Raw Wastewater Samples Research Articles

Wastewater-Based Epidemiology of Enteric Viruses and Surveillance of Acute Gastrointestinal Illness Outbreaks in a Resource-Limited Region.

Acute gastrointestinal illness (AGI) continues to be an important cause of morbidity and mortality among all ages. This study applied the principles of wastewater-based epidemiology for the preventive identification of potential outbreaks of acute viral gastroenteritis and hepatitis A by analyzing the presence of human enteric viruses in influents of small municipal wastewater treatment plants (WWTPs) handling domestic sewage, together with public health reports of acute diarrheal and hepatitis A disease in Costa Rica during 2013. Raw wastewater samples were collected during four seasonal periods with different rainfall levels. The presence of five human enteric viruses (rotavirus A, norovirus GI, norovirus GII, enterovirus, and hepatitis A virus) was studied by endpoint and real-time polymerase chain reaction in influents of five WWTPs. Cases of AGI were analyzed using historical public health reports of endemic levels and quartile ranges for each administrative and territorial area where the WWTPs are located and for its surrounding counties. A tendency for a higher rate of positive viral tests was present 1 week before an increase of AGI cases. Epidemiological weeks categorized as Outbreak (above the 75th percentile) and Success (below the 25th percentile) showed statistically significant differences in terms of positive viral test rates (Wilcoxon test, P = 0.05). Virological monitoring of wastewater in small WWTPs is an appropriate model for epidemiological surveillance of diarrheal and hepatitis A diseases in low- and middle-resource countries.

Defining biological and biophysical properties of SARS-CoV-2 genetic material in wastewater

SARS-CoV-2 genetic material has been detected in raw wastewater around the world throughout the COVID-19 pandemic and has served as a useful tool for monitoring community levels of SARS-CoV-2 infections. SARS-CoV-2 genetic material is highly detectable in a patient's feces and the household wastewater for several days before and after a positive COVID-19 qPCR test from throat or sputum samples. Here, we characterize genetic material collected from raw wastewater samples and determine recovery efficiency during a concentration process. We find that pasteurization of raw wastewater samples did not reduce SARS-CoV-2 signal if RNA is extracted immediately after pasteurization. On the contrary, we find that signal decreased by approximately half when RNA was extracted 24–36 h post-pasteurization and ~90% when freeze-thawed prior to concentration. As a matrix control, we use an engineered enveloped RNA virus. Surprisingly, after concentration, the recovery of SARS-CoV-2 signal is consistently higher than the recovery of the control virus leading us to question the nature of the SARS-CoV-2 genetic material detected in wastewater. We see no significant difference in signal after different 24-hour temperature changes; however, treatment with detergent decreases signal ~100-fold. Furthermore, the density of the samples is comparable to enveloped retrovirus particles, yet, interestingly, when raw wastewater samples were used to inoculate cells, no cytopathic effects were seen indicating that wastewater samples do not contain infectious SARS-CoV-2. Together, this suggests that wastewater contains fully intact enveloped particles.

Comparison of five polyethylene glycol precipitation procedures for the RT-qPCR based recovery of murine hepatitis virus, bacteriophage phi6, and pepper mild mottle virus as a surrogate for SARS-CoV-2 from wastewater

Polyethylene glycol (PEG) precipitation is one of the conventional methods for virus concentration. This technique has been used to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater. The procedures and seeded surrogate viruses were different among implementers; thus, the reported whole process recovery efficiencies considerably varied among studies. The present study compared five PEG precipitation procedures, with different operational parameters, for the RT-qPCR-based whole process recovery efficiency of murine hepatitis virus (MHV), bacteriophage phi6, and pepper mild mottle virus (PMMoV), and molecular process recovery efficiency of murine norovirus using 34 raw wastewater samples collected in Japan. The five procedures yielded significantly different whole process recovery efficiency of MHV (0.070%–2.6%) and phi6 (0.071%–0.51%). The observed concentration of indigenous PMMoV ranged from 8.9 to 9.7 log (8.2 × 108 to 5.6 × 109) copies/L. Interestingly, PEG precipitation with 2-h incubation outperformed that with overnight incubation partially due to the difference in molecular process recovery efficiency. The recovery load of MHV exhibited a positive correlation (r = 0.70) with that of PMMoV, suggesting that PMMoV is the potential indicator of the recovery efficiency of SARS-CoV-2. In addition, we reviewed 13 published studies and found considerable variability between different studies in the whole process recovery efficiency of enveloped viruses by PEG precipitation. This was due to the differences in operational parameters and surrogate viruses as well as the differences in wastewater quality and bias in the measurement of the seeded load of surrogate viruses, resulting from the use of different analytes and RNA extraction methods. Overall, the operational parameters (e.g., incubation time and pretreatment) should be optimized for PEG precipitation. Co-quantification of PMMoV may allow for the normalization of SARS-CoV-2 RNA concentration by correcting for the differences in whole process recovery efficiency and fecal load among samples.

Investigation of drugs of abuse in educational institutions using wastewater analysis

Wastewater analysis was used to investigate drug prevalence in primary and secondary schools and institutes of higher education located in urban and non-urban areas of six municipalities in Slovenia. Seven-hour composite raw wastewater samples from 44 educational institutions, including 19 primary schools (6–15 yrs.), ten secondary schools (15–19 yrs.), nine higher education institutions (19+ yrs.) and six mixed secondary and higher education institutions (15+ yrs.), were collected at the end of the 2018/2019 academic year. Metabolic residues of licit drugs (nicotine and alcohol), medications of abuse (morphine, codeine and methadone) and illicit drugs (cannabis, cocaine, amphetamine, methamphetamine, ecstasy and heroin) were targeted in the study. The analysis was carried out using solid-phase extraction and direct injection combined ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Biomarkers of nicotine, alcohol and cannabis intake were the most frequently detected, indicating a high prevalence of these drugs. Morphine and codeine were also detected, while among the stimulants, benzoylecgonine had the highest detection frequency. Drug differences were found between different levels of educational institution, geographic location (inter-municipality comparison) and degree of urbanization. However, t-distributed stochastic neighbour embedding (t-SNE) revealed that the level of educational institution was the main factor influencing the differences in drug prevalence. Although a good agreement between data from this study and other studies implementing wastewater analysis was observed, there was a discrepancy with Slovenian epidemiological survey data. Finally, despite certain drawbacks of the method, its application to detect drug residues in educational institutions provides a non-invasive insight into drug use trends.

Analytical performance comparison of four SARS-CoV-2 RT-qPCR primer-probe sets for wastewater samples

Current studies have confirmed the feasibility of SARS-CoV-2 RNA detection by RT-qPCR assays in wastewater samples as an effective surveillance tool of COVID-19 prevalence in a community. Analytical performance of various RT-qPCR assays has been compared against wastewater samples based on the positive ratio. However, there is no systematic comparison work has been conducted for both analytical sensitivity and quantitative reliability against wastewater, which are essential factors for WBE. In this study, the detection performance of four RT-qPCR primer-probe sets, including CCDC-N, CDC-N1, N-Sarbeco, and E-Sarbeco, was systematically evaluated with pure synthetized plasmids, spiked wastewater mocks and raw wastewater samples. In addition to confirm RT-qPCR results, Nanopore sequencing was employed to delineate at molecular level for the analytical sensitivity and reproducibility of those primer-probe sets. CCDC-N showed high sensitivity and the broadest linearity range for wastewater samples. It was thus recommended to be the most efficient tool in the quantitative analysis of SARS-CoV-2 in wastewater. CDC-N1 had the highest sensitivity for real wastewater and thus would be suitable for the screening of wastewater for the presence of SARS-CoV-2. When applying the primer-probe sets to wastewater samples collected from different Australian catchments, increased active clinical cases were observed with the augment of SARS-CoV-2 RNA quantified by RT-qPCR in wastewater in low prevalence communities.

Novel techniques to determine dilution ratios of raw wastewater and wastewater treatment plant effluent in the 5-day biochemical oxygen demand test

The current 5-day biochemical oxygen demand (BOD5) test methods lack detailed information on sample dilution, which typically leads to an incorrect dilution ratio of samples and failed BOD5 testing. This study proposed an improved dilution technique that effectively determines the dilution ratios for raw wastewater and wastewater treatment plants (WWTPs) effluent. The numbers of raw wastewater and WWTPs effluent samples used in the BOD5 tests were 201 and 61, respectively. The experimental results demonstrated that both the raw wastewater and WWTPs effluent varied in BOD5 values with the sample dilution ratio, and these changes were more noticeable when the dissolved oxygen consumption ratio (DOCR) was less than 20% or when the dilution ratio was large. Assuming that the BOD5 value over the DOCR range of 40%–70% was true, the optimal DOCR range was 40%–90% for the raw wastewater and 40%–70% and 80%–90% for the WWTPs effluent, where the relative error of BOD5 values in these DOCR ranges was less than 10% depending on the dilution ratio. The correlation between the sample dilution ratio and the BOD5 value over the optimal DOCR range was considerably higher than that over the entire DOCR range. This was combined with the correlation equation between BOD5 and chemical oxygen demand to propose an equation that could determine more accurate sample dilution ratios for raw wastewater and WWTPs effluent compared to the conventional sample dilution methods for the BOD5 test.

A comparison of four commercially available RNA extraction kits for wastewater surveillance of SARS-CoV-2 in a college population

Localized wastewater surveillance has allowed for public health officials to gain a broader understanding of SARS-CoV-2 viral prevalence in the community allowing public health officials time to prepare for impending outbreaks. Given variable levels of virus in the population through public health interventions, proper concentration and extraction of viral RNA is a key step in ensuring accurate detections. With many commercial RNA extraction kits and methodologies available, the performance of 4 different kits were evaluated for SARS-CoV-2 RNA detection in wastewater, specifically focusing on their applicability to lower population densities such as those at university campus dorms. Raw wastewater samples were collected at 4 sites on a college campus over a 24 hour period as a composite sample. Included in these sites was an isolation site that housed students that tested positive for Covid-19 via nasopharyngeal swabs. These samples were analyzed using the following kits: Qiagen All Prep PowerViral DNA/RNA kit, New England BioLabs Monarch RNA MiniPrep Kit, and Zymo Quick RNA-Viral Kit, and the Zymo Quick-RNA Fecal/Soil Microbe MicroPrep Kit. All four sites were processed according to the manufacturer's guidelines. Extractions were then quantified with RT-qPCR one-step reactions using an N2 primer and a linearized plasmid standard. While the Zymo Quick-RNA Fecal/Soil Microbe MicroPrep Kit (also known as the Zymo Environ Water RNA Kit) only recovered approximately 73% (±38%) SARS-CoV-2 RNA compared to the Zymo Quick-RNA Viral kit, it was the most time efficient kit to yield comparable results. This extraction kit had a cumulative processing time of approximately 5 h compared, while the other three kits had processing times between approximately 9 and 9.5 h. Based on the current research, the most effective kits for smaller population densities are pellet based and include a homogenization, inhibitor removal, and RNA preservation step.

Effect of selected wastewater characteristics on estimation of SARS-CoV-2 viral load in wastewater

Wastewater-based epidemiology has been used as a tool for surveillance of COVID-19 infections. This approach is dependent on the detection and quantification of SARS-CoV-2 RNA in untreated/raw wastewater. However, the quantification of the viral RNA could be influenced by the physico-chemical properties of the wastewater. This study presents the first use of Adaptive Neuro-Fuzzy Inference System (ANFIS) to determine the potential impact of physico-chemical characteristics of wastewater on the detection and concentration of SARS-CoV-2 RNA in wastewater. Raw wastewater samples from four wastewater treatment plants were investigated over four months. The physico-chemical characteristics of the raw wastewater was recorded, and the SARS-CoV-2 RNA concentration determined via amplification with droplet digital polymerase chain reaction. The wastewater characteristics considered were chemical oxygen demand, flow rate, ammonia, pH, permanganate value, and total solids. The mean SARS-CoV-2 RNA concentrations ranged from 648.1(±514.6) copies/mL to 1441.0(±1977.8) copies/mL. Among the parameters assessed using the ANFIS model, ammonia and pH showed significant association with the concentration of SARS-CoV-2 RNA measured. Increasing ammonia concentration was associated with increasing viral RNA concentration and pH between 7.1 and 7.4 were associated with the highest SARS-CoV-2 concentration. Other parameters, such as total solids, were also observed to influence the viral RNA concentration, however, this observation was not consistent across all the wastewater treatment plants. The results from this study indicate the importance of incorporating wastewater characteristic assessment into wastewater-based epidemiology for a robust and accurate COVID-19 surveillance.

Capsid integrity RT-qPCR for the selective detection of intact SARS-CoV-2 in wastewater

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes have been detected in wastewater worldwide. However, the assessment of SARS-CoV-2 infectivity in wastewater has been limited due to the stringent requirements of biosafety level 3. The main objective of this study is to investigate the applicability of capsid integrity RT-qPCR for the selective detection of intact SARS-CoV-2 in wastewater. Three capsid integrity reagents, namely ethidium monoazide (EMA, 0.1–100 μM), propidium monoazide (PMA, 0.1–100 μM), and cis-dichlorodiammineplatinum (CDDP, 0.1–1000 μM), were tested for their effects on different forms (including free genomes, intact and heat-inactivated) of murine hepatitis virus (MHV), which was used as a surrogate for SARS-CoV-2. CDDP at a concentration of 100 μM was identified as the most efficient reagent for the selective detection of infectious MHV by RT-qPCR (CDDP-RT-qPCR). Next, two common virus concentration methods including ultrafiltration (UF) and polyethylene glycol (PEG) precipitation were investigated for their compatibility with capsid integrity RT-qPCR. The UF method was more suitable than the PEG method since it recovered intact MHV (mean ± SD, 38% ± 29%) in wastewater much better than the PEG method did (0.013% ± 0.015%). Finally, CDDP-RT-qPCR was compared with RT-qPCR alone for the detection of SARS-CoV-2 in 16 raw wastewater samples collected in the Greater Tokyo Area. Five samples were positive for SARS-CoV-2 when evaluated by RT-qPCR alone. However, intact SARS-CoV-2 was detected in only three positive samples when determined by CDDP-RT-qPCR. Although CDDP-RT-qPCR was unable to determine the infectivity of SARS-CoV-2 in wastewater, this method could improve the interpretation of positive results of SARS-CoV-2 obtained by RT-qPCR.

Coupled microalgal–bacterial biofilm for enhanced wastewater treatment without energy investment

In view of water-resource depletion, treated wastewater can serve as an alternative source for crop irrigation. However, conventional wastewater-treatment plants are energy-intensive and costly to construct and operate, especially for lower middle-income countries. The present study focused on improving the quality of wastewater by incorporating a coupled microalgal–bacterial biofilm (CMBB) treatment in wastewater ponds. Standard polyether sponges were dipped in raw wastewater samples to enhance biofilm development on them. The enriched sponges were used to treat wastewater, with or without external energy for aeration. Wastewater parameters were analyzed during the enrichment and treatment processes. The CMBB technology and aeration resulted in similar improvement of effluent quality, but the former saved on energy costs, and reduced total chemical oxygen demand (COD) by 36 % within 24 h and 71 % within 4 days; the values of biochemical oxygen demand (BOD), ammonium and phosphates decreased by 80 %, 64 % and 95 %, respectively, within 7 days. The resultant COD and BOD values were below the maximum allowed for reuse and discharge.

Viability of SARS-CoV-2 in river water and wastewater at different temperatures and solids content

COVID-19 patients can excrete viable SARS-CoV-2 virus via urine and faeces, which has raised concerns over the possibility of COVID-19 transmission via aerosolized contaminated water or via the faecal-oral route. These concerns are especially exacerbated in many low- and middle-income countries, where untreated sewage is frequently discharged to surface waters. SARS-CoV-2 RNA has been detected in river water (RW) and raw wastewater (WW) samples. However, little is known about SARS-CoV-2 viability in these environmental matrices. Determining the persistence of SARS-CoV-2 in water under different environmental conditions is of great importance for basic assumptions in quantitative microbial risk assessment (QMRA). In this study, the persistence of SARS-CoV-2 was assessed using plaque assays following spiking of RW and WW samples with infectious SARS-CoV-2 that was previously isolated from a COVID-19 patient. These assays were carried out on autoclaved RW and WW samples, filtered (0.22 µm) and unfiltered, at 4 °C and 24 °C. Linear and nonlinear regression models were adjusted to the data. The Weibull regression model achieved the lowest root mean square error (RMSE) and was hence chosen to estimate T90 and T99 (time required for 1 log and 2 log reductions, respectively). SARS-CoV-2 remained viable longer in filtered compared with unfiltered samples. RW and WW showed T90 values of 1.9 and 1.2 day and T99 values of 6.4 and 4.0 days, respectively. When samples were filtered through 0.22 µm pore size membranes, T90 values increased to 3.3 and 1.5 days, and T99 increased to 8.5 and 4.5 days, for RW and WW samples, respectively. Remarkable increases in SARS-CoV-2 persistence were observed in assays at 4 °C, which showed T90 values of 7.7 and 5.5 days, and T99 values of 18.7 and 17.5 days for RW and WW, respectively. These results highlight the variability of SARS-CoV-2 persistence in water and wastewater matrices and can be highly relevant to efforts aimed at quantifying water-related risks, which could be valuable for understanding and controlling the pandemic.

New psychoactive substances in several European populations assessed by wastewater-based epidemiology

Wastewater-based epidemiology (WBE) can be a useful tool to face some of the existing challenges in monitoring the use of new psychoactive substances (NPS), as it can provide objective and updated information. This Europe-wide study aimed to verify the suitability of WBE for investigating the use of NPS. Selected NPS were monitored in urban wastewater by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The main classical illicit drugs were monitored in the same samples to compare their levels with those of NPS. Raw composite wastewater samples were collected in 2016 and 2017 in 14 European countries (22 cities) following best practice sampling protocols. Methcathinone was most frequent (>65% of the cities), followed by mephedrone (>25% of the cities), and only mephedrone, methcathinone and methylone were found in both years. This study depicts the use of NPS in Europe, confirming that it is much lower than the use of classical drugs. WBE proved able to assess the qualitative and quantitative spatial and temporal profiles of NPS use. The results show the changeable nature of the NPS market and the importance of large WBE monitoring campaigns for selected priority NPS. WBE is valuable for complementing epidemiological studies to follow rapidly changing profiles of use of drugs.

First comprehensive study of alcohol consumption in Italy using wastewater-based epidemiology

Alcohol use has increased in the last years and is a priority public health issue worldwide. Wastewater-based epidemiology (WBE) is a reliable approach for estimating substance use at the population level and can complement population surveys and sales statistics to obtain objective and updated information on alcohol use in a community. This work reports the first nationwide study of alcohol consumption conducted in Italy by WBE, covering 11.4% of the Italian population. A total of 264 raw wastewater samples (24-h composite) were collected from 17 Italian cities in 2013–2014 and one large city (Milan) over a 7-year period (2013–2019). Besides of normal days, special periods/events (i.e. Halloween, Milan Fashion Week and summer holidays) were studied in Milan. The urinary biomarker of ethanol (namely, ethyl sulphate) was measured by liquid chromatography-tandem mass spectrometry and was used to estimate alcohol consumption. Results were statistically evaluated to assess spatial and temporal differences and were compared with data from other epidemiological indicators. In 2013, alcohol consumption was significantly higher in small cities than in large ones but no significant differences were observed in relation to the geographical position. An increase in alcohol use was observed in seven large cities from 2013 to 2014. The 7-year monitoring in Milan showed no marked changes, except for remarkable increases in 2014 and 2019. Alcohol consumption significantly increased (ca. 25%) during weekends in Italy and in Milan, and during special periods/events, for instance summer holidays and Halloween. WBE estimates were in agreement with national prevalence data, demonstrating that WBE is suitable for objectively evaluating geographic, annual and weekly patterns of alcohol consumption at local and national scales. WBE information would be helpful to implement and evaluate measures for reducing alcohol consumption and preventing the related health risks.

COVID-19 infection risk from exposure to aerosols of wastewater treatment plants

Fecal shedding of SARS-CoV-2 from COVID-19 patients and presence of the viral RNA in wastewater have extensively been reported. Some wastewater treatment plant (WWTP) processes generate aerosols which have the potential to transmit pathogenic microorganisms and present a health risk for exposed individuals. We analyzed the presence of viral RNA of SARS-CoV-2 in raw wastewater and air samples of WWTPs. The risk that may arise from exposure to virus-contaminated aerosols of wastewater was estimated by developing a quantitative microbial risk analysis (QMRA) method. SARS-CoV-2 was detected in 9 of 24 (37.5%) wastewater samples with a concentration about 104 genomic copies L−1. The viral RNA was also detected in 40% (6/15) of air samples. QMRA analysis showed a relatively high risk of SARS-CoV-2 infection for wastewater workers via exposure to the viral aerosols. The estimated annual infection risk ranged from 1.1 × 10−2 to 2.3 × 10−2 per person per year (PPPY) for wastewater workers which was higher than the reference level recommended by WHO (10−3 pppy). However, due to the lack of data on survival of SARS-CoV-2 in wastewater and its fate in aerosolized state, more research is needed to determine the importance of wastewater in transmission of COVID-19.

Isoprostanes in wastewater as biomarkers of oxidative stress during COVID-19 pandemic

Isoprostanes are the potential biomarkers of endogenous human metabolism and proven clinically to provide the quantitative measure of systematic oxidative injury. An ultra-performance liquid chromatography-tandem mass spectrometric analytical method capable of determining four biomarkers of oxidative stress (8-iso-PGF2α, 2,3-dinor-iPF2α-III, PGE2, and 5-iPF2α-VI) in wastewater was developed and validated. Isoprostanes were quantified in the range of 31.1–1270 ng/L in raw wastewater samples in two communities in western Kentucky and Tennessee during the first four months of the COVID-19 pandemic. Consistent detection of PGE2 and 5-iPF2α-VI in wastewater suggested that PGE2 and 5-iPF2α-VI can be a reliable biomarker of community oxidative anxiety. The higher 4-month average mass load of isoprostanes [(ranged from 22.9 mg/d/1000 people to 807 mg/d/1000 people] may be attributed to the elevated community level oxidative anxiety owing COVID-19 uncertainties. The average mass loads of PGE2 and 5-iPF2α-VI in a community were significantly increased (two-tailed p < 0.001) from the first month of COVID-19 pandemic to the second month; however, significantly decreased (two-tailed p < 0.001) in the third month. Wastewater-based-epidemiological determination of isoprostanes can be a near-real-time and cost-effective approach of a trend in community depression. This is the first report of the quantification of PGE2 and 5-iPF2α-VI in wastewater and estimation of the community level oxidative anxiety.

Emerging technologies for treatment of antibiotic residues from wastewater influent/effluent for sustainable environment: A case study with NFC-doped titania immobilized on polystyrene as an efficient technology

In this study, 5 urban and 2 industrial wastewater treatment plants (WWTPs) were investigated. Raw wastewaters and effluents of WWTPs were characterized in terms of both organic and inorganic pollutants and antibiotic residues. According to the analysis results; organic pollutants for raw wastewaters and influents in urban WWTP were measured between 412 and 921 ​mg ​L−1 for COD, 345–421 ​mg ​L−1 for TOC, 61–160 ​mg ​L−1 for COD, 48–83 ​mg ​L−1 for TOC, respectively. However, in industrial WWTPs, these values were determined in raw wastewaters between 1404 and 2367 ​mg ​L−1 for COD, 821–826 ​mg ​L−1 for TOC and in effluents between 272 and 408 ​mg ​L−1 for COD and 97–208 ​mg ​L−1 for TOC, respectively.In addition, in the characterization study of antibiotic residues by the results of HPLC/MS-MS measurements, the amounts of Ciprofloxacin (from the fluoroquinolones), Erythromycin (from the macrolides group) and Sulfamethoxasol (from the sulfonamide group), which are one of the three main groups of antibiotics in the waste water samples, were found in high amounts in both urban and industrial WWTPs despite the biological treatment process. More antibiotic residues (Erythromycin-ERY, Ciprofloxacin-CIP and Sulfamethoxasol-SMX) were detected in untreated raw wastewater compared to effluent wastewater. While CIP antibiotic was not found only one urban WWTP, the highest amounts in the effluents of 4 urban WWTPs were measured between 13,800 ​ng ​L−1 and 38,800 ​ng ​L−1. Moreover, ERY is only detected in high amount in one urban WWTP raw and effluent wastewater as 23,100 ​ng ​L−1 and 5430 ​ng ​L−1, respectively. The SMX was detected in 2 separates urban WWTPs at a value of 19,700 ​ng ​L−1 in the raw wastewater sample and at a value 10,100 ​ng ​L−1 in effluent sample of another urban WWTP. Antibiotic residue removal ratios after Advanced Oxidation Process using specially prepared NFC-doped TiO2 photocatalyst immobilized on polystyrene (PS) cup inner surface at amount 0.45 ​g were determined as 97%–~100% for CIP, 100% for ERY, 86%–~100% for SMX, 57%–64% for COD and 61,5%–72% for TOC, respectively.According to the above mentioned results, this study proved that photocatalytic oxidation processes performed under visible light with a specially prepared immobilized form (PS/Cup–NFC–0.45 ​g) photocatalyst provide higher antibiotic removal from both urban and industrial wastewater. Thus, these results showed us that if the application of NFC-doped Titania, immobilized on polystyrene, can be integrated with an appropriate reactor design on the real/pilot scale, this technology can be proposed as an efficient technology for sustainable environment.

Sol-gel preparation of bioactive nanoporous (Al&lt;SUB align="right"&gt;2O&lt;SUB align="right"&gt;3: CuO: SiO&lt;SUB align="right"&gt;2): dielectric properties and wastewater decontamination

The morphological and dielectric properties of bioactive sol-gel alumino-copper silicate nanoporous are characterised. It is characterised by sharp diffraction peaks confirming the high crystallinity. Alumino-copper silicate was utilised as a disinfecting agent for wastewater disinfection. The growth inhibitory effect of alumino-copper silicate sanitiser was investigated against various categories of microbial pathogens. Toxicity assay of fabricated alumino-copper silicate nanoporous was measured. The acquired results disclosed that target pathogenic microbes in the raw wastewater sample were inactivated when subjected to 100 mg/L of fabricated alumino-copper silicate. Likewise, results could not discover any deleterious and poisonous influences for the Vibrio fischeri bacterium and HEp-2 cell line of such nanostructures subsequently, it will be safe for use in water treatment. This investigation, therefore, recommends that the prepared alumino-copper silicate could be considered a future substitute marvellous and sustained-active disinfectant for the production of pathogenic free treated wastewater for recycling in many different applications.

Sol-gel preparation of bioactive nanoporous (Al&lt;SUB align="right"&gt;2O&lt;SUB align="right"&gt;3: CuO: SiO&lt;SUB align="right"&gt;2): dielectric properties and wastewater decontamination

The morphological and dielectric properties of bioactive sol-gel alumino-copper silicate nanoporous are characterised. It is characterised by sharp diffraction peaks confirming the high crystallinity. Alumino-copper silicate was utilised as a disinfecting agent for wastewater disinfection. The growth inhibitory effect of alumino-copper silicate sanitiser was investigated against various categories of microbial pathogens. Toxicity assay of fabricated alumino-copper silicate nanoporous was measured. The acquired results disclosed that target pathogenic microbes in the raw wastewater sample were inactivated when subjected to 100 mg/L of fabricated alumino-copper silicate. Likewise, results could not discover any deleterious and poisonous influences for the Vibrio fischeri bacterium and HEp-2 cell line of such nanostructures subsequently, it will be safe for use in water treatment. This investigation, therefore, recommends that the prepared alumino-copper silicate could be considered a future substitute marvellous and sustained-active disinfectant for the production of pathogenic free treated wastewater for recycling in many different applications.

Isolation of Bacteria with Purifying Potential and Application in the Treatment of Effluents from an Artisanal Palm Oil Mill in the Littoral Region of Cameroon

It is with the aim of solving the problem of generating large quantities of effluents from palm oil production in the littoral region of Cameroon that this study was carried out with the general objective of reducing the pollutant load of these effluents by using bacteria. To this end, raw palm oil mill wastewater samples were taken for their characterization by evaluating the in-situ (Temperature, pH and (CND) Conductivity) and ex-situ (SS (suspended solid), COD (chemical oxygen demand), BOD (biological oxygen demand) and O/F (oil and fat)) parameters. In addition, bacterial isolation and screening were carried out from samples of contaminated soil based on the production of lipolytic enzymes, the degradation of oils and fats and the reduction of the pollutant load. Results revealed that 28 isolates were able to reduce the pollution parameters of palm oil mill effluents of which D17, D22 and D23 seemed to be the best purifying isolates. The characterization of the POME (palm oil mill effluent), basing the temperature, pH, CND, O/F, SS, BOD and COD showed us values greater than the recommended rate. Partial characterization of these isolates revealed that D17 and D23 are bacteria that could reduce the polluting parameters of the effluents belonged to the Bacillus sp. genus and D22 to the Acinetobacter sp. genus. These results are satisfactory and the bacteria strains obtained could be used in bioremediation.

WASTEWATER-BASED EPIDEMIOLOGY AS AN ALLY IN THE FIGHT AGAINST THE COVID-19: A BRIEF REVIEW

Several researchers have detected the viral genome of SARS-CoV-2 in the stools of people (symptomatic or not) diagnosed with coronavirus disease-2019 (COVID-19). In domestic wastewater, this concentration can be between 19 and 5.5 x 106 viral genomes per liter of wastewater. Wastewater-based epidemiology (WBE) starts from the premise that it is possible to estimate the number of people infected by the new coronavirus within a given population group, by analyzing the amount of viral genome present in the wastewater produced by these people. This paper presents the procedures to estimate the number of COVID-19 cases from raw wastewater samples, discusses the main aspects that involve the WBE assay and presents a discussion based on the case studies applied to COVID-19 in some countries. Finally, there is a final discussion about the current situation and the main challenges for WBE to be applied efficiently for COVID-19, as an alternative to massive human testing, especially for developing and underdeveloped countries.