Treated Wastewater Samples Research Articles

Treatment of clinical laboratory sewage using a decentralized treatment unit and risk reduction for its reuse in irrigation using hybrid disinfection

The disinfection efficacy of standalone chlorine, UV and their combined approach (hybrid) was investigated for the coliform removal in BioKube 1 and 2 treated effluents collected from different environmental settings of clinical and domestic wastes. Chlorine and UV disinfection were applied to BioKube treated wastewater with doses from 0 to 4 mg L−1 and 0–166 mJ cm−2 respectively. Combined disinfection strategies were designed to reduce the dose of chlorine and UV and to exploit the synergistic effect of them. The culturable coliforms were enumerated in treated wastewater sample (control), immediately after (reduction), and 24 h post disinfections (regrowth) using culture media plating and colilert-18 media. Both the BioKube systems (1 and 2) were effective in achieving the strict norms of physicochemical parameters, but not following the coliform counts of treated effluent for reuse in irrigation. A hybrid strategy of chlorine followed by UV was found to be the most effective among various standalone and combination approaches for the removal of coliforms (>4 log ER or <1000 CFU/100 mL) from both the treated effluents. However, coliform present in treated effluent of BioKube 1 were resisting (regrowth) against all kind of applied disinfectants except chlorine followed by UV dose at or more than 0.5 mg L−1 + 41 mJ cm−2. Limited reports are available on hybrid disinfection approaches with decentralized packaged sewage treatment units and this study would help to adopt as an effective tertiary treatment strategy for reuse of treated sewage for irrigation while ensuring public health safety.

Surveillance of multidrug-resistant tuberculosis in sub-Saharan Africa through wastewater-based epidemiology

The spread of multidrug-resistant tuberculosis (MDR-TB) is a serious public health issue, particularly in developing nations. The current methods of monitoring drug-resistant TB (DR-TB) using clinical diagnoses and hospital records are insufficient due to limited healthcare access and underreporting. This study proposes using Wastewater-Based Epidemiology (WBE) to monitor DR-TB in six African countries (Ghana, Nigeria, Kenya, Uganda, Cameroon, and South Africa) and examines the impact of treated wastewater on the spread of TB drug-resistant genes in the environment. Using droplet-digital polymerase chain reaction (ddPCR), the study evaluated untreated and treated wastewater samples in selected African countries for TB surveillance. There was a statistically significant difference in concentrations of genes conferring resistance to TB drugs in wastewater samples from the selected countries (p-value<0.05); South African samples exhibited the highest concentrations of 4.3(±2,77), 4.8(±2.96), 4.4(±3,10) and 4.7(±3,39) log copies/ml for genes conferring resistance to first-line TB drugs (katG, rpoB, embB and pncA respectively) in untreated wastewater. This may be attributed to the higher prevalence of TB/MDR-TB in SA compared to other African countries. Interestingly, genes conferring resistance to second-line TB drugs such as delamanid (ddn gene) and bedaquiline (atpE gene) were detected in relatively high concentrations (4.8(±3,67 and 3.2(±2,31 log copies/ml for ddn and atpE respectively) in countries, such as Cameroon, where these drugs are not part of the MDR-TB treatment regimens, perhaps due to migration or the unapproved use of these drugs in the country. The gene encoding resistance to streptomycin (rrs gene) was abundant in all countries, perhaps due to the common use of this antibiotic for infections other than TB. These results highlight the need for additional surveillance and monitoring, such as WBE, to gather data at a community level. Combining WBE with the One Health strategy and current TB surveillance systems can help prevent the spread of DR-TB in populations.

Improved disinfection performance for 280 nm LEDs over 254 nm low-pressure UV lamps in community wastewater

Ultraviolet (UV) disinfection has been incorporated into both drinking water and wastewater treatment processes for several decades; however, it comes with negative environmental consequences such as high energy demands and the use of mercury. Understanding how to scale and build climate responsive technologies is key in fulfilling the intersection of UN Sustainable Development Goals 6 and 13. One technology that addresses the drawbacks of conventional wastewater UV disinfection systems, while providing a climate responsive solution, is UV light emitting diodes (LEDs). The objective of this study was to compare performance of bench-scale 280 nm UV LEDs to bench-scale low pressure (LP) lamps and full-scale UV treated wastewater samples. Results from the study demonstrated that the UV LED system provides a robust treatment that outperformed LP systems at the bench-scale. A comparison of relative energy consumptions of the UV LED system at 20 mJ cm−2 and LP system at 30 and 40 mJ cm−2 was completed. Based on current projections for wall plug efficiencies (WPE) of UV LED it is expected that the energy consumption of LED reactors will be on par or lower compared to the LP systems by 2025. This study determined that, at a WPE of 20%, the equivalent UV LED system would lead to a 24.6% and 43.4% reduction in power consumption for the 30 and 40 mJ cm−2 scenarios, respectively.

Multivariate analysis of heavy metals in pharmaceutical wastewaters of National Industrial Zone, Rawat, Pakistan

Water is the basic necessity of life, and its quality affects biological processes. Anthropogenic activities increase concentration of harmful pollutants like heavy metals in the environment. The current study is the first attempt for the assessment of heavy metals in the wastewaters released from pharmaceutical industries of the National Industrial Zone, Rawat, Pakistan. The metal concentrations depicted the following trend: Fe » Zn > Ni > Pb > Mn > Cr6+ > Cd > Cu. Mn, Cu and Zn were recorded within the maximum permissible limits of Pakistan National Environmental Quality Standards (Pak-NEQS) and World Health Organization (WHO) in all the pharmaceutical wastewater samples; but Cd, Pb, Fe, Cr6+ and Ni surpassed one or both the admissible limits which can be the potential threat to the underground water resources, aquatic life and human health. The highest concentration was detected for Fe (10.86 ± 0.01 mg.L−1) in the wastewater sample of MB-12, which was much higher than the maximum NEQS limit of 2 mg.L−1. Maximum significant correlations were observed for Cr with various water quality parameters, including dissolved oxygen, phosphates, salinity and Cu during Pearson's correlation analysis. Multivariate techniques including cluster analysis and principal factor analysis were used to extract the latent information from the data set to assess the water quality. Three principal factors were extracted during factor analysis containing high positive factor loadings of Cd, Fe; Cu, Mn; and Pb in the principal factors 1, 2 and 3 respectively, indicating the contribution of the anthropogenic and industrial operations in the water contamination due to the discharge of improperly treated or untreated pharmaceutical wastewater. Cluster analysis based dendrogram resulted in the formation of single cluster containing reverse osmosis treated wastewater samples along with the untreated wastewaters which strongly recommends the need to adopt wastewater treatment methods with efficient processes for proper discharge of their pharmaceutical effluents into fresh waters, thus reducing the potential ecological hazards.

POM@PMO plastic electrode for phosphate electrochemical detection: a further improvement of the detection limit

The development of a highly sensitive electrochemical sensor (E-sensor) is described based on stand-alone plastic electrodes (PE) for phosphate detection, being an essential nutrient in the marine environment. The detection mechanism is based on the chemical affinity between polyoxomolybdate anions (POM) and orthophosphate to form an electroactive phosphomolybdate complex. The custom-made E-sensor was formulated with an organic octamolybdate derivative (TBA4Mo8O26) incorporated with periodic mesoporous organosilica (PMO) to obtain a significant improvement in the analytical performances of phosphate determination. This POM@PMO combination was found to be advantageous in the determination of low concentrations of phosphate in standard solutions ranging from 1 to 500 nM, using square wave voltammetry as the detection technique. This sensitivity enhancement can be attributed to the effect of hydrophobic PMO in loading more POM moieties, owing to its highly porous structure and charged shell. Consequently, the POM@PMO-PE sensor achieved a competitive sensitivity of 4.43 ± 0.14 μA.nM−1.cm−2 and a limit of detection of 0.16 nM with good selectivity against silicates. Finally, seawater and treated wastewater samples have been tested to validate the sensor response in comparison to the official method of phosphate determination.Graphical abstract

Kinetic modelling and process optimization of textile effluent treatment with bacterial gamma polyglutamic acid

Aim: The present study aims to synthesize gamma poly glutamic acid from the optimized starch-based glutamate-dependent medium for wastewater treatment with kinetic studies for an effective decolorization process. Methodology: Microbial coagulant (γ-PGA) was synthesized from the optimized glutamate-dependent medium with sago as a substrate and Bacillus subtilis as fermenter. Synthesized γ-PGA was harvested by ethanol precipitation and lyophilization method. The presence of γ-PGA was determined by UV-visible spectrum and ninhydrin analysis and its flocculating activity was screened by ninhydrin assay. Harvested γ-PGA was treated with different types of wastewater samples (Textile, tannery, dairy and sewage) in the preliminary screening. Process optimization was performed to screen the maximal decolorization for textile effluent (light and dark color). The physical and chemical characterization of treated wastewater samples with kinetic studies was performed to improve the treatment process. Results: The synthesized γ-PGA weighed as 41.20 g l-1 from the fermented medium and its presence was confirmed by characterization techniques. The flocculating activity of synthesized γ-PGA was 40.56 and 58.78 % against the kaolin suspension. The maximal decolorization percentage was 59.58% for γ- PGA treatment against textile effluent. The significance of optimized parameters such as pH, temperature, rotation speed and contact time were determined in the treatment of textile effluents (light and dark color) with maximal reduction of solids profile COD and BOD concentration. Kinetic studies revealed that the isotherm Langmuir isotherm was fit for the experimental data with R2 as 0.9943, 0.9692 and Pseudo second order fitted with R2 as 0.9871 and 0.9594 respective to light and dark color effluent. Interpretation: This study confirmed the maximal yield of γ-PGA from a sago-based glutamate-dependent medium and revealed its effective flocculating and decolorization activity against textile effluent which suggest them as a better alternative coagulants. Key words: γ- PGA, Bacillus subtilis, Kinetic modelling, Process optimization

Phenol contaminated municipal wastewater treatment using date palm frond biochar: Optimization using response surface methodology

Phenol is classified as an emerging contaminant which can be very toxic even at low concentrations and should be removed from wastewaters before reaching the environment. In this study date palm frond and leaf were pyrolyzed at different temperatures to identify the best adsorbent (feedstock) and pyrolysis temperature to remove phenol from aqueous solutions. Date palm frond pyrolyzed at 600 °C, termed DPF600, achieved the highest phenol removal rates of 64% and adsorption capacity of 15.93 mg/g. Response surface methodology approach using Box-Behnken design was implemented to obtain the optimal pH (6), contact time (20 h) and dosage (0.1 g) for the maximum phenol adsorption. A predicted adsorption capacity was found as 16.62 mg/g which was in close agreement with the experimental adsorption capacity of 17.38 mg/g. Isotherm and kinetic models in both linear and non-linear forms indicated that Freundlich model (R2 = 0.99, χ2 = 0.02, RMSE = 1.09) and pseudo-second order model (R2 = 0.99, χ2 = 0.85, RMSE = 5.41) fit best the obtained experimental data. Thermodynamics calculations affirmed that the adsorption of phenol onto DPF600 biochar was endothermic and spontaneous. The point of zero charge was found to be at 6.5 for DPF600 biochar. Scanning electron microscopy coupled with energy dispersive X-ray, Fourier transform infrared spectroscopy and X-ray diffraction confirmed adsorption of phenol onto DPF600 biochar. Application of DPF600 biochar to remove phenol from synthetic primary and secondary treated wastewater samples achieved 60 and 85% removal rates and 241 mg/g and 22.28 mg/g adsorption capacities, respectively. Regeneration studies showed promising adsorption capacities indicating the efficacy of DPF600 for the removal of phenol from wastewater.

Application of two fungal strains Aspergillus niger and Candida albicans in wastewater quality improvement

The nutrients Phosphorous, Nitrogen and Carbon are essential for aquatic life. However, in excess they also cause serious problems. For this reason, wastewater treatment must meet nutrient effluent limits. A wastewater sample was taken near Dhahibah village from the Erbil wastewater channel in the north of Iraq. In this experiment, pure cultures of Aspergillus niger and Candida albicans were used to treat wastewater. Samples were measured for physicochemical parameters like EC, pH, Phosphate, Nitrate, Nitrite, and BOD5 using standard methods every third day during 21 days of experiment. The results revealed that Aspergillus niger had the maximum efficiency in removing BOD5, NH4, NO3, and EC (87.27, 89.57, 83.52, and 78.49%) respectively. On the other hand, during the experimental period, Candida albicans had the maximum efficiency in decreasing PO4, and NO2, were (91.58% and 88.89%), respectively. Statistically, there were differences (P≤0.05) between the control sample and the treated wastewater sample for both fungal stains for all parameters during the experiment.

Adsorption of recalcitrant contaminants of emerging concern onto activated carbon: A laboratory and pilot-scale study

According to the World Health Organization (WHO), the definition of water quality indicators, including contaminants of emerging concern (CECs), associated with the development of multi-barrier approaches for wastewater treatment, are crucial steps towards direct potable reuse of water. The aims of this study were 1) quantifying twelve CECs (including pharmaceutical, stimulant, and artificial sweetener compounds) in both untreated and treated wastewater samples in a Brazilian wastewater treatment plant (WWTP) using bidimensional liquid chromatography coupled with tandem mass spectrometry, allowing the selection of five marker (i.e., priority) CECs; 2) evaluating the adsorption potential of such selected CECs [caffeine, hydrochlorothiazide, saccharin, sucralose (SUC), and sulfamethoxazole (SMX)] onto coconut-shell granular activated carbon (GAC); and 3) investigating the removal of the same CECs by a multi-barrier system (pilot-scale, 350 L h−1) treating the effluent of the WWTP and composed of reverse osmosis (RO), photoperoxidation (UV/H2O2), and filtration with GAC. Such technologies were tested separately and in binary or ternary combinations. Eleven and eight CECs were detected and quantified on the untreated and treated wastewater samples of the Brazilian WWTP, respectively. For the treated wastewater, the concentrations ranged from 499 ng L−1 (SMX) to 87,831 ng L−1 (SUC). The adsorption onto AC data fitted the Sips isotherm model, indicating monolayer chemisorption, which was also suggested by the mean adsorption energy values (>16 kJ mol−1). SMX and SUC were the most and the least adsorbed CECs (4.33 and 1.21 mg g−1, respectively). Concerning the pilot-scale treatment plant, the ternary combination (RO + UV/H2O2+GAC) removed >99% of the five marker CECs and promoted reductions on water color, turbidity, as well as on nitrogen and phosphorus concentrations. Further studies on water reuse could prioritize the selected marker CECs as quality indicators. While the removal of marker CECs is one of the WHO performance requirements, the RO + UV/H2O2+GAC system showed promising results as a first approach to direct potable reuse of water.

Development and validation of a direct injection liquid chromatography-tandem mass spectrometry method for the analysis of illicit drugs and psychopharmaceuticals in wastewater

A direct injection liquid chromatography-tandem mass spectrometry method was successfully developed for the analysis of 19 illicit drugs and psychopharmaceuticals in raw and treated wastewater. The method includes the analysis of stimulants and opioids, and antidepressant, antipsychotic, antianxiety, appetite suppressant and hallucinogen drugs. The method limits of quantification range from 5 – 59 ng L−1 and 2 – 38 ng L−1 in raw and treated wastewater, respectively. Analysis of raw and treated wastewater samples collected daily for a week from a wastewater treatment plant operating with oxidation ditch technology showed that codeine and tramadol were the drugs with the highest median mass concentrations in raw wastewater (1800 and 1000 ng L−1, respectively). The presence of some of the drugs in treated wastewater samples implies incomplete removal of illicit drugs and psychopharmaceuticals during wastewater treatment. This method offers an alternative to existing methods for faster screening of wastewater samples without the need for sample pre-concentration techniques, such as solid-phase extraction, with limits of detection in the low nanogram per litre range.

The Design of Ternary Composite Polyurethane Membranes with an Enhanced Photocatalytic Degradation Potential for the Removal of Anionic Dyes

Photocatalysis is an efficient and an eco-friendly way to eliminate organic pollutants from wastewater and filtration media. The major dilemma coupled with conventional membrane technology in wastewater remediation is fouling. In this study, the photocatalytic degradation potential of novel thermoplastic polyurethane (TPU) based NiO on aminated graphene oxide (NH2-GO) nanocomposite membranes was explored. The fabrication of TPU-NiO/NH2-GO membranes was achieved by the phase inversion method and analyzed for their performances. The membranes were effectively characterized in terms of surface morphology, functional group, and crystalline phase identification, using scanning electron microscopy, Fourier transformed infrared spectroscopy, and X-ray diffraction analysis, respectively. The prepared materials were investigated in terms of photocatalytic degradation potential against selected pollutants. Approximately 94% dye removal efficiency was observed under optimized conditions (i.e., reaction time = 180 min, pH 3–4, photocatalyst dose = 80 mg/100 mL, and oxidant dose = 10 mM). The optimized membranes possessed effective pure water flux and excellent dye rejection (approximately 94%) under 4 bar pressure. The nickel leaching in the treated wastewater sample was determined using inductively coupled plasma-optical emission spectrometry (ICP-OES). The obtained data was kinetically analyzed using first- and second-order reaction kinetic models. A first-order kinetic study was suited for the present study. Besides, the proposed membranes provided excellent photocatalytic ability up to six reusability cycles. The combination of TPU and NH2-GO provided effective strength to membranes and the immobilization of NiO nanoparticles improved the photocatalytic behavior.

Developing a novel Bifidobacterium phage quantitative polymerase chain reaction-based assay for tracking untreated wastewater

Microbial source tracking (MST) tools provide insights on fecal pollution levels in aquatic environments using predominantly quantitative PCR (qPCR) assays that target host-associated molecular marker genes. Existing wastewater-associated marker genes have shown limited or significant cross-reactions with non-human fecal samples. In this study, we mined the current Gut Phage Database (GPD) and designed a novel untreated wastewater-specific Bifidobacterium phage qPCR assay (i.e., Bifi assay). The sensitivity and specificity of the Bifi marker genes were assessed by collectively analyzing untreated (n = 33) and treated (n = 15) wastewater and non-human fecal samples (i.e., Rabbit, mouse, cow, horse, pig, chicken, sheep, dog, deer, kangaroos; n = 113) in Shenzhen, Guangdong Province, China and Brisbane, Australia. Bifi assay revealed 100% host-specificity against non-human fecal samples collected from Shenzhen and Brisbane. Furthermore, this marker gene was also detected in all untreated and treated wastewater samples, whose concentrations ranged from 5.54 to 6.83 log10 GC/L. In Shenzhen, the concentrations of Bifi marker gene were approximately two orders of magnitude lower than Bacteroides (HF183/BacR287 assay) and CrAssphage (CPQ_56 assay). The concentration of Bifi marker gene in untreated wastewater from Brisbane was 1.35 log10 greater than those in Shenzhen. Our results suggest that Bifi marker gene has the potential to detect and quantify the levels of human fecal pollution in Shenzhen and Brisbane. If additional detection sensitivity is required for environmental studies, Bifi marker gene should be paired with either CrAssphage or HF183/BacR287 marker genes.

Impact of Electromagnetic Field on Bacterial Population and Physicochemical Properties of Cassava Wastewater

The release of industrial wastewaters into the environment is a major source of toxic contaminants causing global health and environmental challenges. This study aimed to investigate the impact of electromagnetic field (EMF) treatment on bacterial population and physicochemical characteristics of cassava wastewater. Cassava wastewater sample was collected from point source of a small-scale cassava industry in Akure, Nigeria. Sample was thereafter treated with EMF of varying intensities (70- 130nT) and bacterial population and physicochemical properties of raw and treated wastewater sample were determined using standard microbiological, physical and chemical analytical techniques. Results revealed a total bacterial count of 1.34 x 105cfu/ ml. Identity of bacterial genera isolated from wastewater were Enterobacter aerogenes, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi (Gram negative) while the Gram positive bacteria were Staphylococcus aureus, Bacillus cereus, Bacillus subtilis and Lactobacillus sp. Results also revealed that treatment of wastewater sample with EMF significantly reduced the bacterial load and physicochemical parameters of the sample and dependent on EMF intensity and duration of exposure. Results revealed a decline in bacterial population from 1.34 x 105- 1.0 x 104 at intensities of 70nT-130nT and exposure time of 0- 144hr with the lowest count obtained at 130nT and the highest at 70nT. This study concludes that the use of Electromagnetic Field holds promise as an effective, non-invasive and eco-friendly strategy to improve the physical, chemical and biological quality of wastewater before discharge into the environment.

A new highly sensitive micro-sensor for the ultra-traces analysis of paracetamol directly in water

In the present work, a simple, inexpensive and highly sensitive electrochemical micro-sensor was developed for trace detection of paracetamol (PAR) directly in water, using electrochemical preconcentration technique (EP) on a cavity microelectrode modified with carbon black nanoparticles (nCB/ CME). The results demonstrate that with an EP of PAR on nCB/ CME at 0 V for 900 s in BRS 0.04 M at pH = 7, the new proposed micro-sensor show two large linear response in ranges of 5 × 10-10 to 9 × 10-8 mol.L-1 and from 1 × 10-7 to 1 × 10-6 mol.L-1. The detection and quantification limits are estimated to be 1.4 × 10-10 and 4.3 × 10-10 mol.L-1, respectively. The performances of the new proposed nCB/ CME for the determination of PAR were compared to its performances without EP and the results reveal the importance of the application of EP in improving the electroanalytical characteristics. The applicability of the designed micro-sensor was successfully applied for the direct analysis of local tap water and treated wastewater samples spiked with trace PAR compounds with a satisfactory recovery (less than 4 %) and a relation standard deviation less than 5 %. It indicates that the electrochemical micro-sensors are an effective device for monitoring PAR concentrations directly in water without any pretreatment.

Use of Solar Still in Heavy Metals Removal from Kitchen Wastewater

Indiscriminate discharge of wastewater into the environment can lead to environmental pollution. Heavy metals present in wastewater can infiltrate into the ground to cause groundwater contamination. In this study, a solar still was employed in the removal of heavy metals from domestic wastewater. Five wastewater samples with high heavy metal contents were kept in a solar still and subjected to heat from the sun. The solar still was constructed using locally available materials. The concentration of Iron (Fe), Zinc (Zn), Manganese (Mn), Chromium (Cr) and Cadmium (Cd) in the untreated and treated wastewater samples were determined. The study revealed a drastic reduction in the heavy metal content of the treated wastewater, however, the heavy metal content of most of the treated wastewater samples did not fall within World Health Organization (WHO) limit for potable water. Remarkably, The Zn content of four out of the five treated wastewater samples fell within WHO limit for potable water except for sample 2 which witnessed a drastic reduction from 13.9 to 3.28 mg/L but still did not meet up with WHO limit of 3 mg/L. The treated wastewater can be safely discharged into the environment; however, further treatment is required to make the water safe for human consumption.

Use of Solar Still in Heavy Metals Removal from Kitchen Wastewater

Indiscriminate discharge of wastewater into the environment can lead to environmental pollution. Heavy metals present in wastewater can infiltrate into the ground to cause groundwater contamination. In this study, a solar still was employed in the removal of heavy metals from domestic wastewater. Five wastewater samples with high heavy metal contents were kept in a solar still and subjected to heat from the sun. The solar still was constructed using locally available materials. The concentration of Iron (Fe), Zinc (Zn), Manganese (Mn), Chromium (Cr) and Cadmium (Cd) in the untreated and treated wastewater samples were determined. The study revealed a drastic reduction in the heavy metal content of the treated wastewater, however, the heavy metal content of most of the treated wastewater samples did not fall within World Health Organization (WHO) limit for potable water. Remarkably, The Zn content of four out of the five treated wastewater samples fell within WHO limit for potable water except for sample 2 which witnessed a drastic reduction from 13.9 to 3.28 mg/L but still did not meet up with WHO limit of 3 mg/L. The treated wastewater can be safely discharged into the environment; however, further treatment is required to make the water safe for human consumption.

Sono-peroxi-coagulation (SPC) as an effective treatment for pulp and paper wastewater: Focus on pH effect, biodegradability, and toxicity

In a comparative approach toward treating real pulp and paper wastewater (PPWW), iron-based electro-chemical processes such as peroxi-coagulation (PC), electrocoagulation (EC), electro-Fenton (EF), and ultrasound-assisted PC, EC, and EF were investigated. Sono-peroxi-coagulation (SPC) process showed the best performance for treating the PPWW. The optimal results were achieved under reaction time 50 min, current density 140 mA, and pH = 2.0. Employing the SPC process for treating PPWW under optimal conditions, the best COD removal efficiency (81.7%) was achieved. Also, continuous pH adjustment of the solution, as compared to lack of adjustment, showed a significant influence on COD removal efficiency (more than 10%). The effect of pH on the SPC process and the kind of electro-chemical treatment process utilized, on biodegradability were investigated using BOD/COD ratio and average oxidation state (AOS). In comparison with other electro-chemical processes used in this study, the best biodegradability results were obtained for the SPC process in pH = 2, being 0.4 and 0.94 for BOD/COD ratio and AOS, respectively. SPC process compared to the sono EF process had superior COD removal efficiency and their difference in performance reached near 40%. The influence of sonication was obtained 11.3% and 9% for PC and EF processes respectively. In evaluating the toxicity, the best germination index of Raphanus sativus, irrigated by treated wastewater samples, was achieved 77.9% for the SPC process. The application of US for electrochemical process increased energy consumption and cost of process considerably. The sludge of SPC was also evaluated by Fourier transform infrared spectrum (FTIR), X-ray diffractometer (XRD) and field emission scanning electron microscope (FESEM).

Imprints of Lockdown and Treatment Processes on the Wastewater Surveillance of SARS-CoV-2: A Curious Case of Fourteen Plants in Northern India

The present study investigated the detection of severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2) genomes at each treatment stage of 14 aerobic wastewater treatment plants (WWTPs) serving the major municipalities in two states of Rajasthan and Uttarakhand in Northern India. The untreated, primary, secondary and tertiary treated wastewater samples were collected over a time frame ranging from under-lockdown to post-lockdown conditions. The results showed that SARS-CoV-2 RNA was detected in 13 out of 40 wastewater samples in Jaipur district, Rajasthan and in 5 out of 14 wastewater samples in the Haridwar District, Uttarakhand with the E gene predominantly observed as compared to the N and RdRp target genes in later time-points of sampling. The Ct values of genes present in wastewater samples were correlated with the incidence of patient and community cases of COVID-19. This study further indicates that the viral RNA could be detected after the primary treatment but was not present in secondary or tertiary treated samples. This study implies that aerobic biological wastewater treatment systems such as moving bed biofilm reactor (MBBR) technology and sequencing batch reactor (SBR) are effective in virus removal from the wastewater. This work might present a new indication that there is little to no risk in relation to SARS-CoV-2 while reusing the treated wastewater for non-potable applications. In contrast, untreated wastewater might present a potential route of viral transmission through WWTPs to sanitation workers and the public. However, there is a need to investigate the survival and infection rates of SARS-CoV-2 in wastewater.

Application of a fast and sensitive method for the determination of contaminants of emerging concern in wastewater using a quick, easy, cheap, effective, rugged and safe-based extraction and liquid chromatography coupled to mass spectrometry

The inefficiency of wastewater treatment plants (WWTPs) to remove contaminants of emerging concern (CECs) leads to their continuous release to the environment. Consequently, CECs are present at low concentrations in the treated wastewater (TWW), producing unpredicted and unwanted effects on living organisms as they are discharged into water receiving bodies. This work presents a fast and reliable method for the determination of CECs in TWW based on the innovative application of a QuEChERS (quick, easy, cheap, effective, rugged and safe) method for water extraction and determination by sensitive liquid chromatography coupled to quadrupole-linear ion trap tandem mass spectrometry (LC-QqLIT-MS/MS). The scope of the proposed QuEChERS-based method allows the monitoring of 107 CECs, including pharmaceuticals (58), antibiotics (16) and pesticides (33). The proposed method was successfully validated in urban TWW at two concentration levels (50 and 500 ng L−1) and it is a feasible alternative to conventional and time-consuming solid-phase extraction (SPE) methodologies. 89% of the CECs presented mean recovery values in the 70–120% range with relative standard deviations (RSDs) always < 20% (intra and inter-day precision), and limits of quantification (LOQs) in the range 5–500 ng L−1 (89% of the compounds showed a LOQ ≤ 50 ng L−1). The applicability of the method was demonstrated by the analysis of urban TWW samples (7 sampling events). In total, 35 CECs (23 pharmaceuticals, 2 antibiotics and 10 pesticides) were detected in the monitored samples with concentrations ranging from 5 to 677 ng L−1.

Pharmaceuticals and environmental risk assessment in municipal wastewater treatment plants and rivers from Peru

This is the first study dealing with removal of the pharmaceutical substances in municipal wastewater treatment plants (MWWTPs) from Peru and the impact of these compounds in surface waters receiving treated wastewater. To this aim, samples from MWWTP of Lima (Peruvian Coast), MWWTP of Cusco, Puno and Juliaca (Peruvian Highlands), as well surface water (confluence of Torococha and Coata rivers in Juliaca) were analyzed. A total of 38 target pharmaceuticals were included in this study and were determined by Liquid Chromatography coupled to tandem Mass Spectrometry (LC-MS/MS). Around 60% and 75% of the target pharmaceuticals could be quantified in surface water and MWWTPs, respectively. Acetaminophen was the drug found at the highest concentration, and it was present in all the treated wastewater samples reaching average values above 100 μg/L in the department of Puno. The gabapentin anti-epileptic drug (up to 11.85 μg/L in MWWTP Lima) and the antibiotics clarithromycin, trimethoprim, ciprofloxacin, sulfamethoxazole and azithromycin (1.86 to 4.47 μg/L in MWWTP Lima) were also found at moderate concentrations in the treated wastewater. In surface water, the highest concentration corresponded also to acetaminophen (28.70 μg/L) followed by sulfamethoxazole (4.36 μg/L). As regards the pharmaceuticals removal, data of this work showed that the MWWTP Cusco (aerobic biologic process by synthetic trickling filters as secondary treatment) was more efficient than the MWWTP Lima (a preliminary treatment that combines grilles, sand trap, degreaser-aerated and sieved of 1.0 mm). However, many pharmaceuticals (around 50% of the compounds investigated) presented concentrations in treated wastewater similar or even higher than in influent wastewater. The environmental ecological risk of pharmaceuticals was assessed based on calculated Risk Quotient (RQ) in the treated wastewater and surface water from the concentration data found in the samples. According to our data, three antibiotics (clarithromycin, ciprofloxacin, clindamycin) and the analgesic acetaminophen posed high environmental risk (RQ ≥ 1) on the aquatic environment. In the river, all antibiotics (except norfloxacin) as well as the analgesic-anti-inflammatory compounds acetaminophen, diclofenac posed a high environmental risk (RQ ≥ 1). Based on data reported in this work for the first time in water samples from Peru, it can be deduced that the treatment processes applied in important cities from Peru are not enough efficient to remove pharmaceuticals in wastewater. As a consequence, severe environmental risks associated to the presence of pharmaceuticals in treated wastewater and surface water are expected; so complementary treatment processes should be implemented in the MWWTPs for a more efficient elimination of these compounds.