Alerta epidemiológica: detección de poliovirus (cVDPV3) en aguas residuales, consideraciones para la Región de las Américas - 14 de octubre del 2024

Tras la confirmación de poliovirus circulante derivado de la vacuna tipo 3 (cVDPV3) detectado en muestras de aguas residuales recolectadas en Guayana Francesa, la Organización Panamericana de la Salud/Organización Mundial de la Salud (OPS/OMS) reitera a los Estados Miembros la importancia de alcanzar y mantener una cobertura de vacunación contra la polio superior al 95% en cada distrito o municipio para minimizar el riesgo de un brote. Adicionalmente, la OPS/OMS enfatiza la necesidad de fortalecer la vigilancia epidemiológica de la parálisis flácida aguda (PFA) y actualizar los planes nacionales de preparación y respuesta ante brotes de poliovirus. Estas medidas aseguran una detección y respuesta oportunas y eficientes ante la importación del poliovirus salvaje o del poliovirus derivado de la vacuna (VDPV), o la emergencia del VDPV en cualquier país de la Región.

Metagenomic insights into plasmid-mediated antimicrobial resistance in poultry slaughterhouse wastewater: antibiotics occurrence and genetic markers.

Slaughterhouse wastewater represents important convergence and concentration points for antimicrobial residues, bacteria, and antibiotic resistance genes (ARG), which can promote antimicrobial resistance propagation in different environmental compartments. This study reports the assessment of the metaplasmidome-associated resistome in poultry slaughterhouse wastewater treated by biological processes, employing metagenomic sequencing. Antimicrobial residues from a wastewater treatment plant (WWTP) that treats poultry slaughterhouse influents and effluents were investigated through high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). Residues from the macrolide, sulfonamide, and fluoroquinolone classes were detected, the latter two persisting after the wastewater treatment. The genetic markers 16S rRNA rrs (bacterial community) and uidA (Escherichia coli) were investigated by RT-qPCR and the sul1 and int1 genes by qPCR. After treatment, the 16S rRNA rrs, uidA, sul1, and int1 markers exhibited reductions of 0.67, 1.07, 1.28, and 0.79 genes copies, respectively, with no statistical significance (p > 0.05). The plasmidome-focused metagenomics sequences (MiSeq platform (Illumina®)) revealed more than 100 ARG in the WWTP influent, which can potentially confer resistance to 14 pharmacological classes relevant in the human and veterinary clinical contexts, in which the qnr gene (resistance to fluoroquinolones) was the most prevalent. Only 7.8% of ARG were reduced after wastewater treatment, and the remaining 92.2% were associated with an increase in the prevalence of ARG linked to multidrug efflux pumps, substrate-specific for certain classes of antibiotics, or broad resistance to multiple medications. These data demonstrate that wastewater from poultry slaughterhouses plays a crucial role as an ARG reservoir and in the spread of AMR into the environment.

Pollution control and biodiesel production with microalgae: new perspectives on the use of flat panel photobioreactors regarding variation in volume application rate.

In the present study, the microalga Arthrospira platensis DHR 20 was cultivated in vertical flat-plate photobioreactors (FPBRs) to bioremediate anaerobically digested cattle wastewater (ACWW) and used as a growth substrate. The final objective was to evaluate the properties of the oil extracted from this biomass to determine its potential for biodiesel production. The process was divided into five phases, varying the volume of the applied substrate: 1 L (Phase I), 5 L (Phase II), 10 L (Phase III), 15 L (Phase IV), and 20 L (Phase V). Dry biomass reached a maximum of 5.7 g L-1, and productivity peaked at 0.74 g L-1d-1. The highest rate of CO2 biofixation was 1213.5 mg L-1 day-1, showing good potential for purifying the air. The highest specific maximum growth rate (µmax) and the shortest doubling time (Dt) were found during Phase I. The removal of pollutants and nutrients during the experimental phases ranged from 65.8% to 87.1% for chemical oxygen demand (COD), 82.2% to 85.8% for total organic carbon (TOC), 91% to 99% for phosphate (PO43-), 62.5% to 93% for nitrate (NO3-), 90.4% to 99.7% for ammoniacal nitrogen (NH4+), and 86.5% to 98.5% for total nitrogen (TN). The highest lipid production recorded was 0.172 g L-1 day-1. The average cetane number recorded in Phase IV of 51 suggests that the fuel will ignite efficiently and consistently, providing smooth operation and potentially reducing pollutant emissions. The analysis of fatty acids revealed that the produced biodiesel has the potential to be used as an additive for other low-explosive biocombustibles, representing an innovative and sustainable approach that simultaneously offers bioremediation and carbon sequestration.

Performance evaluation of a wastewater treatment plant from a dairy in the state of Minas Gerais, Brazil: a case study.

Wastewater generated in dairies has a strong polluting potential and must be treated for disposal into water bodies or reuse. The objective of this work was to analyze the efficiency of removing pollutants through the processes used by a wastewater treatment plant (WWTP) of a dairy located in the state of Minas Gerais, Brazil. For this purpose, the results of the characterization analyses referring to raw and treated wastewater were interpreted. The results showed that the sequence of processes used in the WWTP (water/oil separation, dissolved air flotation, followed by biodegradation in an upflow anaerobic filter) is efficient in removing on average 99.1% of COD and 98.7% of BOD5. For treated wastewater, data on pH and concentration of total suspended solids, total ammoniacal nitrogen, surfactants, settleable solids, and oils and greases also met the standards for disposal into water bodies. For reuse in agriculture, treated wastewater can be used for irrigation, but it is recommended to additionally evaluate the Escherichia coli parameter. When evaluating the existence of linear correlation between COD and BOD5 data, it was possible to find only a moderate correlation (R2 equal to 0.7) for treated wastewater.

Effects of LED lights and cytokinin on the phytotreatment of simulated swine wastewater by Azolla spp.: Pollutant removal and biomass valorization.

Phytoremediation is an eco-friendly and affordable option for tackling wastewater pollutants. The study focused on how light-emitting diodes (LED) light exposure, measured by intensity and duration (photoperiod), along with cytokinin, impacts Azolla microphylla's simulated swine wastewater treatment performance and biomass production. Under optimal treatment conditions, high removals of COD (89.2 % to 90.8 %), N-NH4+ (72.6 % to 91.2 %), N-NO3- (84.4 % to 88.6 %), Cu (75.4 % to 86.4 %), sulfamethoxazole (77.0 % to 79.0 %), P-PO43- (54.1 % to 59.9 %) and DOC (67.4 % to 71.3 %) while Zn presented a more moderate reduction (2.0 % to 9.7 %). Biomass productivity reached up to 34.8 t ha-1 yr-1. Protein production accounted for 23 % to 27 % of dry weight, while lipids ranged from 20 % to 34 % of dry biomass. Carbohydrate content varied from 8 % to 28 % of fresh weight. Higher light intensities, with both high or low values of photoperiods, and low concentrations of cytokinin were identified as optimal conditions for removal of almost all pollutants. However, pollutant removal was impacted differently by LED light and cytokinin concentration. In treatment conditions with the shortest photoperiods (8 h), the lowest residual Cu and Zn concentrations, whereas with longer photoperiods (24 h), the lowest residual concentrations of N-NH4+ and P-PO43- concentrations were recorded. On the other hand, SMX was the only parameter in which cytokinin had a clear influence on its removal, with the lowest residual concentration observed under 8-hour photoperiods combined with the lowest tested cytokinin concentrations (0.3 mg L-1). For residual COD and N-NO3-, no discernible pattern was evident for any of the analyzed factors. Therefore, the study demonstrates the potential for treating simulated swine wastewater using Azolla microphylla, aligned with its ability to produce biomass rich in high-value compounds.

Development and comparative assessment of RT-qPCR and duplex RT-LAMP assays for the monitoring of Aichi virus A (AiV-A) in untreated wastewater samples.

Diverse enteric pathogens, transmitted through human and animal feces, can cause gastroenteritis. Enteric viruses, such as human Aichi virus, specifically genotype A (AiV-A), are emerging pathogens that cause illnesses even at low doses and are spreading globally. This research developed a reverse transcription quantitative polymerase chain reaction (RT-qPCR) assay targeting the 3CD junction and a reverse transcription colorimetric loop-mediated isothermal amplification (RT-cLAMP) duplex assay targeting junctions 2BC and 3CD of the AiV-A genome for rapid and sensitive detection of this virus in metropolitan and regional wastewater samples in Queensland, Australia. The performance of these assays was evaluated using control materials and by analyzing wastewater samples. In serially diluted control materials, RT-qPCR provided quantifiable data (mean 1.51 log10 GC/2 µL of nucleic acid) down to a dilution of 1 × 10-5 pg/µL. In comparison, the duplex RT-cLAMP assay detected down to 1 × 10-4 pg/µL, indicating that its sensitivity was one order of magnitude less than that of RT-qPCR. Of the 38 wastewater samples from 38 metropolitan and regional wastewater treatment plants (WWTPs) in Queensland, Australia, 21 (55.3 %) tested positive by RT-qPCR with concentrations ranging from 3.60 to 6.23 log10 GC/L. In contrast, only 15 (39.5 %) of 38 wastewater samples were positive using the duplex RT-cLAMP assay. The methods demonstrated substantial qualitative agreement (κ = 0.730), with a concordance of 86.5 %, demonstrating the reliability of RT-cLAMP for detecting AiV-A in wastewater samples. The duplex RT-cLAMP assay, despite demonstrating reduced detection sensitivity, has proven effective and holds promise as a supplementary approach, especially in settings with limited resources where rapid and affordable testing is crucial.

Optimization of indirect wastewater characterization using led spectrophotometry: a comparative analysis of regression, scaling, and dimensionality reduction methods.

LED spectrophotometry is a robust technique for the indirect characterization of wastewater pollutant load through correlation modeling. To tackle this issue, a dataset with 1300 samples was collected, from both raw and treated wastewater from 45 wastewater treatment plants in Spain and Chile collected over 4 years. The type of regressor, scaling, and dimensionality reduction technique and nature of the data play crucial roles in the performance of the processing pipeline. Eighty-four pipelines were tested through exhaustive experimentation resulting from the combination of 7 regression techniques, 3 scaling methods, and 4 possible dimensional reductions. Those combinations were tested on the prediction of chemical oxygen demand (COD) and total suspended solids (TSS). Each pipeline underwent a tenfold cross-validation on 15 sub-datasets derived from the original dataset, accounting for variations in plants and wastewater types. The results point to the normalization of the data followed by a conversion through the PCA to finally apply a Random Forest Regressor as the combination which stood out These results highlight the importance of modeling strategies in wastewater management using techniques such as LED spectrophotometry.

Obtaining more contaminant-resistant variants from a native Chlorella vulgaris strain.

Cildáñez stream (in Matanza-Riachuelo basin, Buenos Aires) is one of the most polluted watercourses of Argentina, containing a mixed contamination from agricultural and industrial wastes. The application of water bioremediation processes for this kind of effluent will require microorganisms with a high tolerance to contamination. In this sense, obtaining higher contaminant-resistant microalgae lines is widely desired. In this study, adaptive laboratory evolution (ALE) and random mutagenesis were used to obtain Chlorella vulgaris LMPA-40 strains adapted to grow in polluted water from the Cildáñez stream. The ALE process was performed by 22 successive subcultures under selective pressure (Cildáñez wastewater alone or with the addition of phenol or H2O2) while random mutagenesis was performed with UV-C radiation at 275nm. Not all the cell lines obtained after ALE could adapt enough to overcome the stress caused by the Cildáñez wastewater, indicating that the process is quite random and depends on the stressor used. The best results were obtained for the Cildáñez wastewater adapted cells (Cild 3 strain) that were more resistant than the original strain. The concentration of protein, Chlorophyll A, Chlorophyll B, and carotenoids in the Cild 3 ALE evolved strain was higher than that of the control strain. However, this strain exhibited half of the lipid content compared to the same control strain. Interestingly, these alterations and the acquired tolerance may be reversed over time during storage. These findings suggest that the acquisition of novel cell lines could not be permanent, a fact that must be considered for future trials.

Detection of SARS-CoV-2 variants in hospital wastewater in Peru, 2022. / Detección de variantes del SARS-CoV-2 en aguas residuales de hospitales en Perú, 2022.

OBJECTIVE.: To identify the presence of the SARS-CoV-2 virus in wastewater from hospitals in Peru. MATERIALS AND METHODS.: Water samples were collected from the effluents of nine hospitals in Peru during March and September 2022. SARS-CoV-2 was identified by using Illumina sequencing. Variant, lineage and clade assignments were carried out using the Illumina and Nextclado tools. We verified whether the SARS-CoV-2 variants obtained from wastewater were similar to those reported by the National Institute of Health of Peru from patients during the same period and region. RESULTS.: Eighteen of the 20 hospital wastewater samples (90%) provided sequences of sufficient quality to be classified as the Omicron variant according to the WHO classification. Among them, six (30%) were assigned by Nextclade to clades 21K lineage BA.1.1 (n=1), 21L lineage BA.2 (n=2), and 22B lineages BA.5.1 (n=2) and BA .5.5 (n=1). CONCLUSIONS.: SARS-CoV-2 variants were found in hospital wastewater samples and were similar to those reported by the surveillance system in patients during the same weeks and geographic areas. Wastewater monitoring could provide information on the environmental and temporal variation of viruses such as SARS-CoV-2.Motivation for the study. To contribute to the surveillance of environmental samples from hospital effluents in order to achieve early warning of possible infectious disease outbreaks. Main findings. The Omicron variant of the COVID-19 virus was detected in wastewater from hospitals in Puno, Cuzco and Cajamarca; these results are similar to the reports by the Peruvian National Institute of Health based on nasopharyngeal swab samples. Implications. The presence of the Omicron variant in hospital wastewater during the third wave of the pandemic should raise awareness of the treatment system before wastewater is discharged into the public sewer system.

Metaviromic reveals the dynamics and diversity of the virosphere in wastewater samples from Natal, Brazil.

The COVID-19 pandemic underscored the significance of omics technology and Wastewater-Based Epidemiology for epidemic preparedness. This study investigates the virosphere in wastewater samples from Natal (Brazil), aiming to understand its structure, relationships, and potential. Metaviromic analysis was used on DNA and RNA from weekly samples collected over a year (June/2021 to May/2022) from three wastewater treatment plants. The virosphere showed stability, particularly in viruses infecting microorganisms and plants. However, an alternation of representatives of viruses that infect animals has been observed. Among the most abundant viruses infecting microorganisms are genera associated with the bacterial genera Escherichia, Pseudomonas, and Caulobacte. Regarding the viruses infecting plants, Sobemovirus and Tobamovirus are the most abundant genera. Odontoglossum ringspot virus was identified as a possible RNA virus biomarker. Among DNA viruses infecting animals, genera Bocaparvovirus and Mastadenovirus are the most prevalent. Intriguingly, some Poxviridae family members were observed in the samples. Co-occurrence network analysis identified potential biomarkers like Volepox virus, Anatid herpesvirus 1, and Caviid herpesvirus 2. Among RNA viruses affecting animals, Mamastrovirus, Rotavirus, and Norovirus genera were the most abundant pathogens. Furthermore, members of the Coronaviridae family exhibited a high degree of centrality values in the co-occurrence network, even connecting with unclassified viruses. The study emphasizes the importance of research in understanding the roles of unclassified viruses. In addition, we observed an association between Coronaviridae reads, rainfall, and the number of reported COVID-19 cases. Our study highlights the diversity and complexity of the viral community in wastewater and the need for research to understand better the ecological roles unclassified viruses play. Such advances will significantly contribute to our preparedness and response to future viral threats. Furthermore, our study contributes to knowledge of virosphere dynamics, offering insights that can contribute to the direction of future public health policies and interventions.

Eco-friendly concrete: Combining treated wastewater and recycled aggregates.

The concrete industry is a significant consumer of drinking water and natural aggregates, such as sand and gravel. However, the scarcity of water and aggregate resources and the challenges associated with the disposal of construction and demolition waste prompted the exploration of alternative materials. This study investigates the feasibility of incorporating secondary treated wastewater from UASB reactors followed by trickling filters and mixed recycled aggregates as potential alternatives. To assess the viability of these alternatives, the study considered the replacement of 100% potable water with treated wastewater, as well as varying proportions of recycled gravel (20, 40, 60, 80, and 100%) and recycled sand (10, 20, 30, 40, and 100%). Physical and mechanical properties were negatively affected, but it was possible to reach compressive results over 40 MPa and splitting tensile strength over 4 MPa for almost all mixes. Regarding physical properties, the use of alternative materials caused poorer outcomes for density, water absorption, and air-void ratio. The limited magnitude of these detrimental effects indicates the potential of manufacturing concrete with the addition of combined treated wastewater and recycled aggregate as a viable strategy while enhancing reuse practices.

Performance of vertical and horizontal treatment wetlands planted with ornamental plants in Central Chile: comparative analysis of initial operation stage for effluent reuse in agriculture.

This study comparatively evaluated effluent reuse from two TWs-a horizontal subsurface flow (HF) and a vertical subsurface flow (VF)-used for rural wastewater treatment in Central Chile during the initial operation stage. The two TWs were planted with Zantedeschia aethiopica and were operated for 10 months at a pilot scale. The water quality of the influent and effluents was measured and compared with reuse regulations. The results showed similarities in the behavior of the effluents from the two TWs, presenting differences only in the chemical oxygen demand (COD) and different forms of nitrogen, suggesting the necessity of complementary treatment stages or modifications to the operation. The effluents from the HF better fulfilled the reuse standards for irrigation, as the VF faced problems associated with its size. However, a complementary disinfection system is necessary to improve pathogen removal in the effluents coming from the two TWs, especially to be reused as irrigation water for crops. Finally, this work showed the potential for applying subsurface TWs for wastewater treatment in rural areas and reusing their effluents as irrigation water, practice that can contribute to reducing the pressure on water resources in Chile, and that can be used as an example for other countries facing similar problems.

Structural and functional bacterial biodiversity in a copper, zinc and nickel amended bioreactor: shotgun metagenomic study.

BACKGROUND: At lower concentrations copper (Cu), zinc (Zn) and nickel (Ni) are trace metals essential for some bacterial enzymes. At higher concentrations they might alter and inhibit microbial functioning in a bioreactor treating wastewater. We investigated the effect of incremental concentrations of Cu, Zn and Ni on the bacterial community structure and their metabolic functions by shotgun metagenomics. Metal concentrations reported in previous studies to inhibit bacterial metabolism were investigated. RESULTS: At 31.5 µM Cu, 112.4 µM Ni and 122.3 µM Zn, the most abundant bacteria were Achromobacter and Agrobacterium. When the metal concentration increased 2 or fivefold their abundance decreased and members of Delftia, Stenotrophomonas and Sphingomonas dominated. Although the heterotrophic metabolic functions based on the gene profile was not affected when the metal concentration increased, changes in the sulfur biogeochemical cycle were detected. Despite the large variations in the bacterial community structure when concentrations of Cu, Zn and Ni increased in the bioreactor, functional changes in carbon metabolism were small. CONCLUSIONS: Community richness and diversity replacement indexes decreased significantly with increased metal concentration. Delftia antagonized Pseudomonas and members of Xanthomonadaceae. The relative abundance of most bacterial genes remained unchanged despite a five-fold increase in the metal concentration, but that of some EPS genes required for exopolysaccharide synthesis, and those related to the reduction of nitrite to nitrous oxide decreased which may alter the bioreactor functioning.

Efficient PAHs removal and CO2 fixation by marine microalgae in wastewater using an airlift photobioreactor for biofuel production.

Microalgae cultures have emerged as a promising strategy in diverse areas, ranging from wastewater treatment to biofuel production, thus contributing to the search for carbon neutrality. These photosynthetic organisms can utilize the resources present in wastewater and fix atmospheric CO2 to produce biomass with high energy potential. In this study, the removal efficiency of Polycyclic Aromatic Hydrocarbons (PAHs), CO2 fixation and lipid content in the biomass produced from microalgae grown in airlift photobioreactor were evaluated. Four mesoscale cultures were carried out: Control (Seawater + Conway medium), Treatment A (Oil Produced Water + Poultry Effluent Water), Treatment B (Poultry Effluent Water + Seawater) and Treatment C (Oil Produced Water, Seawater and nutrients). The impact of biostimulation, through the addition of nutrients, on PAHs removal efficiency (up to 90%), CO2 fixation rate (up to 0.20 g L-1 d-1) and the composition of the generated biomass was observed. Primarily, the addition of nitrates to the culture medium impacted CO2 fixation rate of the microalgae. In addition, a direct correlation was observed between PAHs removal and lipid accumulation in the biomass, up to 36% in dry weight, demonstrating microalgae's ability to take advantage of the organic carbon (PAHs) present in the culture medium to generate lipid-rich biomass. The concentration of polysaccharides in the biomass obtained did not exceed 12% on a dry weight basis, and the Higher Heating Value (HHV) ranged between 17 and 21 MJ kg-1. Finally, the potential of generating hydrogen through pyrolysis was highlighted, taking advantage of the characteristics of biomass as a conversion route to produce biofuels. These results show that microalgae are effective in wastewater treatment and have great potential in producing biofuels, thus contributing to the transition towards more sustainable energy sources and climate change mitigation.

Citrobacter spp. and Enterobacter spp. as reservoirs of carbapenemase blaNDM and blaKPC resistance genes in hospital wastewater.

Antibiotic resistance has emerged as a global threat to public health, generating a growing interest in investigating the presence of antibiotic-resistant bacteria in environments influenced by anthropogenic activities. Wastewater treatment plants in hospital serve as significant reservoirs of antimicrobial-resistant bacteria, where a favorable environment is established, promoting the proliferation and transfer of resistance genes among different bacterial species. In our study, we isolated a total of 243 strains from 5 hospital wastewater sites in Mexico, belonging to 21 distinct Gram-negative bacterial species. The presence of ß-lactamase was detected in 46.9% (114/243) of the isolates, which belonging to the Enterobacteriaceae family. We identified a total of 169 ß-lactamase genes; blaTEM in 33.1%, blaCTX-M in 25.4%, blaKPC in 25.4%, blaNDM 8.8%, blaSHV in 5.3%, and blaOXA-48 in 1.1% distributed in 12 different bacteria species. Among the 114 of the isolates, 50.8% were found to harbor at least one carbapenemase and were discharged into the environment. The carbapenemase blaKPC was found in six Citrobacter spp. and E. coli, while blaNDM was detected in two distinct Enterobacter spp. and E. coli. Notably, blaNDM-1 was identified in a 110 Kb IncFII conjugative plasmid in E. cloacae, E. xiangfangensis, and E. coli within the same hospital wastewater. In conclusion, hospital wastewater showed the presence of Enterobacteriaceae carrying a high frequency of carbapenemase blaKPC and blaNDM. We propose that hospital wastewater serves as reservoirs for resistance mechanism within bacterial communities and creates an optimal environment for the exchange of this resistance mechanism among different bacterial strains. IMPORTANCE: The significance of this study lies in its findings regarding the prevalence and diversity of antibiotic-resistant bacteria and genes identified in hospital wastewater in Mexico. The research underscores the urgent need for enhanced surveillance and prevention strategies to tackle the escalating challenge of antibiotic resistance, particularly evident through the elevated frequencies of carbapenemase genes such as blaKPC and blaNDM within the Enterobacteriaceae family. Moreover, the identification of these resistance genes on conjugative plasmids highlights the potential for widespread transmission via horizontal gene transfer. Understanding the mechanisms of antibiotic resistance in hospital wastewater is crucial for developing targeted interventions aimed at reducing transmission, thereby safeguarding public health and preserving the efficacy of antimicrobial therapies.

Cultivation of Chlorella vulgaris in wastewater: biodiesel potential and wastewater remediation.

The present investigation has evaluated the use of effluents from a secondary municipal wastewater treatment plant for biomass production and potential of the biomass for biodiesel production. Cultivations of Chlorella vulgaris using wastewater, wastewater with supplementation, and WC medium were carried out. Effect of wastewater collected in different months on biomass productivity (BP) and lipid composition was studied. Methods based on NMR and GC-MS techniques were applied for determining the composition of the lipids and their fatty acid profile including poly unsaturated fatty acids (PUFAs). Lipids extracted are comprised of both neutral (tri acyl glycerides, TAG; free fatty acids, FFA) and polar (glyco glycero/phospho) lipids. The TAG content of the extracted lipids was determined in the range of 22.5-41.3% w/w. The NMR and GC-MS compositional results of microalgal lipids of biomasses cultivated in wastewater without nutrient supplementation, collected in different months, showed potential for biodiesel production. The fatty acid profiles of neutral and polar lipids, which are mainly comprised of saturated and unsaturated long alkyl chain (C16-C22) fatty acids, are potential sources for the biodiesel and food industry. The concentration of nitrates (45-78 mg L-1) in wastewater without supplementation, collected in different months, was found to be optimum to enable cultivation of biomasses with reasonably good BP of 21.5-28.1 mg L-1 day-1. Similar results have been obtained in the present work as well as reported in the literature in the case of WC medium (nitrate, 69 mg L-1) with BP of 25.5-28.2 mg L-1 day-1, thus highlighted the significance of the presented work.

Effect of monocultures and polycultures of Typha latifolia and Heliconia psittacorum on the treatment of river waters contaminated with landfill leachate/domestic wastewater in partially saturated vertical constructed wetlands.

Partially Saturated Vertical Constructed Wetlands (PSV-CWs) are novel wastewater treatment systems that work through aerobic and anaerobic conditions that favor the removal of pollutants found in high concentrations, such as rivers contaminated with domestic wastewater and landfill leachate. The objective of the study was to evaluate the efficiency of PSV-CWs using monocultures and polycultures of Typha latifolia and Heliconia psittacorum to treat river waters contaminated with leachates from open dumps and domestic wastewater. Six experimental units of PSV-CWs were used; two were planted with Typha latifolia monoculture, two with Heliconia psittacorum monoculture and two with polycultures of both plants. The results indicated better organic matter and nitrogen removal efficiencies (p < 0.05) in systems with polycultures (TSS:95%, BOD5:83%, COD:89%, TN:82% and NH4+:99%). In general, the whole system showed high average removal efficiencies (TSS:93%, BOD5:79%, COD:85%, TN:79%, NH4+:98% and TP:85%). Regarding vegetation, both species developed better in units with monocultures, being Typha latifolia the one that reached a more remarkable development. However, both species showed high resistance to the contaminated environment. These results showed higher removals than those reported in the literature with conventional Free Flow Vertical Constructed Wetlands (FFV-CWs), so PSV-CWs could be a suitable option to treat this type of effluent.

The research addresses the contamination of water resources in developing countries by landfill leachate and domestic wastewater discharges. It proposes treatment through Partially Saturated Vertical Constructed Wetlands (PSV-CWs), which, despite the limited information available, have been shown to be effective in removing pollutants in effluents with high concentrations. In addition to evaluating PSV-CWs, the study examines the impact of different types of vegetation on pollutant removal efficiency, concluding that PSV-CWs are a promising and viable option for the treatment of these effluents.

Amazon tropical fishes of commercial interest show human-cell contamination but no SARS-CoV-2 in a real-life scenario.

BACKGROUND: Amazonas was one of the most impacted Brazilian states by the COVID-19 pandemic. Mortality rates were high, and the health systems collapsed. It is important to identify possible intermediate reservoirs to avoid animal-to-human contamination. Several tropical fish are of commercial interest and are sold in large open-air markets in the region, representing a large economic and dietary importance. OBJECTIVES: This study aimed to verify if fish species of commercial importance, aerosols, and fish wastewater in local open-air markets, at a major capital city in the western Brazilian Amazon, are contaminated by SARS-CoV-2. METHODS: 488 fish, 50 aerosol, and 45 wastewater samples were analyzed for the presence of SARS-CoV-2. The samples were subjected to extraction using the BIOGENE Viral DNA/RNA Extraction kit, and the molecular diagnosis was tested for SARS-CoV-2 using the Bio-Manguinhos SARS-CoV-2 (EDx) Molecular Kit. RESULTS: It was not possible to detect the virus (Ct≤40, for Gene E) in these samples, however, in 181 samples of fish it was possible to detect the human RP gene (Ct≤35, for the RP Gene), indicating human contact. There was a high number of COVID-19 diagnoses in all city districts in which the samples were collected, showing that SARS-CoV-2 was circulating. CONCLUSION: This study indicates that fish of local commercial importance do not carry SARS-CoV-2 viral particles, despite circulation of SARS-CoV-2, and are not an important source of animal-to-human contamination. Despite these results, the human RP gene was found detectable in fish, air, and fish wastewater, showing that such places may carry human pathogens.

Assessment of crAssphage as a biological variable for SARS-CoV-2 data normalization in wastewater surveillance.

AIMS: This study aimed to assess the use of cross-assembled phage (crAssphage) as an endogenous control employing a multivariate normalization analysis and its application as a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) data normalizer. METHODS AND RESULTS: A total of 188 twelve-hour composite raw sewage samples were obtained from eight wastewater treatment plants (WWTP) during a 1-year monitoring period. Employing the N1 and N2 target regions, SARS-CoV-2 RNA was detected in 94% (177) and 90% (170) of the samples, respectively, with a global median of 5 log10 genomic copies per liter (GC l-1). CrAssphage was detected in 100% of the samples, ranging from 8.29 to 10.43 log10 GC l-1, with a median of 9.46 ± 0.40 log10 GC l-1, presenting both spatial and temporal variabilities. CONCLUSIONS: Although SARS-CoV-2 data normalization employing crAssphage revealed a correlation with clinical cases occurring during the study period, crAssphage normalization by the flow per capita per day of each WWTP increased this correlation, corroborating the importance of normalizing wastewater surveillance data in disease trend monitoring.

Development of an artificial neural network (ANN) for the prediction of a pilot scale mobile wastewater treatment plant performance.

Productive activities such as pig farming are a fundamental part of the economy in Mexico. Unfortunately, because of this activity, large quantities of wastewater are generated that have a negative impact in the environment. This work shows an alternative for treating piggery wastewater based on advanced oxidation processes (Fenton and solar photo Fenton, SPF) that have been probed successfully in previous works. In the first stage, Fenton and SPF were carried out on a laboratory scale using a Taguchi L9-type experimental design. From the statistical analysis of this design, the operating parameters: pH, time, hydrogen peroxide concentration [H2O2], and iron ferrous concentration [Fe2+] that maximize the response variables: Chemical Oxygen Demand (COD), Total Organic Carbon (TOC), and color were chosen. From these, a cascade forward neural network was implemented to establish a correlation between data from the variables to the physicochemical parameters to be measure being that a great fit of the data was obtained having a correlation coefficient of 0.99 which permits to optimize the pollutant degradation and predict the removal efficiencies at pilot scale but with a projection to a future industrial scale. A relevant result, it was found that the optimal values for maximizing the removal of physicochemical parameters were pH = 3, time = 60 min, H2O2/COD = 1.5 mg L-1, and H2O2/Fe2+ = 2.5 mg L-1. With these conditions degradation percentages of 91.44%, 47.14%, and 97.89% for COD, TOC, and color were obtained from the Fenton process, while for SPF the degradation percentage increased moderately. From the ANN analysis, the possibility to establish an intelligent system that permits to predict multiple results from operational conditions has been achieved.