Removal Efficiencies of Microorganisms in Wastewater Treatment Processes

1993 ◽  
Vol 28 (7) ◽  
pp. 55-61 ◽  
Author(s):  
Tsuyoshi Hirata ◽  
Kiyoshi Kawamura ◽  
Kazuyoshi Yano ◽  
Mitsumi Kaneko ◽  
Takeo Moniwa ◽  
...  

The removal characteristics of indigenous microorganisms in wastewater treatment unit processes were studied at five operating wastewater treatment plants. The removal efficiencies of the selected microorganisms in each unit process were dependent upon not only the systems but also the kinds of microorganisms. In almost all processes, the removal efficiencies of total coliforms were similar to or higher than those of Clostridium perfringens except for filtration processes. In the additional survey, focussed on the comparison of removal efficiencies of total coliforms, Cl. perfringens and coliphages, little difference was found between CL perfringens and coliphages. From these results, it may be suggested that CL Perfringens is an effective indicator microorganism for evaluating microorganism removal in wastewater treatment processes and systems.

2010 ◽  
Vol 62 (10) ◽  
pp. 2450-2458 ◽  
Author(s):  
Angela Yu-Chen Lin ◽  
Cheng-Fan Lin ◽  
Yu-Ting Tsai ◽  
Hank Hui-Hsiang Lin ◽  
Jie Chen ◽  
...  

Pharmaceuticals and personal care products (PPCPs) constitute a class of chemicals of emerging concern due to the potential risks they pose to organisms and the environment, even at low concentrations (ng/L). Recent studies have found that PPCPs are not efficiently removed in secondary wastewater treatment plants (WWTPs). This study has: (1) simultaneously investigated the occurrence of sixty-one PPCPs using solid phase extraction and high-performance liquid chromatography-tandem mass spectrometry, (2) evaluated removal efficiencies of target PPCPs in six WWTPs that discharge effluents into major Taiwanese rivers, and lastly (3) examined matrix interference during analysis of target PPCPs in water samples. The twenty target PPCPs were chosen for their high detection frequencies, high influent concentrations, and stability during wastewater treatment processes. Caffeine and acetaminophen were detected at the highest concentrations (as high as 24,467 and 33,400 ng/L) and were effectively removed (both >96%); other PPCPs were detected in the high ng/L range but were not effectively removed. Matrix interference (by ion suppression or enhancement) during the analysis resulted in underestimation of the removal efficiencies of erythromycin-H2O, cefazolin, clarithromycin, ibuprofen, diclofenac, clofibric acid and gemfibrozil.


Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 720 ◽  
Author(s):  
Jin-Pil Kim ◽  
Dal Rae Jin ◽  
Wonseok Lee ◽  
Minhee Chae ◽  
Junwon Park

In this study, livestock wastewater treatment plants in South Korea were monitored to determine the characteristics of influent and effluent wastewater, containing four types of veterinary antibiotics (sulfamethazine, sulfathiazole, chlortetracycline, oxytetracycline), and the removal efficiencies of different treatment processes. Chlortetracycline had the highest average influent concentration (483.7 μg/L), followed by sulfamethazine (251.2 μg/L), sulfathiazole (230.8 μg/L) and oxytetracycline (25.7 μg/L), at five livestock wastewater treatment plants. Sulfathiazole had the highest average effluent concentration (28.2 μg/L), followed by sulfamethazine (20.8 μg/L) and chlortetracycline (11.5 μg/L), while no oxytetracycline was detected. For veterinary antibiotics in the wastewater, a removal efficiency of at least 90% was observed with five types of treatment processes, including a bio-ceramic sequencing batch reactor, liquid-phase flotation, membrane bioreactor, bioreactor plus ultrafiltration (BIOSUF) and bio best bacillus systems. Moreover, this study evaluated the removal efficiency via laboratory-scale experiments on the conventional contaminants, such as organic matter, nitrogen, phosphorus and veterinary antibiotics. This was done using the hydraulic retention time (HRT), under three temporal conditions (14 h, 18 h, 27 h), using the anaerobic–anoxic–oxic (A2O) process, in an attempt to assess the combined livestock wastewater treatment process where the livestock wastewater is treated until certain levels of water quality are achieved, and then the effluent is discharged to nearby sewage treatment plants for further treatment. The removal efficiencies of veterinary antibiotics, especially oxytetracycline and chlortetracycline, were 86.5–88.8% and 87.9–90.8%, respectively, exhibiting no significant differences under various HRT conditions. The removal efficiency of sulfamethazine was at least 20% higher at HRT = 27 h than at HRT = 14 h, indicating that sulfamethazine was efficiently removed in the A2O process with increased HRT. This study is expected to promote a comprehensive understanding of the behavior and removal of veterinary antibiotics in the livestock wastewater treatment plants of South Korea.


2018 ◽  
Vol 53 (4) ◽  
pp. 167-180 ◽  
Author(s):  
Meera Shanmuganathan ◽  
Zifeng Zhang ◽  
Ed Sverko ◽  
Rachel Brymer ◽  
Biban Gill ◽  
...  

Abstract An investigation of brominated flame retardants (BFRs), polybrominated diphenylethers (PBDEs), and chlorinated flame retardants was conducted in samples from Canadian wastewater treatment plants (WWTPs). The penta-BDE mixture and deca-BDE were most commonly detected. Median removal efficiencies of PBDEs by WWTPs were 71% to 99% and higher concentrations of PBDEs were found in influent samples in summer, compared to winter. Three novel brominated flame retardants (nBFRs) including 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTeBB or TBB), and bis(2-ethyl-1-hexyl)tetrabromophthalate (BEHTBP or TBPH) were detected in greater than 80% of influents and biosolids. Median removal efficiencies were 45% to 99% for BTBPE, 63% to 99% for TBB, and 88% to 99% for TBPH. Detection of total dechlorane plus ((DP) syn and anti) was greater than 90% in both wastewater and biosolids samples. However, median removal efficiencies were between 51% and 66% for total DP. Overall, PBDEs were effectively removed via different treatment processes, while BTBPE, TBB, and DP exhibited lower removal rates, which could be due to their physical chemical properties.


2020 ◽  
Author(s):  
Namita Maharjan ◽  
Choolaka Hewawasam ◽  
Masashi Hatamoto ◽  
Takashi Yamaguchi ◽  
Hideki Harada ◽  
...  

Need of self-sustaining wastewater treatment plants (WWTPs) has become critical to cope up with dynamics of the environmental regulations and rapid advancements in the contemporary technologies. At present there are limited number of self-sustaining WWTPs around the world. The aim of this chapter is to present state -of- art of Downflow Hanging Sponge (DHS) system which was developed as a post treatment unit of Upflow Anaerobic Sludge Blanket (UASB) from sustainability perspective. DHS system is a non-submerged fixed bed trickling filter (TF) that employs a core technology of polyurethane sponges as a media where the microorganisms thrive and major treatment processes take place. This chapter reviews the introduction of DHS system (UASB+DHS) summarizes the quantitative analysis of environmental, economic and social sustainability using indicators. Furthermore, self-sustaining prospects of DHS system are assessed and discussed by comparing with conventional TF (UASB+TF).


2021 ◽  
Vol 11 (16) ◽  
pp. 7388
Author(s):  
Sofia Silva ◽  
Vitor Vale Cardoso ◽  
Lúcia Duarte ◽  
Rui Neves Carneiro ◽  
Cristina Maria Martins Almeida

Due to the high consumption and incorrect disposal of pharmaceutical active compounds (PhACs), they are recognized as contaminants of emerging concern. Wastewater treatment plants (WWTPs) may be inefficient in removing PhACs, therefore discharging them into surface waters. The removal efficiencies of five WWTPs located in the south of Portugal (Alentejo) were evaluated in 2020. Twenty-six PhACs were analyzed in wastewater influents, effluents, and surface waters, upstream and downstream of the WWTPs by solid-phase extraction (SPE) and ultra-performance liquid chromatography coupled with tandem mass detection (UPLC–MS/MS). The most representative PhACs in influents were acetaminophen, caffeine, naproxen, ibuprofen, and diclofenac with minimum-maximum concentrations of 49–225 µg/L, 26–46 µg/L, 5.9–13 µg/L, 5.2–22 µg/L, and 1.3–2.5 µg/L, respectively. For effluents, it was acetaminophen, caffeine, and diclofenac with minimum-maximum concentrations of 0.054–7.8 µg/L, 0.084–4.8 µg/L, and 0.28–3.3 µg/L, respectively. The highest removal efficiencies were observed for acetaminophen, sulfadiazine, cortisone, testosterone, metoprolol, and propranolol (100%). The lowest removal efficiencies were observed for carbamazepine (2.7%) and diclofenac (−13.2%). The risk quotient of sulfamethoxazole and diclofenac were higher than 1 for receiving waters, indicating they probably pose high risks to aquatic organisms.


1982 ◽  
Vol 14 (1-2) ◽  
pp. 121-133
Author(s):  
C Forsberg ◽  
B Hawerman ◽  
B Hultman

Experience from advanced municipal wastewater treatment plants and recovery of polluted waters are described for the last ten years in Sweden. Except in municipalities with large recipients, the urban population is served by treatment plants with combined biological and chemical treatment. Most of these plants are post-precipitation plants. Several modified operational modes have been developed in order to improve the removal efficiencies of pollutants and to reduce the costs. Results are presented on the recovery of specially investigated lakes with a lowered supply of total phosphorus and organic matter.


Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 798
Author(s):  
Samendra P. Sherchan ◽  
Shalina Shahin ◽  
Jeenal Patel ◽  
Lauren M. Ward ◽  
Sarmila Tandukar ◽  
...  

In this study, we investigated the occurrence of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) RNA in primary influent (n = 42), secondary effluent (n = 24) and tertiary treated effluent (n = 34) collected from six wastewater treatment plants (WWTPs A–F) in Virginia (WWTP A), Florida (WWTPs B, C, and D), and Georgia (WWTPs E and F) in the United States during April–July 2020. Of the 100 wastewater samples analyzed, eight (19%) untreated wastewater samples collected from the primary influents contained SARS-CoV-2 RNA as measured by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) assays. SARS-CoV-2 RNA were detected in influent wastewater samples collected from WWTP A (Virginia), WWTPs E and F (Georgia) and WWTP D (Florida). Secondary and tertiary effluent samples were not positive for SARS-CoV-2 RNA indicating the treatment processes in these WWTPs potentially removed SARS-CoV-2 RNA during the secondary and tertiary treatment processes. However, further studies are needed to understand the log removal values (LRVs) and transmission risks of SARS-CoV-2 RNA through analyzing wastewater samples from a wider range of WWTPs.


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