Wastewater Treatment Plant Outlet Research Articles

Whole UVCB Tests Can Yield Biotic and Abiotic Degradation Kinetics of Known and Unknown Constituents for an Enhanced UVCB Degradation Profile

The green transition and move towards safe and sustainable-by-design chemicals entail the need for new methods to study the biodegradability of UVCBs (substances of Unknown or Variable composition, Complex reaction products and Biological materials). Standard simulation biodegradation tests have been developed for single substances and are generally not applicable for UVCBs. The aims of this study were (1) to combine a whole UVCB biodegradation test with a sensitive constituent specific analytical technique, (2) to measure biotic and abiotic degradation of known and unknown UVCB constituents and (3) to determine the impact of a WWTP discharge on the constituent specific biodegradation in stream water. Lavender oil and black pepper oil are of significance in the perfume and cosmetics industries and served as model UVCBs. Stream water sampled upstream and downstream of a wastewater treatment plant (WWTP) discharge point was used as inoculum (i.e., naturally and wastewater adapted bacterial consortia). Tests were conducted in gastight headspace vials and automated Arrow Solid Phase Microextraction GC-MS-scan was applied on unopened vials. Peak area ratios between biotic test systems and abiotic controls were used to determine primary biodegradation kinetics, and freshly spiked analytical references to separate biotic from abiotic degradation. Biodegradation half-times were below 20 days for all known (8-12) and unknown constituents (>78) in the essential oils. Dual column GC-MS analysis produced a level 2 identification of 16 unknown lavender constituents. Biodegradation kinetics were similar in inoculum taken before and after the WWTP outlet, confirming that native stream microorganisms were competent degraders.

Photodegradation potential of selected non-steroidal anti-inflammatory drugs in a middle-order Alpine river downstream of a wastewater treatment plant, during a year of enduring water scarcity

The year 2022 was characterised by significant water shortages and droughts in Italy, with the most pronounced impact observed in the North-Western regions, including Piemonte. In conditions of water scarcity, treated wastewater undergoes little dilution by natural flows and this can deeply affect the chemistry of water-poor rivers and streams. However, increased pollution by wastewater would be partially offset by fast photodegradation of pollutants in shallow water and by the longer time allowed to photochemical reactions if water flows more slowly. We assessed the latter phenomena in the Stura di Lanzo, a middle-order Alpine river tributary of the largest Italian river, the Po, and affected by a wastewater treatment plant (WWTP). In 2022, the concentration values of the photochemically significant parameters nitrate, nitrite, and DOC were usually higher downstream of the WWTP outlet, which could slightly favour indirect photodegradation reactions. Direct and indirect photodegradation was assessed for the non-steroidal anti-inflammatory drugs paracetamol, diclofenac, and naproxen, all undergoing rather fast photoreactions. Photochemistry model results show that the three compounds would undergo 10–40 % photodegradation in spring and summer along the stretch separating the wastewater outlet from the confluence of Stura into the Po. Photodegradation would continue in the latter, but other WWTPs might contribute additional pollution in the meanwhile. Albeit significant, photodegradation could only partially promote the elimination of the contaminants.

Pollution Characteristics and Multilevel Risk Assessments of Antibiotics in the Urban Rivers of Beijing, China

To comprehensively assess the pollution characteristics and ecological risks of antibiotics in the rivers in Beijing, the concentrations of 35 common antibiotics belonging to four categories were quantified by using solid phase extraction combined with high-performance liquid chromatography-tandem mass spectrometry. The ecological risks of antibiotics were evaluated using the methods of risk quotient (RQ) and joint probability curves (JPCs). The results showed that a total of 33 antibiotics were detected in the surface water of ten rivers in Beijing, and the total concentrations of antibiotics ranged from N.D. to 1 573.57 ng·L-1. Sulfamethoxazole showed the highest concentration (N.D.-160.04 ng·L-1), followed by sulfadiazine (0.09-147.90 ng·L-1) and ofloxacin (0.28-94.72 ng·L-1). There were 16 antibiotics with a detection frequency greater than 50.0 %. The RQ method showed that there were 12 antibiotics with potential ecological risks. Tetracycline, clarithromycin, and trimethoprim showed the highest risks, with RQs of 3.99, 1.86, and 1.01, respectively. The risks of antibiotics at the outlets of wastewater treatment plants were higher than those in mainstream rivers. The PNEC exceedance rates of tetracycline, clarithromycin, and trimethoprim were above 2.3 %. Based on JPCs, the maximum risk product of clarithromycin was 1.66 %, and it showed low risks to 0.3 %-7.0 % of species. The risks of other antibiotics could be ignored. The detection frequency, distribution of concentrations, most sensitive species, and species sensitivity distribution of antibiotics had important impacts on the ecological risk assessment. Using the multilevel ecological risk assessment strategy can effectively avoid inadequate protection and overprotection and is also conducive to the hierarchical and zoning management of antibiotics throughout the region.

Analysis of Inlet and Outlet Wastewater Quality in WWTP Djoelham Regional General Hospital Binjai City

Hospitals produce quality liquid waste that is not by the standard value of quality standards that can pollute the environment. Indonesia is estimated to produce 48,985.70 tons of hospital liquid waste/per day. This study aims to determine the quality of inlet and outlet wastewater as well as the methods used by the Wastewater Treatment Plant (WWTP) of Djoelham Hospital, Binjai City. This study used qualitative types with observational methods. The research sample was taken from two points, namely the inlet point and the WWTP outlet point with BOD, COD, TSS, and pH parameters. Sampling technique using Composite Sampling. Data processing and analysis is carried out by statistical means. As well as data presented in the form of tables and line graphs. This research was conducted at Djoelham Hospital in Binjai City from March to May 2023. The results showed that the quality of wastewater in the parameters of BOD, COD, TSS, and pH in the inlet basin was by the quality standards of the Minister of Environment Regulation Number 5 of 2014, except for the value of TSS parameters in April 31 mg / l and May 35 mg / l. The quality of wastewater in the outlet basin based on the STORET method with a total score of 0 is classified as Class A (very good) or has met the quality standard value of the Minister of Environment Regulation Number 5 of 2014. Based on calculations, the average value of effectiveness of BOD (13.53%), COD (11.22%), and TSS (49.79%) was obtained. The WWTP method uses 2 methods, the aerobic and anerob methods. It is expected that the hospital will check the quality of inlet and outlet wastewater at least once every 1 month by PERMENLH Number 5 of 2014.

Modeling of wastewater treatment plant in Hama city using regression and regression trees

Background: Modeling of wastewater treatment plants is necessary to predict their later works. In this research, three methods were compared to predict some parameters at the outlet of wastewater treatment plant in Hama city in Syria. Methods: In this paper, three methods (linear regression, power regression, and regression trees) to model wastewater treatment plant in Hama city were compared to predict the parameters at the outlet of the plant (cBOD5out, CODout, TSSout) in terms of the parameters at the inlet of the plant (Qin, cBOD5in, CODin, TSSin). Results: When predicting cBOD5out, the values of RMSE of the test data set were 4.4105, 4.3875, and 3.8418; when predicting CODout, the values of RMSE of the test data set were 6.9325, 6.8003, and 5.3232; and when predicting TSSout, the values of root mean squared error (RMSE) of the test data set were 3.7781, 3.6936, and 3.2391 using linear regression, power regression, and regression trees (RTs), respectively. Conclusion: According to the results, the RTs outperforms in predicting cBOD5out, CODout, and TSSout because this method achieved the least RMSE of the test data set.

Radiological study of a wastewater treatment plant associated with radioiodine therapy at a hospital in West Java, Indonesia

Nuclear medicine (NM) services in Indonesia have rapidly developed due to the increasing number of patients, and this growth has been supported by standardized regulations in the field, including the management of solid waste generated. However, multiple reports indicate that licensing control does not regulate liquid waste disposal from patient excretions to protect personnel and the community from radiopharmaceutical exposure. One of the radiopharmaceuticals commonly used in NM and having the longest half-life among the radiopharmaceuticals used in NM is iodine 131(I-131). Thus, this study used a high-purity germanium detector to measure iodine-131 (I-131) activity in liquid waste from decay tanks, temporary collection channels, the hospital’s wastewater treatment plant (WWTP) outlet, and six points around the NM service and liquid waste treatment unit. Concentration measurements in three decay tanks were carried out sequentially every 12 h for 3 d, corresponding to the therapy period. The results showed that the I-131 activity levels in the decay tanks and temporary collection channels, before being mixed with liquid waste from other units, were 95.9 × 106 ± 4.4 × 106 Bq m−3. At the point where the liquid waste from other units was mixed, the activity level decreased significantly to 472 680 ± 22 160 Bq m−3, which was below the clearance level of 107 Bq m−3. However, the recorded concentration exceeded the standard for environmental radioactivity at the hospital’s WWTP outlet, namely 37 670 ± 2040 Bq m−3. The measurement results for I-131 in the air in the open space for two nuclear buildings was above the standard at 1.3 ± 0.27 Bq m−3. According to the RESRAD simulation, based on the initial dose taken from the liquid waste treatment outlet point, the accumulation of doses and the risk of cancer among workers and the community decreased within 3 months after the maximum exposure.

Avoidance behaviour of aquatic macroinvertebrates for real-time detection of micropollutant surge in wastewater effluents

Micropollutants are regularly detected at the outlets of wastewater treatment plants (WWTPs). Across urban and industrial WWTPs, monitoring directives only require assessment for a handful of chemicals via sampling methods that fail to capture the temporal variability in micropollutant discharge. In this study, we develop a biotest for real-time on-line monitoring of micropollutant discharge dynamics in WWTPs effluents. The selected biomonitoring device ToxMate uses videotracking of invertebrate movement, which was used to deduce avoidance behaviour of the amphipod Gammarus fossarum. Organism conditioning was set up to induce a state of minimal locomotor activity in basal conditions to maximise avoidance signal sensitivity to micropollutant spikes. We showed that with a standardised protocol, it was possible to minimise both overall movement and sensitivity to physio-chemical variations typical to WWTP effluents, as well as capture the spikes of two micropollutants upon exposure (copper and methomyl). Spikes in avoidance behaviour were consistently seen for the two chemicals, as well as a strong correlation between avoidance intensity and spiked concentration. A two-year effluent monitoring case study also illustrates how this biomonitoring method is suitable for real-time on-site monitoring, and shows a promising non-targeted approach for characterising complex micropollutant discharge variability at WWTP effluents, which today remains poorly understood.

Dissemination of carbapenemase-producing Enterobacterales through wastewater and gulls at a wastewater treatment plant in Sweden

Here we report the detection of carbapenemase-producing Enterobacterales (CPE) isolated from Swedish wastewater and gull faeces. CPE have not been detected in samples from animals in Sweden preceding this report. Sampling of wastewater treatment plant (WWTP) inlet and outlet, sedimentation basins, surface seawater from key aquatic bird habitats and freshly deposited gull faeces was done on six separate occasions during May to September 2021. Following broth enrichment, selective screening of putative CPE was performed on mSuperCarba™ (CHROMagar). Species identification was done with MALDI-TOF. Antimicrobial susceptibility testing was performed according to EUCAST. In total, seventeen CPE were verified by genome sequencing carrying blaGES-5, blaIMI-3, blaOXA-181 or blaOXA-244. The blaGES-5 was carried on IncP plasmids in four different species; Escherichia coli ST10 isolated from WWTP outlet, Raoultella ornithinolytica isolated from WWTP inlet, outlet and sedimentation basins as well as gull faeces collected at the WWTP and Klebsiella spp. isolates from WWTP inlet and outlet. The genetic environment surrounding blaGES-5 was similar in two Citrobacter freundii causing human infections. The blaIMI-3 was carried on IncFII(Yp) plasmids in four Enterobacter ludwigii, isolated from WWTP outlet and gull faeces collected at a recreational city park 2 km from the WWTP. The blaOXA-181 was located on a COLKP3 plasmid found in an E. coli, while blaOXA-244 was chromosomally located in an E. coli ST10, both isolated from WWTP inlet. Phylogenetic analysis of R. ornithinolytica and E. ludwigii isolates indicate that the gulls carried strains related to those identified in the WWTP samples. The results thus add to the increasing evidence of WWTPs as anthropogenic reservoirs for mobile genetic elements with antibiotic-resistance functionality. Such environments could profoundly impact the dissemination and spread of such genetic elements via for example aquatic birds, thereby warranting further study and surveillance.

Seasonal analysis of commonly prescribed antibiotics in Istanbul city.

Antibiotics are among the most common medicine groups since they are used to treat infectious diseases, as nutritional supplements in livestock breeding, and for preservation in the food industry. Turkey is among the highest antibiotic consumers in the world. In the present study, the most popular 14 antibiotics available in Turkey were monitored in one hospital sewage and two urban wastewater treatment plant influents and effluents seasonally in Istanbul province, the largest metropolitan center in Turkey. The present research aimed to develop a robust analytical method to determine 14 antibiotics, including six chemical groups, in environmental matrices which are considered significant antibiotic pollution sources, namely hospital sewage and urban wastewater. Solid-phase extraction (SPE) and UPLC-MS/MS analysis parameters included optimized column temperature, eluent, mobile phase, and flow rate. Three SPE cartridges were employed in recovery studies. The antibiotic recovery rates varied between 40 and 100%, and all analytes were identified within 3min with UPLC-MS/MS under optimal conditions. It was determined that method detection limits (MDLs) varied between 0.07 and 2.72µg/L for the antibiotics. In all seasons, the highest beta-lactam group antibiotic concentrations were identified in hospital sewage. The season with the greatest variety of antibiotics in urban wastewater was spring. Clarithromycin and ciprofloxacin were the antibiotics determined at the highest concentration in the influent and effluent of the wastewater treatment plant in all seasons. This study showed that the most widely used beta-lactam group antibiotics were found in high amounts in hospital sewage wastewater but in low concentrations in the treatment plants, and hence, it is seen that the degradability of beta-lactam group antibiotics was high. The presence of clarithromycin, ciprofloxacin, lincomycin, levofloxacin, and trimethoprim antibiotics in hospital sewage in higher amounts and also in inlet and outlet of wastewater treatment plants proves that those are resistant antibiotics.

Unaccounted Microplastics in the Outlet of Wastewater Treatment Plants—Challenges and Opportunities

Since the 1950s, plastic production has skyrocketed. Various environmental and human activities are leading to the formation and accumulation of microplastics (MPs) in aquatic and terrestrial ecosystems, causing detrimental effects on water, soil, plants, and living creatures. Wastewater treatment plants (WWTPs) are one of the primary MP management centers meant to check their entry into the natural systems. However, there are considerable limitations in effectively capturing, detecting, and characterizing these MPs in the inlet and outlet of WWTPs leading to “unaccounted MPs” that are eventually discharged into our ecosystems. In order to assess the holistic picture of the MPs’ distribution in the ecosystems, prevent the release of these omitted MPs into the environment, and formulate regulatory policies, it is vital to develop protocols that can be standardized across the globe to accurately detect and account for MPs in different sample types. This review will cover the details of current WWTP adoption procedures for MP management. Specifically, the following aspects are discussed: (i) several processes involved in the workflow of estimating MPs in the outlet of WWTPs; (ii) key limitations or challenges in each process that would increase the uncertainty in accurately estimating MPs; (iii) favorable recommendations that would lead to the standardization of protocols in the workflow and facilitate more accurate analysis of MPs; (iv) research opportunities to tackle the problem of ‘missing MPs’; and (v) future research directions for the efficient management of MPs. Considering the burgeoning research interest in the area of MPs, this work would help early scientists in understanding the current status in the field of MP analysis in the outlet of WWTPs.

Simultaneous Carbamazepine and Phosphate Removal from a Moving-Bed Membrane Bioreactor Effluent by the Electrochemical Process: Treatment Optimization by Factorial Design.

Pharmaceutical and personal care products are frequently used in various fields and released into water bodies from the outlets of wastewater treatment plants. These products can harm the environment and human health even at low concentrations. Carbamazepine (CBZ), the most persistent pharmaceutical, has frequently been found in surface waters that bypassed the secondary treatments of conventional activated sludge. In addition, the treatment of phosphate in wastewater by the electrochemical process has recently attracted much attention because of its ability to remove, recover, and prevent environmental problems associated with eutrophication. This study proposes using the electrochemical process as an advanced oxidation process to simultaneously treat CBZ and phosphate from the moving-bed membrane bioreactor effluent. The study includes a long-term survey of CBZ treatment efficiency and common parameters of synthetic wastewater in the moving-bed membrane bioreactor system. Afterward, the electrochemical process is applied as an advanced oxidation process for the simultaneous removal of CBZ and phosphate from the moving-bed membrane bioreactor. Under the investigated conditions, CBZ has proven not to be an inhibitor of microbial activity, as evidenced by the high extent of chemical oxygen demand and nutrient removal. Using a factorial design, the electrochemical process using Pt/Ti as anode and cathode under optimal conditions (reaction time-80 min, bias potential-3 V, and electrode distance-1 cm) resulted in as high as 56.94% CBZ and 95.95% phosphate removal, respectively. The results demonstrated the ability to combine an electrochemical and a moving-bed membrane bioreactor process to simultaneously remove CBZ and phosphate in wastewater.

Effects of wastewater effluent-borne nutrients on phytoplankton off the coast of Jeju Island.

The spatiotemporal distributions of nutrients in coastal waters surrounding eight wastewater treatment plants (WWTPs) in four seasons were investigated to determine the effects of WWTP effluents on seawater off Jeju Island, Korea. The highest concentrations of nutrients were observed in the outlets of WWTPs with relatively high ammonium concentrations among dissolved inorganic nitrogen (DIN). The reduced DIN (NO2- and NH4+)/total DIN ratios are used as a potential short-term index for marine environmental conditions. In seawater surrounding the WWTPs, relatively low nutrient concentrations were observed in spring and fall, due to enhanced biological production, which is closely linked to decreased N/P ratios. Because the highest WWTP effluent fluxes of ammonium in this study were similar to the fluxes of nutrients from submarine groundwater discharge, diffusion from bottom sediments, and discharge from land-based fish farm wastewater, WWTP effluent-derived nutrients are potentially important in oligotrophic environments and can be readily utilized by phytoplankton.

Spatiotemporal dynamics of microplastics in an urban river network area

Microplastics contamination in the environment is a global problem, but little is known about their dynamics in urban river networks, an important site of microplastics occurrence and harboring complex transport pathways. In this study, we investigated the spatiotemporal dynamic of microplastics in a typical urban river network in eastern China from December 2018 to September 2019. microplastics abundance (mean ± standard deviation) in the river network ranged from 2.3 ± 1.2 to 104.6 ± 5.6 particles/L and was significantly higher during the wet than during the dry season. The distribution of microplastics in the upper, middle, and lower reaches of the river network did not significantly differ, nor did the abundance of microplastics in the surface water vs. the bottom water. However, high abundances were determined in commercial and industrial areas, at a wastewater treatment plant outlet, in an urban canal, and in an urban-rural fringe area. The seasonal dynamics of the overall abundance of microplastics could be explained by the hysteresis effect of urban plastic production and the variation in regional precipitation. 78.2% of the microplastics were < 330 µm in size; the most common colors were blue and black, and the most common shapes were fragments and fibers. The polymer types of the microplastics were assessed using laser direct infrared (LDIR), a novel chemical imaging system that identified silicone, rubber, polytetrafluoroethylene, and polypropylene as the main components of the microplastics. A non-metric multidimensional scaling analysis (NMDS) based on the abundance of the polymer components across samples showed aggregations of sampling sites, that indicated the possible sources of the microplastics. Our study provides insights into the spatiotemporal dynamics of microplastics in an urban river network and suggests the potential of LDIR in the accurate quantitative analysis of microplastics in the environment.

Impact Assessment of the Wastewater Treatment Plants’ Discharges on Maritsa River

Data analysis of wastewater samples at the outlets of wastewater treatment plants (WWTPs) of Pazardzhik, Plovdiv and Svilengrad, which discharge into the Maritsa River is presented. Total monthly loads for 2017 at the outlets are calculated using the monthly averages for the concentrations of chemical oxygen demand, biochemical oxygen demand, total phosphorus and total nitrogen (TN) and the monthly averages for the flow rates. The contributions of the WWTPs to the total river loads emphasize that the impact of WWTPs of Pazardzhik and Plovdiv is significantly greater than WWTP of Svilengrad. Additionally, river water samples were collected before and after the discharge points of the WWTPs in August 2018 and analyzed for water quality parameters listed in Directive 75/440/EEC. Comparison between the river concentrations before the outlet of WWPT - Pazardzhik and after the last sampling point (the outlet of WWTP - Svilengrad) indicates an increase for all the studied parameters, except for Al and Cu. Based on the results obtained for TN, the category of the surface water is significantly deteriorated after discharge of the WWTP - Plovdiv. Wastewater effect on the river surface water is also estimated by using a battery of ecotoxicological tests. The results are presented and compared by the classical approach using categorization based on water quality indicators.

Assessment of wastewater biological treatment efficiency and mapping of WWTPs and LTPs in Algeria.

In this study, we present the evaluation of wastewater biological treatment by WWTPs (wastewater treatment plants) and LTPs (lagoon-based treatment plants) in Algeria using the results of analyzes of the samples of 108 stations, this work falls within the framework of a survey carried out by the research center in biotechnology (CRBt) in collaboration with ONA (National office of sanitation), and it reflects our interest in preserving the environment, in particular aquatic ecosystems, and determining the different sources of pollution and the most effective methods to cope with and for those that are well managed. The analyzes concerned various parameters of 108 stations. Temperature and pH were measured directly, in situ, using multi-parameter field probes. For the other parameters (MS, BOD5, COD, NO3, NO2, NH4, TP) the measurements were carried out in the laboratory according to standard and spectrophotometric methods. As well as through the reports of our field visits to the stations and the monitoring of purification processes. The results obtained show us that wastewater biological treatment is effective to a certain extent, whether in a WWTPs or LTPs. We have recorded that the reduction rates of the various pollutants from wastewater, are more efficient at the outlet of WWTPs than those of LTPs, even if we noted, at WWTP level, outgoing values ​​that do not comply with the standards for reuse and preservation of the receiving environment and higher than the Algerian standard for certain parameters. These results indicate that any use of this treated water, especially in agriculture, must take into account their specificity and the extent of its future impact, in particular the case where values ​​are higher than the Algerian and WHO standards. The online version contains supplementary material available at 10.1007/s40201-021-00682-1.

Performance Evaluation of Extended Aeration-Based Sewage Treatment Plants at NCT of Delhi, India

Due to urbanization and industrialization huge amount of wastewater is being generated, which is causing water pollution. Nowadays water pollution is a serious problem. The present study has been carried out to evaluate the efficiency of a waste water treatment plants with Extended Aeration Sludge Process (EASP). This has been done by examining the various physiochemical characteristics of wastewater (BOD, COD, TSS &amp; PO4), including a comparison of these characteristics at inlet and outlets of wastewater treatment plants and their variance over time. The examination of the competency of a technology is necessary for further optimization of the treatment units whilst complying with the Central Pollution Control Board (CPCB) requirements. In New Delhi’s Extended Aeration Plants are not working to their peak potential, but have still been able to treat the significant wastewater effectively. The study implies that the effluent released into the Yamuna River would not contribute to the river’s level of pollution.

Microplastic pollution in surface water and sediments in the urban section of the Vistula River (Poland)

The main hypothesis of this study was that the microplastic (MP) concentration would be higher in the city centre. The MP (<5 mm) abundance and distribution in the urbanized section of the Vistula River were examined. Samples were collected from three different sites: 1) the less urbanized part of the city, 2) the area close to the tributary outlet and wastewater treatment plant (WWTP), and 3) the city centre. The abundance of MPs in water ranged from 1.6 to 2.55 items L−1, whereas in the sediments, it varied from 190 to 580 items kg−1. The highest MP concentration was observed in the water collected in the city centre. However, in the case of sediments, the most polluted sample was collected from a sampling point located near the WWTP and tributary outlet. The diversity of the MPs abundance along the river was associated with the hydrological and sedimentological conditions, which was confirmed by the grain size analysis of sediments. The dominant type of MPs in both the water and sediment samples was fibre. The MPs were characterized by Raman spectroscopy as polystyrene (PS), polypropylene (PP), and a variety of other materials with different levels of deterioration. The images obtained by scanning electron microscopy (SEM) showed different disintegration features. Moreover, the SEM analyses revealed the occurrence of adhered particles and diatoms on the surface of MPs. The adsorption of various elements onto the MPs surface and the adhered particles was confirmed by energy-dispersive X-ray spectroscopy. The conducted studies emphasized the significance of the impact of large urban agglomerations, such as the Warsaw metropolitan area, on the concentration of MPs in rivers. Further studies are needed to better assess, for instance, the precise mode through which MPs in urban regions are transported by rivers to the seas.

Isolation and characterization of a multidrug-resistant Clostridioides difficile toxinotype V from municipal wastewater treatment plant.

Wastewater treatment plant (WWTP) is regarded as a potential source for transmission of Clostridioides difficile from urban areas into the surface water, through feces of human and animals. The aim of this study was to screen and characterize the C. difficile bacteria in inlet and outlet wastewater of different WWTPs in Tehran, Iran. Totally, 72 samples were collected from three different WWTPs (inlet site and outlet sites) during a year. C. difficile was isolated and characterized in terms of toxins, toxinotype, resistance profile and genes, and colonization factors using PCR. One C. difficile toxinotype V was isolated from the outlet samples. The isolate was susceptible to vancomycin but resistant to metronidazole, tetracycline, ciprofloxacin, and moxifloxacin using MIC Test Strips. The isolated C. difficile was toxigenic (tcdA, tcdB, cdtA, cdtB positive and CPE positive) and had tcdC-A genotype. No mutations were found in fliC and fliD. The slpA sequence type was 078 - 01. The C. difficile was positive for tetM, int, but negative for vanA, nim, and tndX genes. Mutations were not observed in gyrA and gyrB genes. This study provided evidence of presence of a multidrug-resistant C. difficile toxinotype V in one of the municipal WWTP. The transmission of such isolate to the environment and reuse of treated wastewater by human pose a threat to human health and dissemination of antibiotic resistant bacteria which are untreatable.

Occurrence and Origins of Cerium Dioxide and Titanium Dioxide Nanoparticles in the Loire River (France) by Single Particle ICP-MS and FEG-SEM Imaging

The need to quantify engineered nanoparticles (ENPs) in the environment is due to the increasing incorporation of these particles in the daily products, which threatens human health and can possibly impact natural systems. Ceria NPs (CeO2NPs) and titanium dioxide NPs (TiO2NPs) are two of the most used ENPs in the world. In this study their occurrence was determined in river waters with accurate and relevant techniques such as single particle ICP-MS (spICPMS). In the Loire River (France), the variation of both CeO2NPs and TiO2NPs could be assessed locally, with an increase of the concentrations near a wastewater treatment plant (WWTP) outlet as well as in a lake connected to the river and dedicated to outdoor activities. In the upstream river water, supposedly less impacted by NPs, 6.4 ± 1.2 x 104 part mL-1 Ce-bearing and 13.4 ± 1.8 x 104 part mL-1 Ti-bearing particles were measured. These values increased to 33.9 ± 3.4 x 104 part mL-1 Ce-bearing and 80.3 ± 3.4 x 104 part mL-1 Ti-bearing particles near the WWTP outlet. Equivalent size for sphere distributions ranged from 24 nm to 70 nm for CeO2 and from 80 nm to 500 nm for TiO2 in the river water. In the lake, a raise of the concentrations has been observed with 38.3 ± 2.0 x 104 part mL-1 and 71.6 ± 2.1 x 104 part mL-1 containing Ce and Ti, respectively, with similar size distributions. FEG-SEM imaging confirms the occurrence of Ce- and Ti-bearing particles in the water samples. On the contrary, NPs seem to undergo strong heteroaggregation in the Loire river water. The Ce/La elemental ratios does not evolve from upstream to downstream the WWTP outlet, suggesting that a natural origin cannot be excluded to explain the increase observed in NPs number concentration. On the contrary, the Ce/La ratio increases in the outdoor activities center, which suggests the contribution of NPs potentially related to the cars parked nearby. Besides, elemental ratios Ti/V and Ti/Y have been assessed to highlight an anthropogenic source of Ti in both sampling sites, possibly to the sunscreens used during the summer.

Bacterial diversity in superintensive vanname shrimp aquaculture wastewater treatment plants in Barru and Takalar Regencies

Super intensive wastewater treatment plant (WWTP) is needed to manage wastewater from aquaculture activities before being discharged into the waters. This study aims to determine the diversity of bacterial species in the WWTP super intensive vanname shrimp culture plots located in Barru and Takalar Regencies. The research method was designed by using a survey method in the WWTP super-intensive shrimp cultivation plot in Lajange Village, Mallusetasi District, Barru Regency, and Punanga Village, Takalar Regency. Sampling of DNA from water was carried out every two weeks for one culture cycle by filtering water from the WWTP outlet. The samples obtained were then DNA-extracted using cTAB dTAB DNA extraction kit (Iq2000). Quality of the DNA obtained was measured and analyzed using a genquan machine. Next Generation Sequencing (NGS) analysis was carried out by sending the DNA samples to a commercial company (Genetics Science laboratory) for the analysis. The results showed that the highest relative diversity of samples from Barru was 60% unidentified, followed by vibrio, unidentified Chloroplast, Arcobacter, Pseudoalteromonas, Marinobacterium, Marivita, Thalassatolea, Phaeodactylibacter, and Thalassalituus. Likewise, the relative diversity of bacteria from Takalary originating from Takalar, the highest was also not identified, followed by Pseudoalteromonas, unidentified_Chloroplast, Vibrio, Marivita, Thalassotalea, Phaedactylibacter, Thalassolituus, Arcobacter, and Tenacibaculum. It appears that the types of bacteria from the two sampling locations are still quite diverse and found probiotic bacteria, Pseudoalteromonas, that are commonly used in the cultivation of vanname shrimp in both WWTP plots.