Uniform protocol for wastewater UV validation applications

2013 ◽  
Vol 8 (1) ◽  
pp. 83-94
Author(s):  
G. E. Whitby ◽  
O. Lawal ◽  
P. Ropic ◽  
S. Shima ◽  
B. Ferran ◽  
...  

The treatment objective of an ultraviolet disinfection system used in a wastewater application is to protect the aquatic environment and users of water that receive discharges from wastewater treatment plants. To ensure this objective is adequately met it is important to validate, or verify equipment performance for a specific application. The widely accepted method for completing this validation is by determining the UV dose delivery performance using biodosimetry. Until now a standard bioassay did not exist for UV equipment that is used to disinfect treated wastewater from a biological treatment plant that is achieving an average effluent quality of less than 30 mg/L BOD/TSS and disinfection requirements of 126 cfu/100 mL E. coli over a 30 day geometric mean or 200 cfu/100 mL fecal coliforms over a 30 day geometric mean. A uniform bioassay for wastewater UV equipment that can be widely adopted by industry and regulatory bodies was developed and approved by the International Ultraviolet Association. This bioassay for UV equipment is described.

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).


1994 ◽  
Vol 29 (12) ◽  
pp. 255-266 ◽  
Author(s):  
T. Gschlößl

UV-irradiation as an effective method of diminishing germs in the outlet of wastewater treatment plants was studied in a half-scale pilot-project sponsored by the State of Bavaria/BRD for a period of 3 years. Technical, physical and biological parameters capable of influencing this process were examined. The possibility to improve the hygienic and also the ecological structure of receiving waters was put to discussion. Possible effects of formed bypproducts upon the water biocoenosis of rivers were pointed out. The results demonstrated that UV-irradiation can diminish the number of germs in the outlet of a treatment plant to an extent which is sufficient to guarantee the maintenance of the bacteriological and presumably also the virological values set by the EC Bathing Water Directive. Nevertheless the UV-treatment process requires further technological development and research work concerning i.e. the improvement of hydraulic conditions, coat-forming on the quartz sleeves of the lamps, photochemical forming of by-products, after-growth and effects upon the localised benthic flora and fauna of the receiving water. It has to be stressed that a significant improvement of the bacteriological structure of flowing waters is only attainable, if the influx from non-point sources can be reduced simultaneously.


2012 ◽  
Vol 65 (4) ◽  
pp. 589-595 ◽  
Author(s):  
A. Ouali ◽  
H. Jupsin ◽  
J. L. Vasel ◽  
L. Marouani ◽  
A. Ghrabi

Korba wastewater treatment plant is a conventional activated sludge followed by three maturation ponds (MP1, MP2, MP3) in series acting as a tertiary treatment. The first study of wastewater treatment plants showed that the effluent concentration of Escherichia coli and enterococci at the outlet of the (MP3) varies between 103 and 104CFU/100 ml. After the hydrodynamic study conducted by Rhodamine WT which showed short-circuiting in the MP1, two baffles were introduced in the first maturation pond (MP1) to improve the hydrodynamic and the sanitary performances. The second hydraulic study showed that the dispersion number ‘d’ was reduced from 1.45 to 0.43 by this engineering intervention and the Peclet number was raised from 0.69 to 2.32. The hydraulic retention time was increased by 14 h. Because of well-designed baffles, the removal efficiency of E. coli and enterococci was raised between 0.2 and 0.7 log units for the first maturation pond.


2010 ◽  
Vol 61 (6) ◽  
pp. 1383-1392 ◽  
Author(s):  
A. Łuczkiewicz ◽  
S. Fudala-Książek ◽  
K. Jankowska ◽  
B. Quant ◽  
K. Olańczuk-Neyman

The occurrence of resistance patterns among wastewater fecal coliforms was determined in the study. Susceptibility of the isolates was tested against 19 antimicrobial agents: aminoglycosides, aztreonam, carbapenems, cephalosporines, β-lactam/β-lactamase inhibitors, penicillines, tetracycline, trimethoprim/sulfamethoxazole, and fluoroquinolones. Additionally the removal of resistant isolates was evaluated in the laboratory-scale wastewater treatment model plant (M-WWTP), continuously supplied with the wastewater obtained from the full-scale WWTP. Number of fecal coliforms in raw (after mechanical treatment) and treated wastewater, as well as in aerobic chamber effluent was determined using selective medium. The selected strains were identified and examined for antibiotic resistance using Phoenix Automated Microbiology System (BD Biosciences, USA). The strains were identified as Escherichia coli (n = 222), Klebsiella pneumoniae ssp. ozaenae (n = 9), and Pantoea agglomerans (n = 1). The isolate of P. agglomerans as well as 48% of E. coli isolates were sensitive to all antimicrobials tested. The most frequent resistance patterns were found for ampicillin: 100% of K. pneumoniae ssp. ozaenae and 41% of E. coli isolates. Among E. coli isolates 12% was regarded as multiple antimicrobial resistant (MAR). In the studied M-WWTP, the applied activated sludge processes reduced considerably the number of fecal coliforms, but increased the ratio of antimicrobial-resistant E. coli isolates to sensitive ones, especially among strains with MAR patterns.


Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2764
Author(s):  
Argyro Plevri ◽  
Klio Monokrousou ◽  
Christos Makropoulos ◽  
Christos Lioumis ◽  
Nikolaos Tazes ◽  
...  

Water reuse and recycling is gaining momentum as a way to improve the circularity of cities, while recognizing the central role of water within a circular economy (CE) context. However, such interventions often depend on the location of wastewater treatment plants and the treatment technologies installed in their premises, while relying on an expensive piped network to ensure that treated wastewater gets transported from the treatment plant to the point of demand. Thus, the penetration level of treated wastewater as a source of non-potable supply in dense urban environments is limited. This paper focuses on the demonstration of a sewer mining (SM) unit as a source of treated wastewater, as part of a larger and more holistic configuration that examines all three ‘streams’ associated with water in CE: water, energy and materials. The application area is the Athens Plant Nursery, in the (water stressed) city of Athens, Greece. SM technology is in fact a mobile wastewater treatment unit in containers able to extract wastewater from local sewers, treat it directly and reuse at the point of demand even in urban environments with limited space. The unit consists of a membrane bioreactor unit (MBR) and a UV disinfection unit and produces high quality reclaimed water for irrigation and also for aquifer recharge during the winter. Furthermore, a short overview of the integrated nutrient and energy recovery subsystem is presented in order to conceptualise the holistic approach and circularity of the whole configuration. The SM technology demonstrates flexibility, scalability and replicability, which are important characteristics for innovation uptake within the emerging CE context and market.


2012 ◽  
Vol 23 (3) ◽  
pp. 307-317 ◽  
Author(s):  
Daphne Heloisa de Freitas Muniz ◽  
Aline Silva Moraes ◽  
Ingrid de Souza Freire ◽  
Carlos José Domingos da Cruz ◽  
Jorge Enoch Furquim Werneck Lima ◽  
...  

INTRODUCTION: Brazil's Federal District (FD) has seen steep population growth in recent years, and this has increased demand for high-quality water. AIM: The present work aims to evaluate the quality of surface water from two water bodies in the FD at six sampling points, three of which are in the Sobradinho River (the receiving body of a sewage treatment plant effluent) and three in the Jardim River (located in an agricultural region). METHODS: Analyses were carried out every thirty days, for twelve months, covering rainy and dry seasons. Parameters were analyzed such as temperature, pH, dissolved oxygen (DO), conductivity, turbidity, total hardness, main ions, total and fecal coliforms (E. coli) in water. Ecotoxicological evaluation was also performed, using the micro-crustacean Ceriodaphnia dubia. RESULTS: Data of physical and chemical determinations showed DO, conductivity, Cl-, NO3-, SO4(2-) and Na+ to be important in indicating contamination by urban effluents. On the subject of biological parameters - E. coli and ecotoxicological evaluation - the former was seen to be more effective in the urban area. However, in the countryside, the assay with C. dubia proved to be the most sensitive, although less than ideal, because the organism is very sensitive to low water hardness. CONCLUSIONS: The fecal coliform indicator (E. coli) was the most effective one for comparing water quality in the two basins, mainly for the urbanized one, while ecotoxicity assays with C. dubia were harmed by the natural chemical composition of the water.


2016 ◽  
Vol 74 (12) ◽  
pp. 2935-2945 ◽  
Author(s):  
C. Silva ◽  
J. Saldanha Matos ◽  
M. J. Rosa

High quality services of wastewater treatment require a continuous assessment and improvement of the technical, environmental and economic performance. This paper demonstrates a comprehensive approach for benchmarking wastewater treatment plants (WWTPs), using performance indicators (PIs) and indices (PXs), in a ‘plan-do-check-act’ cycle routine driven by objectives. The performance objectives herein illustrated were to diagnose the effectiveness and energy performance of an oxidation ditch WWTP. The PI and PX results demonstrated an effective and reliable oxidation ditch (good–excellent performance), and a non-reliable UV disinfection (unsatisfactory–excellent performance) related with influent transmittance and total suspended solids. The energy performance increased with the treated wastewater volume and was unsatisfactory below 50% of plant capacity utilization. The oxidation ditch aeration performed unsatisfactorily and represented 38% of the plant energy consumption. The results allowed diagnosing opportunities for improving the energy and economic performance considering the influent flows, temperature and concentrations, and for levering the WWTP performance to acceptable–good effectiveness, reliability and energy efficiency. Regarding the plant reliability for fecal coliforms, improvement of UV lamp maintenance and optimization of the UV dose applied and microscreen recommissioning were suggested.


2006 ◽  
Vol 54 (10) ◽  
pp. 87-93 ◽  
Author(s):  
T. Hashimoto ◽  
K. Takahashi ◽  
T. Murakami

Since the natural estrogens 17 β-estradiol (E2) and estron (E1), and the synthetic estrogen 17 α-ethynyl estradiol (EE2) have strong endocrine disrupting effects and the tendency to persist in effluent from wastewater treatment plants, effective measures are needed to remove them from wastewater. In this research, to gain an understanding of the characteristics of estrogen decomposition by ozonation, experiments were conducted using effluent from an actual wastewater treatment plant. In this experiment, estrogen was added to effluent at a concentration of 200 ng/l and 20 ng/l before the ozonation experiments. The results showed 90% or more of estrogen concentration and estrogenic activity of E2, E1 and EE2 to be removed at an ozone dose of 1 mg/l. At an ozone dose of 3 mg/l, the estrogen concentration and estrogenic activity of E2, E1 and EE2 in the treated water fell below the detection limit. The removal rate was not influenced by the kind of estrogen. No generation of byproducts with estrogenic activity was observed. The authors conclude that estrogen in secondary treated wastewater can be almost entirely removed at the practical ozone dose rate applied for the purpose of disinfection, which is up to about 5 mg/l.


2018 ◽  
Author(s):  
Olayinka Osuolale ◽  
Anthony Okoh

ABSTRACTBackgroundPoorly or partially treated wastewater disposed of can contaminate water and even properly treated sewage can have its problems. The highlight of this danger is wastewater treatment plants serving as reservoir for proliferation of antibiotic resistant organisms. We have reported the state of two wastewater treatment in the Eastern Cape of South Africa which discharge poorly and partially treated effluents. Our aims to identify Vibrio spp. and their antibiotic profiles in treated final effluent discharge from wastewater treatment plant.MethodsCulture based approach using the TCBS agar for isolationVibriospp., presumptive isolates were purified and confirmed using PCR. The confirmed isolated were also genotyped to identify the species present. The antibiotic profiling of the confirmed isolates was using the CLSI recommended first line antibiotics for Vibrio.ResultsOut of the 786 presumptive isolates, 374 were confirmed asVibriospp. None of the Vibrio spp. pathotypes were present in the confirmed isolates. Randomized isolates of 100 Vibrio spp. were selected, > 90 % of the isolates were susceptible to Ciprofloxacin, and > 50 – 80 % for Ampicillin, Chloramphenicol, Tetracycline, Cefotaxime, and Trimethoprim-sulfamethoxazole respectively.ConclusionsWe are able to isolate Vibrio spp. from treated effluents but none of their pathotypes were present. The antibiotic agents considered for primary testing which are ciprofloxacin was the most effective of the antibiotic drugs, followed by cefotaxime, tetracycline with less susceptibility. Contamination from discharged effluents from wastewater treatment can lead to spread of spread of disease in this environment. The WWTPs studied are sources of pollution to surface water with environmental and public health.


2021 ◽  
Author(s):  
Semase Matseleng ◽  
Ozekeke Ogbeide ◽  
Patricks' Otomo Voua

Abstract Wastewater treatment facilities in developing countries like South Africa are major sources of contaminants via effluent into the environment, which could portend high toxicity risks for non-target flora and fauna. To this end, a study was conducted to determine the ecotoxicological responses of selected organism to treated and untreated wastewater from the wastewater treatment plants in an industrial town. The snail Helix pomatia was exposed to OECD artificial soil spiked with untreated or treated wastewater at the following concentrations: 0, 25, 50, 75, 100%. The ecotoxicological responses of Helix pomatia to wastewater were determined by assessing the biomass, survival, reproduction and biomarker responses (Catalase ‒ CAT and Acetylcholinesterase ‒ AChE activities). The overall results showed significant effects on the survival, reproduction and biomass of H. pomatia. Similar results were observed for juvenile emergence. An EC50 of 5.751% for egg production and an EC50 of 6.233% for juvenile emergence were determined in the untreated wastewater. Such indices could not be computed for the treated wastewater, indicating a decreased in toxicity between the untreated and the treated samples. For both the AChE and CAT activities, there was no statistical difference between treated and untreated wastewater treatments. The results from this study highlight the toxic effects of untreated wastewater and indicate that treated wastewater (effluent) released from the wastewater treatment plant in Phuthaditjhaba remains suitable for invertebrate fauna such as H. pomatia.


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