Assessment of the surface water quality and primary health risk in urban wastewater and its receiving river Kathajodi, Cuttack of eastern India.

Kathajodi, the principal southern distributary of the Mahanadi River, is the vital source of irrigation and domestic water use for densely populated Cuttack city which receives anthropogenic wastes abundantly. This study assesses the contamination level and primary health status of urban wastewater, and its receiving river Kathajodi based on the physicochemical quality indices employing inductively coupled plasma mass spectroscopy and aligning with guidelines from the United States Environmental Protection Agency (USEPA) and WHO. The high WQI, HPI, and HEI in the catchment area (KJ2, KJ3, and KJ4) indicate poor water quality due to the influx of domestic waste through the primary drainage system and effluents of healthcare units. A high BOD (4.33-19.66 mg L-1) in the catchment indicates high organic matter, animal waste, bacteriological contamination, and low DO, resulting in deterioration of water quality. CR values beyond limits (1.00E - 06 to 1.00E - 04) in three locations of catchment due to higher Cd, Pb, and As indicate significant carcinogenic risk, while high Mn, Cu, and Al content is responsible for several non-carcinogenic ailments and arsenic-induced physiological disorders. The elevated heavy metals Cd, Cu, Fe, Mn, Ni, and Zn, in Kathajodi, could be due to heavy coal combustion, vehicle exhaust, and industrial waste. On the other hand, Cu, Fe, K, and Al could be from agricultural practices, weathered rocks, and crustal materials. Positive significant (p ≤ 0.05) Pearson correlations between physicochemical parameters indicate their common anthropogenic origin and similar chemical characteristics. A strong correlation of PCA between elements and physiological parameters indicates their role in water quality deterioration. Assessing the surface water quality and heavy metal contents from this study will offer critical data to policymakers for monitoring and managing public health concerns.

Assessment of restriction measures implemented during COVID pandemics on community lifestyle choices via wastewater-based epidemiology.

SARS-CoV-2 pandemic affected lifestyle habits, and the mental health and wellbeing of people around the world. In this manuscript, two towns (Paulton and Radstock) and two cities (Bath and Bristol) in Southwest England (> 1 million people) were monitored for two years using Wastewater-Based Epidemiology to assess impacts of COVID (including management measures such as lockdowns and movement restrictions) on community lifestyle choices: illicit drugs, legal stimulants, abused pharmaceuticals and pain pharma usage. Results were triangulated with key dates captured during the pandemic (national lockdowns, restrictions and social distancing measures, etc.). This highlighted a reduction in cocaine intake (as benzoylecgonine) (community average: -36 %) during the first lockdown and an increase in illicit drugs usage after the 3rd national lockdown (community averages for amphetamine: +8 %, cocaine/benzoylecgonine: +39 %, ketamine:+70 %) when restrictions were removed, and social interaction and recreational activities increased. There was a reduction in the intake of caffeine (as 1,7-dimethylxanthine) (community average:-39 %) after 3rd national lockdown coinciding with pubs reopening while nicotine intake (via cotinine) remained stable indicating lack of impact of COVID on smoking habits. Pain pharma often used in pain management resulting from injuries linked with sport activities (naproxen and diclofenac) showed decrease in usage due to lockdown restrictions in physical exercise and access to gyms/sport facilities.

Human health risk assessment framework for new water resource recovery-based bio-composite materials.

A new type of bio-composite material is being produced from water-recovered resources such as cellulose fibres from wastewater, calcite from the drinking water softening process, and grass and reed from waterboard sites. These raw materials may be contaminated with pathogens and chemicals such as Escherichia coli, heavy metals, and resin compounds. A novel risk assessment framework is proposed here, addressing human health risks during the production of new bio-composite materials. The developed framework consists of a combination of existing risk assessment methods and is based on three main steps: hazard identification, qualitative risk mapping, and quantitative risk assessment. The HAZOP and Event Tree Analysis methodologies were used for hazard identification and risk mapping stages. Then, human health risks were quantitatively assessed using quantitative chemical risk assessment, evaluating cancer and non-cancer risk, and quantitative microbial risk assessment. The deterministic and the stochastic approaches were performed for this purpose. The contamination of raw materials may pose human health concerns, resulting in cancer risk above the threshold. Microbial risk is also above the safety threshold. Additional analysis would be significant as future research to better assess the microbial risk in biocomposite production. The framework has been effectively used for chemical and microbial risk assessment.

Innovative recovery of matrix layered double hydroxide from simulated acid mine wastewater for the removal of copper and cadmium from wastewater.

This study innovatively added biochar to optimize regulation in the neutralization process of simulated acid mine drainage (AMD) and recovered a new type of matrix layered double hydroxides (MLDH), which can be used to remove copper (Cu(II)) and cadmium (Cd(II)) from wastewater. A series of batch experiments show that MLDH with strong selective removal ability of Cu(II) and Cd(II) can be successfully obtained by adding biochar (BC) at pH = 5 end in the neutralization process. Kinetic and isotherm modeling studies indicated that the removal of Cu(II) and Cd(II) by the MLDH was a chemical multilayer adsorption process. The removal mechanism of Cu(II) and Cd(II) was further analyzed through related characterization analysis with contribution rate calculation: the removal rates of Cu(II) and Cd(II) by ion exchange were 42.7% and 26%, while that by precipitation were 34.5% and 49.9%, respectively. This study can provide a theoretical reference and experimental basis for the recovery and utilization of valuable by-products in AMD and the treatment of heavy metal wastewater.

In-situ growth of Mn-Ni3S2 on nickel foam for catalytic ozonation of p-nitrophenol.

In this study, a new catalyst for catalytic ozonation was obtained by in-situ growth of Mn-Ni3S2 nanosheets on the surface of nickel foam (NF). The full degradation of p-nitrophenol (PNP) was accomplished under optimal conditions in 40 min. The effects of material dosage, ozone dosage, pH and the presence of inorganic anions on the degradation efficiency of PNP were investigated. ESR analysis showed that singlet oxygen (1O2) and superoxide radical (O2•-) are the main contributors of PNP degradation. This study offers a new combination of supported catalysts with high efficiency and easy recovery, which provides a new idea for wastewater treatment.

Insight into soft chemometric computational learning for modelling oily-wastewater separation efficiency and permeate flux of polypyrrole-decorated ceramic-polymeric membranes.

Reliable modeling of oily wastewater emphasizes the paramount importance of sustainable and health-conscious wastewater management practices, which directly aligns with the Sustainable Development Goals (SDG) while also meeting the guidelines of the World Health Organization (WHO). This research explores the efficiency of utilizing polypyrrole-coated ceramic-polymeric membranes to model oily wastewater separation efficiency (SE) and permeate flux (PF) based on established experimental procedures. In this area, computational simulation still needs to be explored. The study developed predictive regression models, including robust linear regression (RLR), stepwise linear regression (SWR) and linear regression (LR) for the ceramic-polymeric porous membrane, aiming to interpret its complex performance across diverse conditions and, thus, develop its utility in oily wastewater treatment applications. Subsequently, a novel, simple average ensemble paradigm was explored to reduce errors and improve prediction skills. Prior to the development of the model, stability and reliability analysis of the data was conducted based on Philip Perron tests with the Bartlett kernel estimation method. The accuracy of the SE exhibited a high consistency, averaging 99.92% with minimal variability (standard deviation of 0.026%), potentially simplifying its prediction compared to PF. The modes were validated and evaluated using metrics like MAE, RMSE, Speed, and MSE, in addition to 2D graphical and cumulative distribution function graphs. The LR model emerged as the best with the lowest RMSE =0.21951, indicating superior prediction accuracy, followed closely by RLR with an RMSE = 0.22359. SWLR, while having the highest RMSE = 0.34573, marked its dominance in prediction speed with 110 observations per second. Notably, the RLR model justified a reduction in error by approximately 35.29% compared to SWLR. Moreover, the training efficiency of the LR model exceeded, demanding a mere 2.9252 s, marking a reduction of about 32.54% compared to SWLR. The improved simple ensemble learning proved merit over the three models regarding error accuracy. This study emphasizes the essential role of soft-computing learning in optimizing the design and performance of ceramic-polymeric membranes.

The Effects of Encapsulation on the In Vitro Anti-Clostridial Activity of Olive Mill Wastewater Polyphenolic Extracts: A Promising Strategy to Limit Microbial Growth in Food Systems.

Despite the technologies applied to food production, microbial contamination and chemical deterioration are still matters of great concern. In order to limit these phenomena, new natural approaches should be applied. In this context, the present study aimed to assess the antioxidant and anti-Clostridial effects of two different polyphenolic extracts derived from olive mill vegetation water, one liquid (LE) and one encapsulated (EE). The extracts have been preliminary characterized using Liquid Chromatography Quadrupole Time-Of Flight spectrometry. The Oxygen Radical Absorbance Capacity method was used to determine the antioxidant capacity, registering a higher value for EE compared to that for LE (3256 ± 85 and 2446 ± 13 µgTE/g, respectively). The antibacterial activity against C. perfringens, C. botulinum and C. difficile was studied by the agar well diffusion method, MIC and MBC determination and a time-kill test. The results confirm that EE and LE are able to limit microbial growth, albeit with minor effects when the phenolic compounds are encapsulated. Further studies are needed to evaluate the possible application of these extracts in food systems.

Plastic waste management in recycling facilities: Intentionally generated MPs as an emerging contaminant.

There is little knowledge about microplastic (MP) pollution in plastic recycling facility (PRF) wastewater. In this study, MPs in the wastewaters of four PRFs located in Türkiye were characterized for size, shape, color, and polymer types after sieving from 5,000 µm to the lowest 75 µm with seven sieves. The wet peroxide oxidation procedure was applied before attenuated total reflectance fourier transform infrared spectroscopy analysis for polymer identification. Polyethylene, and polypropylene were the dominant (75 % of total count) MP types within 22 polymer types. Average hit qualities of polymers increased from 69 % to above 84 % for the device software (OPUS) and open software (OpenSpecy). The abundance of MPs was determined as 53,987 MPs/L and 0.8 g MP/L for mixed PRFs 7,582 MPs/L and 4.6 g/L for the LDPE recycling facility, and 2,196 MPs/L and 0.06 g MPs/L for the granulation cooling water by count and weight, respectively. Small-sized MPs are found in the bottom sample much more than the surface and effluent samples in the washing tank. This indicated that MPs adsorbed the pollutants settled in the washing tank due to adsorbed pollution/biofilm. A maximum of 4.6 kg MP/ton of plastic recycled can be discharged as MPs that can be recovered. Considering the plastics recycling capacity, discharged MPs in these PRFs are possibly above 30,000 tons.

Characterization and evaluation of the anaerobic treatability of a dairy wastewater.

In this study, the characteristics, anaerobic treatability, and energy potential of wastewater samples taken from a dairy products industry were investigated. It was determined that the wastewater has a high organic load (COD = 2800 mg O2/L) and a large proportion of this load is biodegradable. The biochemical methane potential (BMP) value of wastewater was measured as 1118.71 ± 122 ml CH4/L. Volatile solids (VS) removal of 67.25 ± 4.98% was achieved during batch tests and the obtained methane yield was calculated as 411.59 ± 22.8 ml CH4/g VS. Peak methane formation rate and lag time of microorganisms were determined as 163.42 ± 3.83 ml CH4/g VS d and 0.584 ± 0.023 d, respectively. Rate constant for the first-order kinetic model was 0.384 ± 0.072 d-1. The volatile fatty acid (VFA) yield was measured as 155.19 mg COD/g VSS. It was concluded that the wastewater can be treated anaerobically without any inhibition and it has great energy potential. PRACTITIONER POINTS: Dairy wastewater has a large organic load and that most of the organics can be easily biodegradable. Although there are many components considered to be toxic for anaerobic treatment in wastewater, they were found to be very under the inhibition thresholds and did not pose any risk of toxicity. At a satisfactory level, organic matter removal and methane formation were observed in batch anaerobic tests. A rapid microbial adaptation was achieved and the system reached equilibrium in a short time without any acid accumulation. The electrical and caloric energy potentials of the obtained methane gas were calculated as 2.12 and 4.25 kWh/m3, respectively.

Influence of brassinosteroid and silicon on growth, antioxidant enzymes, and metal uptake of leafy vegetables under wastewater irrigation.

Vegetable cultivation under sewage irrigation is a common practice mostly in developing countries due to a lack of freshwater. Long-term usage provokes heavy metals accumulation in soil and ultimately hinders the growth and physiology of crop plants and deteriorates the quality of food. A study was performed to investigate the role of brassinosteroid (BRs) and silicon (Si) on lettuce, spinach, and cabbage under lead (Pb) and cadmium (Cd) contaminated sewage water. The experiment comprises three treatments (control, BRs, and Si) applied under a completely randomized design (CRD) in a growth chamber. BRs and Si application resulted in the highest increase of growth, physiology, and antioxidant enzyme activities when applied under canal water followed by distilled water and sewage water. However, BRs and Si increased the above-determined attributes under the sewage water by reducing the Pb and Cd uptake as compared to the control. It's concluded that sewerage water adversely affected the growth and development of vegetables by increasing Pb and Cd, and foliar spray of Si and BRs could have great potential to mitigate the adverse effects of heavy metals and improve the growth. The long-term alleviating effect of BRs and Si will be evaluated in the field conditions at different ecological zones.

Determination of phenytoin at trace levels in domestic wastewater and synthetic urine samples by gas chromatography-mass spectrometry after its preconcentration by simple liquid-phase microextraction.

This work presents a sensitive and accurate analytical method for the determination of phenytoin at trace levels in domestic wastewater and synthetic urine samples by gas chromatography-mass spectrometry (GC-MS) after the metal sieve-linked double syringe liquid-phase microextraction (MSLDS-LPME) method. A metal sieve was produced in our laboratory in order to disperse water-immiscible extraction solvents into aqueous media. Univariate optimization studies for the selection of proper extraction solvent, extraction solvent volume, mixing cycle, and initial sample volume were carried out. Under the optimum MSLDS-LPME conditions, mass-based dynamic range, limit of quantitation (LOQ), limit of detection (LOD), and percent relative standard deviation (%RSD) for the lowest concentration in calibration plot were figured out to be 100.5-10964.2 µg kg-1, 150.6 µg kg-1, 45.2 µg kg-1, and 9.4%, respectively. Detection power was improved as 187.7-folds by the developed MSLDS-LPME-GC-MS system while enhancement in calibration sensitivity was recorded as 188.0-folds. In the final step of this study, the accuracy and applicability of the proposed system were tested by matrix matching calibration strategy. Percent recovery results for domestic wastewater and synthetic urine samples were calculated as 95.6-110.3% and 91.7-106.6%, respectively. These results proved the accuracy and applicability of the proposed preconcentration method, and the obtained analytical results showed the efficiency of the lab-made metal sieve apparatus.

Biological wastewater treatment: a comprehensive sustainability analysis using life cycle assessment.

The research conducts a life cycle assessment (LCA) on wastewater treatment (WWT) methods-membrane bioreactor (MBR), soil biotechnology (SBT), and bio-electrochemical constructed wetlands (BCW)-in comparison with the conventional activated sludge process (ASP). Employing SimaPro v9.5 with a cradle-to-gate system boundary, the analysis utilizes the IMPACT 2002 + method, employing per cubic meter of treated wastewater as the functional unit. The analysis shows that SBT exhibits the lowest environmental impacts among the considered WWT methods. The global warming potential was 0.0996 kg CO2 eq. for SBT, 1.33 kg CO2 eq. for MBR, 0.131 kg CO2 eq. for BCW, and 0.544 kg CO2 eq. for ASP. BCW demonstrates a 75.91% decrease, while MBR exhibits a 144.48% increase compared to ASP. Notably, electricity consumption emerges as the primary contributor to environmental impact in MBR and ASP. The resource impact category varies with a 138.15% increase in MBR and an 83.41% decrease in SBT compared to ASP. Additionally, the research indicates that the high human health impact observed in MBR results mainly from increased carcinogens (0.00176 kg C2H3Cl eq.), non-carcinogens (0.01 kg C2H3Cl eq.), and ionizing radiation (3.34 Bq C-14 eq.). The findings underscore the importance of considering treatment efficiency and broader environmental implications in selecting WWT methods. As the world emphasizes sustainability, such LCA studies provide valuable insights for making informed decisions in wastewater management.

Group A Streptococcus pyogenes in wastewater: Applicability of wastewater-based epidemiology for monitoring the prevalence of GAS pharyngitis during the late COVID-19 pandemic phase.

Streptococcus pyogenes, Group A Streptococcus (GAS), is a human pathogen that causes a spectrum of diseases from mild to severe, including GAS pharyngitis, a common acute respiratory disease in developed countries. Although wastewater-based epidemiology (WBE) has been extensively used to monitor viral pathogens such as severe acute respiratory syndrome coronavirus 2, its applicability to S. pyogenes remains unexplored. This study was conducted to investigate the feasibility of detecting and quantifying S. pyogenes in wastewater by quantitative polymerase chain reaction (qPCR) and evaluate the applicability of WBE for monitoring the prevalence of GAS pharyngitis. A total of 52 grab influent samples were collected from a wastewater treatment plant in Japan once a week between March 2023 and February 2024. The samples were centrifuged, followed by nucleic acid extraction and qPCR for the S. pyogenes-specific genes speB and spy1258. Of the 52 samples, 90 % and 81 % were positive for speB and spy1258 genes, respectively, indicating the feasibility of S. pyogenes for wastewater surveillance. However, the percentage of quantifiable samples for speB gene was significantly higher in winter than in spring and summer. Similarly, the concentrations of both genes in wastewater samples were significantly higher in winter (speB, 4.1 ± 0.27 log10 copies/L; spy1258, 4.1 ± 0.28 log10 copies/L; One-way ANOVA, p < 0.01) than in spring and summer. Higher concentrations and detection ratios of S. pyogenes genes were observed during increased GAS pharyngitis cases in the catchment. Significant moderate correlations were observed between target gene concentrations and reported GAS pharyngitis cases. This study enhances the understanding role of WBE in monitoring and managing infectious diseases within communities.

Competence of algal consortia under municipal wastewater: remediation efficiency, photosynthetic performance, antioxidant defense mechanisms and biofuel production.

Utilizing monoalgal species for wastewater treatment is facing tremendous challenges owing to changing wastewater complexity in terms of physico-chemical characteristic, nutrient and metal concentration. The environmental conditions are also fluctuating therefore, the formation of robust system is of utmost importance for concomitant sustainable wastewater treatment and bioenergy production. In the present study, the tolerance and adaptability potential of algal consortia-1 (Chlorococcum humicola and Tetradesmus sp.) and consortia-2 (Chlorococcum humicola, Scenedesmus vacuolatus and Tetradesmus sp.) treated with municipal wastewater were examined under natural environmental conditions. The results exhibited that consortia-2 was more competent in recovering nitrate-nitrogen (82.92%), phosphorus (70.47%), and heavy metals (31-73.70%) from municipal wastewater (100%) than consortia-1. The results further depicted that total chlorophyll, carbohydrate, and protein content decreased significantly in wastewater-treated consortia-1 as compared to consortia-2. However, lipid content was increased by 4.01 and 1.17 folds in algal consortia-1 and consortia-2 compared to their respective controls. Moreover, absorption peak at 1740.6 cm-1 reflected higher biofuel-producing potential of consortia-1 as compared to consortia-2 as confirmed through FTIR spectroscopy. The results also revealed that consortia-2 showed the highest photosynthetic performance which was evident from the increment in the active photosystem-II reaction center (1.724 ± 0.068), quantum efficiency (0.633 ± 0.038), and performance index (3.752 ± 0.356). Further, a significant increase in photosynthetic parameters was observed in selected consortia at lag phase, while a noteworthy decline was observed at exponential and stationary phases in consortia-1 than consortia-2. The results also showed the maximum enhancement in ascorbic acid (2.43 folds), proline (3.34 folds), and cysteine (1.29 folds) in consortia-2, while SOD (1.75 folds), catalase (2.64 folds), and GR (1.19 folds) activity in consortia-1. Therefore, it can be concluded that due to remarkable flexibility and photosynthetic performance, consortia-2 could serve as a potential candidate for sustainable nutrient resource recovery and wastewater treatment, while consortia-1 for bio-fuel production in a natural environment. Thus, formation of algal consortia as the robust biosystem tolerates diverse environmental fluctuations together with wastewater complexity and ultimately can serve appropriate approach for environmental-friendly wastewater treatment and bioenergy production.

Towards a circular bioeconomy to produce methane by co-digestion of coffee and brewery waste using a mixture of anaerobic granular sludge and cattle manure as inoculum.

Coffee processing wastes, such as solid (pulp and husk) and wastewater, co-digested with industrial brewery wastewater, serve as excellent substrates for generating methane in the anaerobic digestion process. This study compared methane production using different compositions of cattle manure (CM) and granular sludge from an Upflow Anaerobic Sludge Blanket (UASB) reactor used in poultry wastewater treatment (GS). Four anaerobic batch reactors (500 mL) were assembled, A (50% CM and 50% GS), B (60% CM and 40% GS), C (70% CM and 30% of GS) and D (60% CM and 40% GS). Equal concentrations of substrates were added to all reactors: pulp and husk pretreated by hydrothermolysis (1 g L-1), coffee (10 g COD L-1) and brewery (1.5 g COD L-1) wastewaters. Assays A, B and C were supplemented with 2 g L-1 of yeast extract, except for assay D. The reactors were operated at 37 °C and pH 7.0. In assay B, the highest CH4 production of 759.15 ± 19.20 mL CH4 g-1 TS was observed, possibly favored by the synergistic interactions between cellulolytic bacteria Christensenellaceae_R-7_group and Methanosaeta archaea, as inferred by genes encoding enzymes related to acetoclastic methanogenesis (acetyl-CoA synthetase). Consequently, the electricity production potential of assay B (45614.08 kWh-1 year-1) could meet the energy demand of a farm producing coffee and beer, contributing to a positive energy balance concerning methane generation.

Toxic effects of nanoplastics on biological nitrogen removal in constructed wetlands: Evidence from iron utilization and metabolism.

Nanoplastics (NPs) in wastewaters may present a potential threat to biological nitrogen removal in constructed wetlands (CWs). Iron ions are pivotal in microbially mediated nitrogen metabolism, however, explicit evidence demonstrating the impact of NPs on nitrogen removal regulated by iron utilization and metabolism remains unclear. Here, we investigated how NPs disturb intracellular iron homeostasis, consequently interfering with the coupling mechanism between iron utilization and nitrogen metabolism in CWs. Results indicated that microorganisms affected by NPs developed a siderophore-mediated iron acquisition mechanism to compensate for iron loss. This deficiency resulted from NPs internalization limited the activity of the electron transport system and key enzymes involved in nitrogen metabolism. Microbial network analysis further suggested that NPs exposure could potentially trigger destabilization in microbial networks and impair effective microbial communication, and ultimately inhibit nitrogen metabolism. These adverse effects, accompanied by the dominance of Fe3+ over certain electron acceptors engaged in nitrogen metabolism under NPs exposure, were potentially responsible for the observed significant deterioration in nitrogen removal (decreased by 30 %). This study sheds light on the potential impact of NPs on intracellular iron utilization and offers a substantial understanding of the iron-nitrogen coupling mechanisms in CWs.

Simultaneous detection and characterization of common respiratory pathogens in wastewater through genomic sequencing.

Genomic surveillance of SARS-CoV-2 has given insight into the evolution and epidemiology of the virus and its variant lineages during the COVID-19 pandemic. Expanding this approach to include a range of respiratory pathogens can better inform public health preparedness for potential outbreaks and epidemics. Here, we simultaneously sequenced 38 pathogens including influenza viruses, coronaviruses and bocaviruses, to examine the abundance and seasonality of respiratory pathogens in urban wastewater. We deployed a targeted bait capture method and short-read sequencing (Illumina Respiratory Virus Oligos Panel; RVOP) on composite wastewater samples from 8 wastewater treatment plants (WWTPs) and one associated hospital site. By combining seasonal sampling with whole genome sequencing, we were able to concurrently detect and characterise a range of common respiratory pathogens, including SARS-CoV-2, adenovirus and parainfluenza virus. We demonstrated that 38 respiratory pathogens can be detected at low abundances year-round, that hospital pathogen diversity is higher in winter vs. summer sampling events, and that significantly more viruses are detected in raw influent compared to treated effluent samples. Finally, we compared detection sensitivity of RT-qPCR vs. next generation sequencing for SARS-CoV-2, enteroviruses, influenza A/B, and respiratory syncytial viruses. We conclude that both should be used in combination; RT-qPCR allowed accurate quantification, whilst genomic sequencing detected pathogens at lower abundance. We demonstrate the valuable role of wastewater genomic surveillance and its contribution to the field of wastewater-based epidemiology, gaining rapid understanding of the seasonal presence and persistence for common respiratory pathogens. By simultaneously monitoring seasonal trends and early warning signs of many viruses circulating in communities, public health agencies can implement targeted prevention and rapid response plans.

Are native microalgae consortia able to remove microplastics from wastewater effluents?

Wastewater Treatment Plants (WWTPs) are potential sources of microplastics (MPs) in the aquatic environment. This study aimed to investigate the potential of wastewater-native microalgae consortia to remove MPs from the effluent of two different types of WWTPs as a dual-purpose solution for MPs mitigation and biomass production. For that purpose, the occurrence of MPs from two types of WWTP effluents was analysed over one year. MPs were characterized in terms of morphology (microbead, foam, granule, irregular, filament and film), colour and size. The wastewater characterisation was followed by the removal of MP loads, using native microalgae consortia, pre-adapted to the wastewater effluent. Microalgae consortia evolved naturally through four mitigation assays, adapted to seasonal conditions, such as temperature, photoperiod, and wastewater composition. MPs were present in all the effluent samples, ranging from 52 to 233 MP L-1. The characterisation of MPs indicated a predominance of white and transparent particles, with irregular and filament shapes, mainly under 500 µm in size. The µFTIR analysis revealed that 43% of the selected particles were plastic, with a prevalence of polypropylene (PP) (34%) and polyethylene terephthalate (PET) (30 %). In the mitigation experiments, substantial biomass production was achieved (maximum of 2.6 g L-1 (d.w.)), with successful removal of MPs, ranging from 31 ± 25% to 82 ± 13%. These results show that microalgae growth in wastewater effluents efficiently promotes the removal of MPs, reducing this source of contamination in the aquatic environment, while generating valuable biomass. Additionally, the strategy employed, requires minimal control of culture conditions, simplifying the integration of these systems in real-world WWTP facilities for improved wastewater management.

The influence of light intensities and micropollutants on the removal of total coliforms and E. coli from wastewater in a flat-panel photobioreactor.

The presence of micropollutants and pathogens in sanitary wastewater and surface water is a growing concern that impacts public health, environmental balance and the maintenance of water supply services. To improve sanitary wastewater treatment, it is necessary to develop and improve sustainable technologies. Among the available options, microalgae-based systems stand out for their efficiency and generation of value-added byproducts. To study the impact of luminosity and the presence of micropollutants (13 selected) on the removal of E. coli and total coliforms from real anaerobically treated wastewater, a pilot flat-panel photobioreactor (50 L) was operated in batch mode in a tropical climate region. This is the first study to evaluate whether micropollutants interfere with coliform groups, considering a microalgae-based system and an experiment in a tropical climate region. E. coli had better removal (from 104 to 101 CFU 100 mL-1) than did total coliforms (from 104 to 103 CFU 100 mL-1). The removal of E. coli was more strongly linked to luminosity and temperature, while the removal of total coliforms was influenced by the presence of the selected micropollutants.

Migration and transformation modes of microplastics in reclaimed wastewater treatment plant and sludge treatment center with thermal hydrolysis and anaerobic digestion.

Microplastics in wastewater have been investigated globally, but less research on the migration and transformation of microplastics throughout wastewater and sludge treatment. This study investigated the fate of microplastics in a reclaimed wastewater treatment plant and a centralized sludge treatment center with thermal hydrolysis and anaerobic digestion. The results exhibited that the effluent microplastics of this reclaimed wastewater treatment plant were 0.75 ± 0.26 items/L. Approximately 98 % of microplastics were adsorbed and precipitated into sludge. After thermal hydrolysis, anaerobic digestion and plate and frame dewatering, the removal rate of microplastics was 41 %. Thermal hydrolysis was the most effective method for removing microplastics. Polypropylene, polyamide and polyethylene were widely detected in wastewater and sludge. 30 million microplastics were released into the downstream river and 51.80 billion microplastics entered soil through sludge cake daily. Therefore, substantial microplastics still entered the natural environment despite the high microplastics removal rate of reclaimed wastewater and sludge treatment.