Study of impacts of treated wastewater to the Krka river, Slovenia

2001 ◽  
Vol 44 (6) ◽  
pp. 47-54 ◽  
Author(s):  
M. Cotman ◽  
J. Zagorc-Koncan ◽  
A. Droic

Surface waters are used for disposal of treated effluents from wastewater treatment plants. These effluents usually contain only small amounts of various contaminants but these harmful components accumulate over time in the river, especially in sediments. An integrated approach for the evaluation of the impact of treated effluents was used to predict an ecological risk assessment to the Krka river beside Novo Mesto. The effluents from pharmaceutical and municipal wastewater treatment plants were discharged too closely into the receiving stream, so that separate impacts could not be distinguished. Biologically treated industrial effluents contained great amounts of barely biodegradable organic pollution, organic nitrogen, ammonia and phosphorus, and sometimes zinc. The toxicity of effluents was mostly dependent on their chemical composition. The municipal discharge contained greater amounts of organic pollution that was completely biodegraded but still had a great nutrient pollution load. The effluents were nontoxic. The harmful substances from the effluents were traced in the river. In the downstream site slightly higher concentration of organic pollutants, organic nitrogen, phosphorus, and zinc were detected due to discharges. The river water was over-saturated with oxygen, especially in the summer. In toxicity tests, samples of the river water were nontoxic. Sediments at the downstream site accumulated from discharged organic nitrogen, phosphorus, or zinc. The results of our study show that the main problem is eutrophication of the river Krka, so it is obvious we must reduce the quantity of nutrients in the effluents from wastewater treatment plants. In both effluents it will be necessary to reduce the polluting load of phosphorus, the limiting element for growth of algae and macrophytes in the receiving stream. In the industrial effluent it will be necessary to reduce substances which cause toxicity, such as zinc and nonbiodegradable organic compounds that may be accumulated in the water ecosystem over time.

1992 ◽  
Vol 25 (4-5) ◽  
pp. 67-73
Author(s):  
H. Fleckseder ◽  
L. Prendl ◽  
H. Meulenbroek

The primary driving force for re-investments in wastewater treatment plants in Austria - and also other countries in Central Europe - is at present not an increase in load to treatment but a marked increase in effluent requirements to be fulfilled. (The re-investments necessary for sludge handling and treatment remain outside this paper.) Within a period of 20 years, the load specific requirements on aeration tank volume rose five- to tenfold, when Lv = 2.0 kg BOD5/(m3d) was the starting value, and roughly doubled for final clarifiers. In addition, the importance of the application and expansion of primary sedimentation decreased as well. This development over time in Central European countries as well as the need to utilize previous investments as long as possible - 35 to 60 years for civil works are common as periods of depreciation - indicate that investments in new plant at any location in the world have to consider the possible whole life cycle of a plant and that plant hydraulics becomes the “key hook” for expandability.


2019 ◽  
Vol 80 (12) ◽  
pp. 2352-2361
Author(s):  
L. M. L. Silva ◽  
A. F. Santiago ◽  
G. A. Silva ◽  
A. L. P. Castro ◽  
L. S. Bastos ◽  
...  

Abstract The use of light-emitting diode (LED)-illuminated photobioreactors with microalgae has been extensively studied for wastewater treatment. Most studies have used isolated microalgae species; however, this practice does not match the reality of conditions in wastewater treatment plants. Operational conditions that promote greater growth of algal biomass and that remove pollutants most effectively are disputed in the literature. In this context, LED-illuminated photobioreactors with microalgae were evaluated using multivariate analysis in order to optimize removal of pollutants (nitrogen, phosphorus, and carbonaceous organic matter). Three variables were evaluated: operating time, LED wavelength, and luminous flux intensity. A microalgae consortium was used in the photobioreactor. In addition to the LED-illuminated photobioreactors, control photobioreactors illuminated by sunlight were also operated. Using the results obtained in the optimization, a scaled-up reactor approximately 8.5 times larger in volume was operated to evaluate if the behavior would be maintained. The best operational conditions for the removal of pollutants were observed in LED-illuminated photobioreactors operated under a light intensity of 700 μmol·m−2s−1 for 15 days. Under these conditions, it was possible to remove 89.97% of carbonaceous organic matter, 86.50% of nitrogen, and 30.64% of phosphorus. The scaled-up photobioreactor operated with similar performance.


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.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7455 ◽  
Author(s):  
Imrose Kauser ◽  
Mark Ciesielski ◽  
Rachel S. Poretsky

Background In the United States, an estimated 14,748 wastewater treatment plants (WWTPs) provide wastewater collection, treatment, and disposal service to more than 230 million people. The quality of treated wastewater is often assessed by the presence or absence of fecal indicator bacteria. UV disinfection of wastewater is a common final treatment step used by many wastewater treatment plants in order to reduce fecal coliform bacteria and other pathogens; however, its potential impacts on the total effluent bacterial community are seemingly varied. This is especially important given that urban WWTPs typically return treated effluent to coastal and riverine environments and thus are a major source of microorganisms, genes, and chemical compounds to these systems. Following rainfall, stormflow conditions can result in substantial increases to effluent flow into combined systems. Methods Here, we conducted a lab-scale UV disinfection on WWTP effluent using UV dosage of 100 mJ/cm2 and monitored the active microbiome in UV-treated effluent and untreated effluent over the course of 48 h post-exposure using 16S rRNA sequencing. In addition, we simulated stormflow conditions with effluent UV-treated and untreated effluent additions to river water and compared the microbial communities to those in baseflow river water. We also tracked the functional profiles of genes involved in tetracycline resistance (tetW) and nitrification (amoA) in these microcosms using RT-qPCR. Results We showed that while some organisms, such as members of the Bacteroidetes, are inhibited by UV disinfection and overall diversity of the microbial community decreases following treatment, many organisms not only survive, but remain active. These include common WWTP-derived organisms such as Comamonadaceae and Pseudomonas. When combined with river water to mimic stormflow conditions, these organisms can persist in the environment and potentially enhance microbial functions such as nitrification and antibiotic resistance.


2003 ◽  
Vol 48 (8) ◽  
pp. 27-34 ◽  
Author(s):  
T.-K. Chen ◽  
C.-H. Ni ◽  
J.-N. Chen

Development and application of biological nutrient removal processes accelerated significantly over the past decade due to more stringent nutrients (nitrogen and phosphorus) discharge limits being imposed on wastewater treatment plants. The opto-electronic industry has developed very fast over the past decade in the world. The wastewater often contains a significant quantity of organic nitrogen compounds and has a ratio of over 95% in organic nitrogen (Org-N) to total nitrogen (T-N). In this study, a 2-stage Anoxic/Aerobic pre-denitrification process was established and the efficiency of wastewater treatment was evaluated. Wastewater from an actual LCD-plant was obtained as the sample for looking into the feasibility of opto-electronic industrial wastewater treatment. Hydraulic retention time (HRT) and mixed liquor recycle rate (MLR) were controlled independently to distinguish between the effects of these two factors. Under suitable HRT and mixed liquor recycle ratio, effluents of NH4-N, NOx-N and COD can fall below 20 mg/l, 30 mg/l and 80 mg/l.


2003 ◽  
Vol 47 (9) ◽  
pp. 71-76 ◽  
Author(s):  
A. Takahashi ◽  
T. Higashitani ◽  
Y. Yakou ◽  
M. Saitou ◽  
H. Tamamoto ◽  
...  

There are two major routes through which fish are exposed to endocrine disruptors (EDs); one route is through water that is a habitat; the other is through aquatic food such as algae and benthos. Few studies on the bioaccumulation of EDs in food have been conducted. Therefore, we evaluated the concentration in food of nonylphenol (NP), bisphenol A (BPA) and 17β-estradiol (E2), which were frequently detected in river water and in final discharge of Wastewater Treatment Plants (WWTPs) in Japan. We also evaluated the estrogenicity of samples using recombinant yeast. NP concentrations ranged 0.1-0.4 mg/L in the river water, while they ranged 8-130 mg/kg-wet in the periphytons and 8-140 μg/kg-wet in the benthos. BPA concentrations ranged 0.02-0.15 μg/L in the river water, while they ranged 2-8.8 μg/kg-wet in the periphytons and 0.3-12 μg/kg-wet in the benthos. E2 concentrations ranged 0.0001-0.0076 μg/L in the water, while they ranged 0.09-2.26 μg/kg-wet in the periphytons and <0.01-0.22 μg/kg-wet in the benthos. The estrogenicity ranged 0.0001-0.0464 μg-E2equivalent/L in the water, while it ranged 3.4-66.8 μg-E2equivalent/kg-wet in the periphytons and 7.4-5458 μg-E2equivalent/kg-wet in the benthos. Bioaccumulation factors of NP are estimated as 160-650 for the periphytons, and 63-990 for the benthos, respectively. Bioaccumulation factors of BPA are estimated as 18-650 for the periphytons, and 8-170 for the benthos, respectively. Bioaccumulation factors of E2 are estimated as 64-1,200 for the periphytons, and 100-160 for the benthos, respectively. The ratios of the periphytons and the benthos to the water in terms of the estrogenicity were larger than those in terms of the chemicals. In particularly, the ratio of the benthos to the water is about 106 in the maximum. The results suggest that food may be a more important route for fish exposed to EDs in water environment.


2013 ◽  
Vol 47 (9) ◽  
pp. 3201-3210 ◽  
Author(s):  
Halis Simsek ◽  
Murthy Kasi ◽  
Jae-Bom Ohm ◽  
Mark Blonigen ◽  
Eakalak Khan

Sign in / Sign up

Export Citation Format

Share Document