutants (OMP) from secondary wastewater effluents. For this purpose, two commercial PACs - lignite “L” (1187 m2/g) and coconut “C”-based (1524 m2/g) - were modified with magnetic iron oxide following two different synthesis approaches: infiltration (“infiltr”) and surface deposition (“depos”) route. The resulting magnetic powdered activated carbons (mPAC) and their precursor PACs were fully characterized before application. The iron oxide content of the modified “L” and “C” samples was ∼30 % and ∼20 %, respectively. Iron oxide gives the PAC beneficial magnetic properties for easy magnetic separation and simultaneously acts as an inductively heatable agent for the carbon regeneration. The infiltrated samples displayed better inductive heating performance and regeneration than their deposited counterparts. Tests with real wastewater showed fast adsorption kinetics of the organic load following the pseudo-second-order kinetic model. Adsorption isotherms were compliant with the Freundlich isotherm model. Sample “L-infiltr” had the best overall adsorption performance throughout 5 reuse cycles when intermediately inductively regenerated (<3 % drop in organics removal per cycle with intermediate regeneration vs. ∼10 % drop per cycle without regeneration). The treated supernatant was additionally tested for 31 representative organic micropollutants and their transformation products (pharmaceuticals, personal care products, industrial chemicals, etc.), where 26 OMPs had consistently high removal (>85 %) throughout 5 cycles with intermediate regeneration and for 28 OMPs the total adsorption efficiency dropped by <5 % after 5 cycles.
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