scholarly journals Impact of informal settlements and wastewater treatment plants on helminth egg contamination of urban rivers and risks associated with exposure

2020 ◽  
Vol 192 (11) ◽  
Author(s):  
Isaac Dennis Amoah ◽  
Sheena Kumari ◽  
Poovendhree Reddy ◽  
Thor Axel Stenström ◽  
Faizal Bux

AbstractThe quality of surface water could be influenced by both anthropogenic and natural factors. This study was designed to determine the impact of informal settlement and wastewater treatment plants on helminth egg contamination of urban rivers and the risks associated with everyday use. We also ascertained the accumulation of these eggs in the river sediments. The study was carried out in two rivers in the eThekwini Municipality of South Africa. Grab samples were taken at different points over a 10-month period. Ascaris spp., hookworm, Toxocara spp., Trichuris spp. and Taenia spp. were the helminth eggs detected in both the water column and sediments, with mean Ascaris spp. eggs of 0–6.3 (± 5.1)/L in the water and 0–6.8 (± 5.2)/kg in sediment samples. The helminth egg concentrations showed seasonal variation, probably due to changes in infection levels of the populations or natural factors, such as rainfall. The informal settlements had a greater impact than treated wastewater. For every 10,000 recreational users of the rivers 19 to 58 may be infected under undisturbed conditions, increasing to 29–88 individuals when the riverbed is disturbed. The risk from agricultural use of the rivers was above the tolerable risk values applicable for wastewater reuse, recommended by the World Health Organization. This calls for a re-evaluation of the policies governing surface water quality assessment, where the inclusion of helminth eggs and sediment monitoring will be critical.

2017 ◽  
Vol 24 (1) ◽  
pp. 65-85 ◽  
Author(s):  
Anna Szymonik ◽  
Joanna Lach ◽  
Krystyna Malińska

Abstract Rapid development of pharmaceutical industry, and thus widespread availability of different types of therapeutical and increased intake of pharmaceuticals, results in elevated concentrations of pharmaceuticals in municipal wastewater subjected to treatment in wastewater treatment plants. Pharmaceuticals present in raw wastewater discharged from hospitals, households, veterinary and health care clinics eventually end up in wastewater treatment plants. Commonly applied methods for treating wastewater do not allow complete removal of these contaminants. As a consequence, pharmaceuticals still present in treated wastewater are introduced to water environment. The most frequently identified pharmaceuticals in surface water belong to the following groups: non steroidal anti inflammatory drugs, beta-blockers, estrogens and lipid regulators. The most difficult is removal of diclofenac, clofibric acid and carbamazepine as these substances show low biodegradability. Diclofenac can be removed in the process of wastewater treatment by 40%, carbamazepine by 10%, and clofibric acid from 26 to 50%. The presence of diclofenac sodium in the rivers in Poland was confirmed and the concentrations were following: 380 ng/dm3 (the Warta river), 470 ng/dm3 (the Odra river), 140 ng/dm3 (the Vistula river). Naproxene was found in the Warta river at the concentration of 100 ng/dm3. The presence of pharmaceuticals in surface water can be toxic to aqueous microorganisms and fish. Recent studies confirmed also the presence of pharmaceuticals in drinking water. This is considered as a problem especially in urban agglomerations such as Berlin or large cities in Spain and China. The studies showed that pharmaceuticals were also identified in the samples taken from the Polish rivers and drinking water. The presence of naproxene and diclofenac at the concentrations of 13 and 4 ng/dm3 was identified in drinking water sampled from water intakes in Poznan. Surface water and drinking water showed also the presence of illegal drugs.


2021 ◽  
Vol 14 (4) ◽  
pp. 80-87
Author(s):  
L. Sabliy ◽  

Wastewater generated during vegetable oil production contains various pollutants that enter it during soapstock processing: fats and fatty acids and their salts (aqueous soap solutions), glycerin, phosphoglycerates, neutral fat, phosphatides, proteins, carbohydrates, dyes, unsaponifiable and waxy substances, salts, mechanical impurities, etc. Aim. The purpose of the work was to study the processes of purification of industrial wastewater from oil production and to propose an effective technology for their treatment, taking into account the regulatory requirements for the discharge of treated wastewater into the city sewage system. Methods. Chemical oxygen demand (COD) was determined by the dichromate method. The concentration of suspended solids was determined by gravimetric method. Results. As a result of research, calcium carbonate was chosen as an alkaline reagent. After treatment of soapstock with calcium carbonate followed by flotation, the effect of removing the suspended particles was 70–75%, and COD decreased by 60%. On the basis of the research, a technology for processing soapstock was proposed, including sequential processes of physicochemical wastewater treatment —averaging, alkalization with calcium carbonate, stage I of flotation, coagulation, stage II of flotation, oxidation with hydrogen peroxide, filtration through quartz filters and adsorption on carbon filters. Conclusion. An effective technology for preliminary cleaning of the soapstocks oil production has been developed. This will significantly reduce the concentration of organic matter and other pollutants in soapstocks, which will significantly reduce the impact of such effluents on the processes of biological wastewater treatment of urban wastewater treatment plants.


2011 ◽  
Vol 64 (10) ◽  
pp. 1980-1986 ◽  
Author(s):  
R. R. Giri ◽  
H. Ozaki ◽  
T. Okada ◽  
S. Takikita ◽  
S. Taniguchi ◽  
...  

The widespread detection of perfluorinated compounds (PFCs) in the water environment has been a concern for the last several years, while effluents from wastewater treatment facilities are the major sources of these compounds. Even advanced oxidation technologies (AOTs) are not useful for mineralization of the compounds due to their very high stability. Photochemical techniques using particularly vacuum UV (VUV) have been found to be very promising in this regard. But the use of VUV in UV-based AOTs has still not progressed much. Moreover, the impact of water quality on PFCs photomineralization is unknown. This investigation aimed to assess photomineralization potentials of perfluorooctanoic acid (PFOA) in ultrapure water (UPW), tap water (TW), surface water and treated wastewater effluent using a reactor setup enabling maximum utilization of VUV emission of low pressure lamp in laboratory batch experiments. Neya River water (NRW) and the Nakahama Wastewater Treatment Plant Effluent (NWWTPE) represented surface water and treated wastewater effluent respectively. Also, tests were carried out in 50% diluted NRW and NWWTPE. PFOA photomineralization in terms of PFOA removal, defluorination and total organic carbon (TOC) removal are discussed. The usefulness of the method for PFOA mineralization in organic-rich wastewaters, and further research needs are also highlighted.


Geosciences ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 93 ◽  
Author(s):  
Pooria Ebrahimi ◽  
Maurizio Barbieri

As a result of high doses of paramagnetic gadolinium (Gd) chelates administered in magnetic resonance imaging (MRI) exams, their unmetabolized excretion, and insufficient removal in wastewater treatment plants (WWTPs), large amounts of anthropogenic Gd (Gdanth) are released into surface water. The upward trend of gadolinium-based contrast agent (Gd-CA) administrations is expected to continue growing and consequently higher and higher anthropogenic Gd concentrations are annually recorded in water resources, which can pose a great threat to aquatic organisms and human beings. In addition, the feasibility of Gd retention in patients administered with Gd-CAs repeatedly, and even potentially fatal diseases, including nephrogenic systemic fibrosis (NSF), due to trace amounts of Gd have recently arisen severe health concerns. Thus, there is a need to investigate probable adverse health effects of currently marketed Gd-CAs meticulously and to modify the actual approach in using Gd contrast media in daily practice in order to minimize unknown possible health risks. Furthermore, the employment of enhanced wastewater treatment processes that are capable of removing the stable contrast agents, and the evaluation of the ecotoxicity of Gd chelates and human exposure to these emerging contaminants through dermal and ingestion pathways deserve more attention. On the other hand, point source releases of anthropogenic Gd into the aquatic environment presents the opportunity to assess surface water—groundwater interactions and trace the fate of wastewater plume as a proxy for the potential presence of other microcontaminants associated with treated wastewater in freshwater and marine systems.


2021 ◽  
Vol 25 (2) ◽  
pp. 169-182
Author(s):  
Tony Venelinov ◽  
◽  
Galina Yotova ◽  
Veronika Mihaylova ◽  
Svetlana Lazarova ◽  
...  

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.


2020 ◽  
Vol 71 (4) ◽  
pp. 313-316
Author(s):  
Alina Roxana Banciu ◽  
Lucian Ionescu ◽  
Daniela Liliana Ionica ◽  
Monica Alexandra Vaideanu ◽  
Simona Mariana Calinescu ◽  
...  

Wastewater treatment plants are major interface between rural and urban activities and the natural environment with problems relating to the survival and transmission of the fecal bacteria into streams and rivers. The main goal of this paper was to showed the impact of WWTPs on fecal populations bacteria and their dissemination into the aquatic ecosystems. The sampling campaigns were conducted in 2019 where the hospital and WWTPs wastewater from three cities from the south-eastern part of Romania and the surface water of their emissaries were trimestral collected. The quantitative and qualitative analysis of total and fecal coliforms indicated the efficiency of wastewater treatment processes but at the same time, the contribution of contamination with hospital effluents has been demonstrated. Also, the microbiological results showed the selectivity of the destruction of fecal coliform bacteria between wastewater and surface water.


Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 221
Author(s):  
Rafał Tytus Bray ◽  
Katarzyna Jankowska ◽  
Eliza Kulbat ◽  
Aneta Łuczkiewicz ◽  
Aleksandra Sokołowska

The paper presents the results of research on the use of ultrafiltration, using membranes of 200 and 400 kDa separation, for disinfection of municipal treated wastewater. The research was conducted on a fractional technical scale using real municipal treated wastewater from two large wastewater treatment plants treating most of the wastewater over the one-million polycentric Gdańsk agglomeration (1.2 million inhabitants). UF 200 kDa and UF 400 kDa processes enabled further improvement of the physical and chemical parameters of treated wastewater. Total phosphorus (to below 0.2 mg/L–UF 200 kDa, 0.13 mg/L–UF 400 kDa) and turbid substances (to below 0.2 mg/L, both membranes) were removed in the highest degree. COD was reduced efficiently (to below 25.6 mgO2/L–UF 200 kDa, 26.8 mgO2/L–UF 400 kDa), while total nitrogen was removed to a small extent (to 7.12 mg/L–UF 200 kDa and 5.7 mg/L–UF 400 kDa. Based on the reduction of indicator bacteria; fecal coliforms including E. coli (FC) and fecal enterococci (FE) it was found that the ultrafiltration is an effective method of disinfection. Not much indicator bacterial were observed in the permeate after processes (UF 200 kDa; FC—5 CFU/L; FE—1 CFU/L and UF 400 kDa; FC—70 CFU/L; FE—10 CFU/L. However, microscopic analysis of prokaryotic cells and virus particles showed their presence after the application of both membrane types; TCN 3.0 × 102 cells/mL–UF 200 kDa, 5.0 × 103 cells/mL–UF 400 kDa, VP 1.0 × 105/mL. The presence of potentially pathogenic, highly infectious virus particles means that ultrafiltration cannot be considered a sufficient disinfection method for treated wastewater diverted for reuse or discharged from high load wastewater treatment plants to recreational areas. For full microbiological safety it would be advisable to apply an additional disinfection method (e.g., ozonation).


2021 ◽  
Vol 3 (7) ◽  
Author(s):  
T. S. C. Quintão ◽  
F. G. Silva ◽  
A. L. Pereira ◽  
W. N. Araújo ◽  
P. M. Oliveira ◽  
...  

AbstractHuman enteric viruses, such as enteric adenoviruses (HAdV), are known to be involved with gastrointestinal disorders, especially acute gastroenteritis. Several studies have used HAdV as an indicator of water quality, since they are considered highly stable and widely distributed viruses in water matrices. The aim of this study was to detect and genotype HAdVs in water matrices impacted by discharges of treated effluents from wastewater treatment plants (WWTPs). Wastewater treatment plants from the sanitary system of the Brazilian Federal District were assessed in 2018 and 2019. Samples were collected upstream and downstream from discharge points for each WWTP. Viral concentration based on adsorption-elution and conventional PCR was used for molecular detection, and positive samples were sequenced for phylogenetic analysis. Pluviosity data for the period in which the samples were collected were obtained. Our results demonstrated the presence of HAdVs in 27.2% (61/224) of the samples. The positivity was significantly higher in downstream samples compared to upstream. Moreover, the HAdV positivity was higher in downstream samples collected from receiving water bodies impacted by secondary-level WWTPs in comparison with those impacted by tertiary-level WWTPs. Phylogenetic analysis demonstrated the presence of genotypes 40 and 41, with prevalence of HAdV genotype 41. Despite the predominance of HAdV-41, an increasing frequency of the HAdV-40 was associated with higher pluviosity. In conclusion, this study is the first documentation in the Brazilian Federal District dealing with the prevalence and diversity of HAdVs in several WWTP, along with their correlation with rainfall index.


2018 ◽  
Vol 45 ◽  
pp. 00054 ◽  
Author(s):  
Bozena Mrowiec

The aim of this paper was to review the literature data regarding the physico-chemical characteristic of plastic pollutants discharged with municipal sewage, the practical possibility of removing microplastic particles from wastewater during different treatment steps in WWTPs and the problem of surface water contamination within them. Microplastics (the size range of 1 nm to < 5 mm), have been recognized as an emerging threat, as well as an ecotoxicological and ecological risk for water ecosystems. Municipal wastewater treatment plants (WWTPs) are mentioned as the main point sources of microplastics in an aquatic environment. Microplastic particles can be effectively removed in the primary treatment zones via solids skimming and sludge settling processes. Different tertiary treatment processes such as: gravity sand filtration, discfilter, air flotation and membrane filtration provide substantial additional removal of microplastics, and the efficiency of wastewater treatment process can be at a removal level of 99.9%. Nevertheless, given the large volumes of effluent constantly discharged to receivers, even tertiary level WWTPs may constitute a considerable source of microplastics in the surface water.


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