UV-disinfection of treated wastewater: possible effects on surface waters

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.

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.


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.


2011 ◽  
Vol 1 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Sami M. Hamdan ◽  
Abdelmajid Nassar ◽  
Uwe Troeger

The Gaza Strip suffers from high pressure imposed on its water resources. There is a deficit of about 50 mm3 every year, which has led to a declination of groundwater level and deterioration of groundwater quality. New water resources are sought to fulfil the water deficit; among them is the artificial recharge of treated wastewater to groundwater. The impact of recharging partially treated wastewater in Gaza was tested through a pilot project implemented east of the existing wastewater treatment plant. The daily application of about 10,000 m3 of effluent to infiltration basins had an effect on the aquifer, which was monitored through the surrounding operating water wells over five years from 2000 until 2005. Although the monitored wells are operated for irrigation by farmers, impacts were clearly noticed. Groundwater levels improved and an increase in some areas of 0.6 m within three years was observed. The nitrate ion concentration also decreased in the groundwater due to nitrification processes. However, chloride ion, which indicates salinity, increased because the effluent has high chloride concentration. Boron levels increased in some areas to 0.5 mg/l, which could affect sensitive crops grown in the area.


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.


2001 ◽  
Vol 44 (2-3) ◽  
pp. 111-117 ◽  
Author(s):  
J. Stemplewski ◽  
A. Schulz ◽  
J. Schön

In the following paper the technique of benchmarking was transferred to the field of wastewater treatment. The method was developed within a pilot project, in which 4 wastewater treatment plants (WWTP) (size category: 10,000-100,000 p. e.) of the Emschergenossenschaft/Lippeverband and the Aggerverband were involved. Meanwhile this method is applied to more than 100 WWTP. Specific technical and economic parameters were determined for the whole treatment plant and afterwards assigned to the different treatment steps. With these numbers differences between the examined plants and the respective benchmarks were visible. On the basis of the following cause analysis a schedule could be developed containing at first measures, which could be translated into action immediately. The less obvious reasons for differences between individual numbers required a deeper cause analysis. Because of external influences not all the plants can reach the benchmarks.


2021 ◽  
Author(s):  
Yan Li ◽  
Ethan Wood ◽  
Gergely Kosa ◽  
Bushra Muzamil ◽  
Christian Vogelsang ◽  
...  

Abstract This study demonstrated that the application of filamentous co-culture could be a promising supplementary approach to further purify municipal tertiary wastewater in Nordic country. Initial screening of 25 algae strains across multiple genera revealed that Spirogyra sp. and Klebsormidium sp. were suitable for use as a coculture for phycoremediation of the tertiary effluent from a wastewater treatment plant, and this result was validated in three consecutive outdoor pilot tests at 10–15 oC. In the first two batches of pilot tests, the total prosperous and ammonium were depleted close to zero in 24 hours, while the pH in the wastewater increased from 7 to 9. In the 3rd batch, CO2 was thereby added for pH control. Macronutrients (N and P) were successfully removed from the treated wastewater. The total algae biomass increased 2 to 3 times over 7 days with average algae productivity of 1.68 g m2 d− 1. Meanwhile, the produced algae biomass accumulated notable mineral elements (Ca, Mg, K, Fe and Al) and some heavy metals at levels of g kg− 1 and mg kg− 1, respectively. In light of circular economy concept, the produced biomass could be used for different valorizations based on the analytical analysis. This study provides a new insight of phycoremediation for further purification of municipal treated wastewater, by effectively using filamentous algae coculture. Given a great potential for further optimization and improvement, this proof of concept will benefit to the green transition of wastewater treatment plants in Nordic country.


2012 ◽  
Vol 78 (18) ◽  
pp. 6643-6646 ◽  
Author(s):  
Vincenza Romano ◽  
Vincenzo Pasquale ◽  
Karel Krovacek ◽  
Federica Mauri ◽  
Antonella Demarta ◽  
...  

ABSTRACTThe occurrence ofClostridium difficilein nine wastewater treatment plants in the Ticino Canton (southern Switzerland) was investigated. The samples were collected from raw sewage influents and from treated effluents. Forty-seven out of 55 characterizedC. difficilestrains belonged to 13 different reference PCR ribotypes (009, 010, 014, 015, 039, 052, 053, 066, 070, 078, 101, 106, and 117), whereas 8 strains did not match any of those available in our libraries. The most frequently isolated ribotype (40%) was 078, isolated from six wastewater treatment plants, whereas ribotype 066, a toxigenic emerging ribotype isolated from patients admitted to hospitals in Europe and Switzerland, was isolated from the outgoing effluent of one plant. The majority of the isolates (85%) were toxigenic. Forty-nine percent of them produced toxin A, toxin B, and the binary toxin (toxigenic profile A+B+CDT+), whereas 51% showed the profile A+B+CDT−. Interestingly, eight ribotypes (010, 014, 015, 039, 066, 078, 101, and 106) were among the riboprofiles isolated from symptomatic patients admitted to the hospitals of the Ticino Canton in 2010. Despite the limitation of sampling, this study highlights that toxigenic ribotypes ofC. difficileinvolved in human infections may occur in both incoming and outgoing biological wastewater treatment plants. Such a finding raises concern about the possible contamination of water bodies that receive wastewater treatment plant effluents and about the safe reuse of treated wastewater.


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.


2004 ◽  
Vol 50 (5) ◽  
pp. 29-36 ◽  
Author(s):  
M. Clara ◽  
B. Strenn ◽  
M. Ausserleitner ◽  
N. Kreuzinger

Micropollutants as pharmaceutical active compounds (PhACs), residuals of personal care products or endocrine disrupting chemicals are of increasing interest in water pollution control. In this context the removal efficiencies of sewage treatment plants (STPs) are of importance, as their effluents are important point sources for the release of those substances into the aquatic environment. Activated sludge based wastewater treatment is the worldwide prevalently used treatment technique. In conventional plants the separation of treated wastewater and sludge occurs via sedimentation. A new development is the application of membrane technology for this separation step. The studies focus on the influence of the solids retention time (SRT) on the removal efficiency, as the SRT is the most important parameter in the design of STPs. A conventional activated sludge plant (CASP) and a membrane bioreactor (MBR) were operated at different SRTs. The substances selected are the antiepileptic carbamazepine, the analgesics diclofenac and ibuprofen, the lipid regulator bezafibrate, the polycyclic musks tonalide and galaxolide and the contraceptive 17α-ethinylestradiole. No significant differences in the removal efficiency were detected. Due to the absence of suspended solids in the MBR effluent, substances with high adsorption potential could be retained to slightly higher amounts.


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