Search Results (99)

Surveillance of swine influenza A virus (swIAV) traditionally focuses on respiratory matrices, yet emerging evidence suggests that fecal shedding and secondary environmental contamination may also contribute to viral dissemination. In this study, we collected and analyzed nasal, rectal, environmental, milk, and colostrum samples from naturally infected pigs in a commercial farm in Minas Gerais, Brazil. IAV RNA was detected in 25% of samples, including 42% from asymptomatic animals, with nasal swabs showing higher detection rates (30%) than rectal swabs (20%), though rectal Ct values were consistently higher, indicative of lower viral loads. We successfully isolated viable viruses from feces and effluent samples. Whole-genome sequencing revealed co-circulation of enzootic pH1N1 clade #2 (HA) and pN1 clade #4 (NA), alongside human-origin H3N2 sequences clustering within clade 3C.2a1b.2a.2a.1, and N2 segments related to pre-3C human lineages from 2001 to 2002. Phylogenetic and p-distance analyses support both recent reverse zoonosis and historical transmission events. Detection of complete HA/NA sequences from rectal swabs and treated effluent further emphasizes the surveillance value of non-respiratory matrices. The integration of respiratory and fecal/environmental sampling appears important to achieve more comprehensive IAV monitoring in swine herds and may have significant implications for One Health strategies in Brazil and beyond. Full article

Fenton oxidation can contribute to meeting effluent standards for COD in actual wastewater treatment plant effluents. However, Fenton oxidation is prone to produce iron sludge waste. The application of heterogeneous Fenton-like systems based on Fenton iron mud carbon in wastewater treatment plants is essential for Fenton iron mud reduction and recycling. In this study, a Fenton iron mud carbon catalyst/Ferrate salts/H₂O₂ (FSC/Fe(VI)/H₂O₂) system was developed to remove chemical oxygen demand (COD) from secondary effluents at the pilot scale. The results showed that the FSC/Fe(VI)/H₂O₂ system exhibited excellent COD removal performance with a removal rate of 57% under slightly neutral conditions in laboratory experiments. In addition, the effluent COD was stabilized below 40 mg·L⁻¹ for 65 days at the pilot scale. Fe(IV) and ¹O₂ were confirmed to be the main active species in the degradation process through electron paramagnetic resonance (EPR) and quenching experiments. C=O, O-C=O, N sites and Fe⁰ were responsible for the generation of Fe(IV) and ¹O₂ in the FSC/Fe(VI)/H₂O₂ system. Furthermore, the cost per ton of water treated by the pilot-scale FSC/Fe(VI)/H₂O₂ system was calculated to be only 0.6209 USD/t, further confirming the application potential of the FSC/Fe(VI)/H₂O₂ system. This study promotes the engineering application of heterogeneous Fenton-like systems for water treatment. Full article

The extensive use of herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA), coupled with its limited biodegradability, has led to its ubiquitous presence in aquatic environments. This work investigates the removal of MCPA (100 mg/L) in the aqueous phase via solar photo-Fenton. The process was carried out in a 700 mL reactor using a Xe lamp that simulates solar radiation (λ: 250–700 nm). A parametric study was conducted to assess the influence of dissolved O₂ on the reaction medium, Fe²⁺ dosage, H₂O₂ concentration and pH₀. The results indicate that dissolved O₂ boosts pollutant mineralization, even working at sub-stoichiometric H₂O₂ concentrations. Under optimal reaction conditions ([Fe²⁺]: 7.5 mg/L, [H₂O₂]₀: 322 mg/L (stoichiometric dose), pH₀: 3.5), the MCPA reached almost complete mineralization (X_TOC: 98.40%) in 180 min. Phytotoxicity and ecotoxicity assessments of treated effluents revealed that even working at sub-stoichiometric H₂O₂ dosages, toxicity decreases with the solar photo-Fenton treatment. Finally, the solar photo-Fenton process was evaluated in relevant matrices (river water and WWTP secondary effluent) and a realistic pollutant concentration (100 µg/L). In all cases, the pollutant degradation was ≥70% in 60 min, demonstrating the potential of this technology as a tertiary treatment. Full article

The conventional Fenton process generates large amounts of Fenton sludge during wastewater treatment. Achieving effective utilization of Fenton sludge and reducing its production remain pivotal challenges. In this study, Fenton sludge biochar catalysts (Cat) were prepared using Fenton sludge via pyrolysis. In addition, chemical oxygen demand (COD) from secondary effluent was removed by Fenton sludge biochar catalysts activated with H₂O₂/Fe(VI). Specifically, the removal efficiency of COD could reach 46.2% in the Cat−2/H₂O₂/Fe(VI) system under weakly alkaline conditions. The mechanistic analysis confirmed that high-valent iron, ^•OH, O₂^•−, and ¹O₂ all participate in the degradation process. Furthermore, a continuous-flow reactor was applied to treat secondary effluent, with COD decreasing from 65 mg/L to 36 mg/L. This study provides new insights into the resource utilization of Fenton sludge and the treatment of complex wastewater. Full article

An aqueous mixture of three compounds (atrazine, carbamazepine, and p-chlorobenzoic acid) has been treated by photochemical processes including photolysis and photocatalysis with 10.7% TiO₂ supported on ceramic foams of mullite. Experiments were conducted in both ultrapure water and in a secondary effluent from a municipal wastewater treatment plant. Radiation at 365 nm was totally inefficient in the photolytic process carried out in ultrapure water; however, some sensitization phenomena were observed when municipal wastewater was used as a bulk matrix. In the latter case, conversion values in the range of 20–30% were obtained after 2 h. The photocatalytic process was much more effective experiencing conversions above 80% after just 80 min of reaction. The nature of the matrix used exerted a significant influence. Use of municipal wastewater slowed down the process due to the scavenging character of the natural organic matter content. Test runs in the presence of carbonates and t-butyl alcohol suggested that radical carbonates play some role in contaminant abatement, and secondary radicals generated after the t-BuOH attack by HO^● radicals should also be considered in the reaction mechanism. A pseudo-empirical mechanism of reactions sustains the experimental result obtained, acceptably modeling the effects of a water matrix, scavenger addition, and radiation volumetric photon flux. Full article

Pharmaceutical residues are emerging contaminants of growing concern due to their persistence and poor removal efficiency in conventional wastewater treatment plants. This study evaluates UVC photolysis with type C ultraviolet radiation (UVC) and UVC/TiO₂ photocatalysis of a mixture of four pharmaceuticals—atenolol (ATL), acetaminophen (ACM), clofibric acid (CLA), and antipyrine (ANT)—commonly found in treated urban wastewater. A comprehensive kinetic model was developed to describe their degradation, taking into account the generation of reactive oxygen species (ROS): hydroxyl (HO^●), superoxide ion (O₂^●−) radicals, and singlet oxygen (¹O₂), along with their reactions with both the pharmaceuticals and dissolved organic matter. Direct quantum yields were determined as 8.05 × 10⁻³ mol·Einstein⁻¹ for ATL, 1.93 × 10⁻³ for ACM, 3.12 × 10⁻¹ for CLA, and 5.12 × 10⁻² for ANT. In addition, rate constants of the reactions between singlet oxygen and pharmaceuticals were 9.93, 1.3 × 10⁶, 1.18 × 10², and 1.14 × 10⁴ M⁻¹s⁻¹ for ATL, ACM, CLA, and ANT, respectively. Scavenger experiments confirmed the key role of the ROS involved. The model reproduces the inhibitory effect of natural organic matter in secondary effluent and, in most cases, treated, accurately predicts the concentration profiles of the pharmaceuticals. Under photocatalytic conditions (0.10 g·L⁻¹ TiO₂), all compounds were completely degraded in less than 15 min. This validated model provides a useful tool for understanding the degradation mechanisms of pharmaceutical mixtures and for supporting the design of effective water strategies based on photochemical processes. Full article

Flow virometry (FVM) offers a promising approach for monitoring viruses and virus-like particles (VLPs) in environmental samples. This study compares levels of non-specific VLPs across a wastewater treatment plant (WWTP) with levels of somatic coliphage, (F+) specific coliphage, Pepper Mild Mottle Virus (PMMoV), CrAssphage (CrAss), and Tomato Brown Rugose Fruit Virus (ToBRFV). All targets were quantified in influent, secondary-treated effluent, and tertiary-treated effluent at the University of California, Davis Wastewater Treatment Plant (UCDWWTP) over 11 weeks. We established an FVM-gating boundary for VLPs using bacteriophages T4 and ϕ6 as well as four phages isolated from wastewater. We then utilize T4 alongside three submicron beads as quality controls in the FVM assay. Coliphage was measured by standard plaque assays, and genome copies of PMMoV, CrAss, and ToBRFV were measured by digital droplet (dd)PCR. FVM results for wastewater revealed distinct microbial profiles at each treatment stage. However, correlations between VLPs and targeted viruses were poor. Trends for virus inactivation and removal, observed for targeted viruses during wastewater treatment, were consistent with expectations. Conversely, VLP counts were elevated in the WWTP effluent relative to the influent. Additional sampling revealed a decrease in VLP counts during the filtration treatment step following secondary treatment but a substantial increase in VLPs following ultraviolet disinfection. Defining application boundaries remain crucial to ensuring meaningful data interpretation as flow cytometry and virometry take on greater significance in water quality monitoring. Full article

The risk of human exposure to micro- and nanoplastics (MNPs) has received increasing attention in recent years. Consumption of drinking water is a significant route of exposure to MNPs. While previous studies focus on MNPs in treated wastewater or final effluent, research addressing drinking water networks (DWNs) as potential secondary sources of MNPs remains sparse. However, how DWN, a critical component transporting water from treatment plants to consumers, contributes to secondary contamination remains underexplored in existing studies. We extracted keywords from reviewed literature using bibliometric methods and conducted correlation analyses, revealing four research clusters: baseline detection, health assessments, nanoplastic, and treatment. The abundance of MNPs in DWN ranged from 0.01 to 1.4 items/L. The abundance varied between 679.5 and 4.5 × 10⁷ items/kg when calculated based on sample mass (in scales or debris). Based on the shape and polymer composition of MNPs, the DWN is strongly suspected to contribute to the secondary contamination of MNPs in tap water. We also reviewed the main mechanisms for the formation and release of MNPs in pipelines, including mechanical forces, water hammer effects, and chemical aging. Our review highlighted the current gaps in the research on potential MNP contamination in the DWN. It will contribute to understanding the contribution of the DWN to MNP contamination and provide a framework for future monitoring and research efforts. Full article

Wastewater treatment plants (WWTPs) play a crucial role in treating sewage, which undergoes multiple treatment stages to ensure a safe treated effluent. However, any interference during these stages can compromise the final effluent quality. Such is the case of the overgrowth of the microcrustacean Daphnia spp., known to inhabit WWTPs, but with its presence in the decantation stage negatively impacting effluent clarification and further disinfection. This study aimed to evaluate how the effluent quality parameters influence the occurrence of Daphnia spp. in the secondary decanter of a WWTP. Wastewater monitoring data collected from 2017 to 2022 were analyzed. Firstly, as the COVID-19 pandemic occurred during the studied period, it was assessed whether the quality and load of the raw wastewater changed. Subsequently, an analysis was carried out using multivariate statistical methods for all the steps of WWTP. Comparing the periods before and during the pandemic, the raw wastewater volume decreased by 19.58%, and the BOD, COD, and TSS decreased by 37.78%, 16.86%, and 35.75%, respectively. These were the parameters affected the most. The statistical analysis revealed correlations between the presence of Daphnia spp. and specific effluent quality parameters, including raw wastewater BOD values below 500 mg L⁻¹, treated effluent BOD values below 13 mg L⁻¹, and pH levels exceeding 7.3. Additionally, BOD and pH were highlighted as critical parameters influencing their presence or absence. Full article

The presence of pharmaceuticals in wastewater raises concerns about the toxicological risks associated with its discharge and reuse. During the COVID-19 pandemic, widespread use of antivirals (ATVs), along with plastic gloves and masks, further contributed to pharmaceuticals in wastewater. Chlorination, commonly used for wastewater disinfection, may alter the toxicity of antivirals in the presence of microplastics (MPs) and complex organics in secondarily treated wastewater. To investigate this, synthetic secondary effluent containing Favipiravir (FAV) and Oseltamivir (OSE) was exposed to various chlorination conditions, both with and without MPs. The changes in the concentrations of FAV and OSE were measured using LC-MS/MS with isotopically labeled standards. Chlorination was more effective in removing Favipiravir (42 ± 4%) than Oseltamivir (26 ± 3%). The ecotoxicological effects were assessed on two species—Aliivibrio fischeri (a bacterium) and Enchytraeus crypticus (a soil invertebrate)—to evaluate potential impacts on aquatic and soil environments, though discharge of or irrigation with treated wastewater, respectively. Results indicated that chlorination of wastewater itself increased toxicity more significantly than the chlorination of antivirals to either species, suggesting that chlorination may not be as beneficial despite its cost-effectiveness. The effects of MPs in chlorinated wastewater on toxicity highlighted the importance of sample matrices in environmental toxicity studies. Full article

Not having the same grade of popularity as other metals like rare earth elements, gold, copper, etc., strontium is a chemical element with wide uses in daily life, which is why it appears in the EU 2023 list of Critical Raw Materials. Among the sources (with celestine serving as the raw material) used to recover the element, the recycling of some Sr-bearing secondary wastes is under consideration, and it is also worth mentioning the interest in the removal of strontium from radioactive effluents. To reach these goals, several technological alternatives are being proposed, with the most widely used being the adsorption of strontium or one of its isotopes on solid materials. The present work reviews the most recent advances (for 2024) in the utilization of diverse technologies, including leaching, adsorption, liquid–liquid extraction, etc., in the recovery/elimination of Sr(II) and common ⁹⁰Sr and ⁸⁵Sr radionuclides present in different solid or liquid wastes. While adsorption and membrane technologies are useful for treating Sr-diluted solutions (in the mg/L order), liquid–liquid extraction is more suitable for the treatment of Sr-concentrated solutions (in the g/L order). Full article

Furazolidone, a nitrofuran antibiotic, has been broadly used in aquaculture and veterinary medicine, and its presence in water poses considerable environmental and health hazards due to its toxicity. This study investigated a hybrid photocatalytic process for the removal of furazolidone, employing graphitic carbon nitride (g-C₃N₄) and persulfate anions (PS) under both laboratory and pilot-scale conditions. The synergistic effect of g-C₃N₄ and PS enhanced the generation of reactive species, facilitating the efficient degradation of FZ in two different aqueous matrices. Through scavenging studies, positive holes were determined to be the dominant reactive species, followed by sulfate radicals. Seven transformation products of FZ were tentatively identified via UHPLC-LTQ/Orbitrap MS analysis. The optimized photocatalytic system (g-C₃N₄/PS) achieved a 100% removal of furazolidone in less than 60 min under simulated solar light, demonstrating its potential for large-scale application in wastewater remediation. Furthermore, pilot-scale experiments using real secondary treated municipal wastewater proved that the applied process is capable of achieving an 86.2% removal of furazolidone (k = 0.017 min⁻¹) as well as a 90% decrease in effluent ecotoxicity within 120 min of UV_A irradiation. This study provides insights into sustainable processes for the removal of antibiotic contaminants from wastewater and underscores the role of g-C₃N₄-based photocatalytic approaches in upper-scale applications. Full article

The growing and unprecedented water crisis leads to the need to find alternative water resources, and the reuse of treated urban wastewater is an excellent approach. Accordingly, in this work, the disinfection of a secondary effluent (W) discharged from a wastewater treatment plant (WWTP) by hydrogen peroxide combined with radiation (H₂O₂+UV/visible) was studied with the aim of obtaining treated water that can be reused. Firstly, the effect of hydrogen peroxide alone, radiation per se and the combined H₂O₂+UV/Visible process in the inactivation of enterobacteria were assessed. It was found that the oxidant alone is not efficient; the maximum inactivation is achieved when the oxidant and radiation are used simultaneously. For the first time, the effect of some operational parameters, namely the hydrogen peroxide concentration (between 50 and 125 mg/L), initial pH (from 5.0 to 7.0), temperature (between 15 and 25 °C), and radiation intensity (100 to 500 W/m²), on the efficiency of the disinfection process was assessed. When the process was carried out under the best operating conditions found ([H₂O₂] = 75 mg/L, pH = 5.0, T = 25 °C, and UV/visible light with I = 500 W/m²), total enterobacteria and total heterotrophs were inactivated and the abundance of the 16S rRNA, bla_TEM, qnrS, and intl1 genes was reduced. The cultivable microorganisms grew again after 3 days of storing the treated wastewater (TW), making it impossible to reuse such effluent after storage. Therefore, the potential capacity of a diverse bacterial community present in river water to inhibit the regrowth of potentially harmful bacteria present in the urban secondary wastewater after the application of the treatment process was also evaluated. To the authors’ knowledge, this has never been studied before. For this purpose, the TW was diluted with river water (R) at a volumetric percentage of 50/50—sample R+TW. It was found that, after storage, only the total heterotrophs grew, while the abundance of the targeted genes remained practically constant. The R+TW sample after storage met the legal limits for reuse in urban and agricultural applications. The results of this study suggest that the combination of the H₂O₂+UV/visible radiation treatment with dilution of the final treated effluent with natural surface water can contribute to reducing the burden of water scarcity. Full article

The management of forest species in the recovery of degraded areas of semi-arid regions is mainly limited by the availability of water and nutrients. Thus, the objective of this research was to evaluate the growth, yield, and energy characteristics of the wood of two forest species of the Brazilian semi-arid region subjected to deficient irrigation with sewage effluent by drip in degraded soil. For this, a field experiment was conducted in an agroforestry system with two native species of the Caatinga biome: sabiá (Mimosa caesalpiniifolia Benth) and aroeira (Myracrodruon urundeuva Allemão), intercropped with forage palm (Opuntia stricta (Haw) Haw). The wastewater used was domestic, coming from kitchen and bathroom sinks, which underwent primary and secondary treatment. The irrigation treatments were applied in the first two years: in the first year, water supply in the volume of 0.5 L/plant/week (WS_0.5), treated effluent in the volume of 0.5 L/plant/week (TE_0.5), and treated effluent in the volume of 1 L/plant/week (TE₁). In the second year, all treatments were leveled at 0.5 L/plant/week, and in the following two years, all irrigation treatments were discontinued. Growth variables were monitored and, at the end of the study period, wood production was calculated and energetic analyses were performed. The Richards model adjusted satisfactorily to the growth variables for the species studied. The treated effluent at a volume of 1 L/week increased the yield in condensed liquid and decreased the volatile materials (VM) of sabiá, while in aroeira it increased the basic density and VM, with a decrease in the gravimetric yield. Full article

Urban areas face challenges with water scarcity, and the use of non-conventional water resources for uses not requiring potable quality is being promoted more and more by governments and international agencies. However, non-conventional water resources, such as rainwater and greywater, need to be treated before use to avoid health risks and possible nuisance (smell, bacteria and algae proliferation in storage tanks, etc.). This study is aimed at demonstrating the feasibility of a system reusing treated greywater for toilet flushing, relying on a nature-based treatment technology—ground-based green façades—with limited maintenance requirements which is therefore easily replicable for decentralized treatment systems, like those of greywater reuse at building scales. The demonstrative system has been installed at the University of Jordan’s Al-Zahra dormitory in Amman and uses a degreaser as the primary treatment followed by ground-based green façade technology as a secondary treatment mechanism. The effluent is stored in an underground tank and directed to a tertiary treatment mechanism with UV lamps to remove pathogens before being reused for lawn irrigation and toilet flushing. Samples from influent and effluent were analyzed for various physical, chemical, and microbiological characteristics. The degreaser significantly reduced turbidity, TSS, total BOD₅, and total COD levels in greywater. When combined with the green wall façades, the system demonstrated high removal efficiencies, particularly for turbidity, TSS, total COD, and total BOD₅. The treated effluent met irrigation reuse standards for all the parameters, including total coliform and E. coli concentrations. The UV disinfection unit proved to be an effective post-treatment step, ensuring that water quality standards for reuse were met. The system’s overall performance highlights its ability to manage low- to medium-strength greywater. Results suggest the applied green wall system has significant potential for wider adoption in urban settings. Full article