A mass balance approach to the fate of viruses in a municipal wastewater treatment plant during summer and winter seasons

2013 ◽  
Vol 69 (2) ◽  
pp. 364-370 ◽  
Author(s):  
Katharina Ulbricht ◽  
Hans-Christoph Selinka ◽  
Stefanie Wolter ◽  
Karl-Heinz Rosenwinkel ◽  
Regina Nogueira
Keyword(s):  
Wastewater Treatment ◽  
Mass Balance ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Winter Season ◽  
Treatment Plant ◽  
P Value ◽  
Virus Inactivation ◽  
Virus Removal ◽  
Virus Retention

In contrast to previous discussion on general virus removal efficiency and identifying surrogates for human pathogenic viruses, this study focuses on virus retention within each step of a wastewater treatment plant (WWTP). Additionally, the influence of weather conditions on virus removal was addressed. To account for the virus retention, this study describes a mass balance of somatic coliphages (bacterial viruses) in a municipal WWTP, performed in the winter and summer seasons of 2011. In the winter season, the concentration of coliphages entering the WWTP was about 1 log lower than in summer. The mass balance in winter revealed a virus inactivation of 85.12 ± 13.97%. During the summer season, virus inactivation was significantly higher (95.25 ± 3.69%, p-value <0.05), most likely due to additional virus removal in the secondary clarifier by insolation. Thus, a total removal of coliphages of about 2.78 log units was obtained in summer compared to 1.95 log units in winter. Rainfall events did not statistically correlate with the concentrations of coliphages entering the WWTP in summer.

Water quality in a surface-flow constructed treatment wetland polishing tertiary effluent from a municipal wastewater treatment plant

2012 ◽  
Vol 66 (9) ◽  
pp. 1977-1983 ◽  
Author(s):  
Marc W. Beutel
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Surface Flow ◽  
P Value ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plant ◽  
Energy Balance Approach

Constructed treatment wetlands (CTWs) are unique ecotechnologies that can sustainably treat a range of wastewaters. This study focused on a 0.23 ha vegetated surface-flow CTW polishing nitrate-rich (3–6 mg-N/L) tertiary effluent from a municipal wastewater treatment plant. Water quality was monitored longitudinally in the fall of 2009 and 2010. The CTW cooled water by from around 20 °C to <15 °C in both years. Longitudinal temperature profiles were successfully modeled using an energy balance approach (2009 R2 = 0.69; 2010 R2 = 0.92). The magnitude of key model fitting parameters, including albedo (0.1–0.2) and convective transfer coefficient (0.1–0.9 MJ/m2 d °C), were within ranges reported in the literature. In both years, dissolved oxygen decreased through the wetland from 6–7 mg/L to 3–4 mg/L, yielding an oxygen mass consumption rate of 0.08–0.09 g/m2 d. Longitudinal nitrate profiles were well represented by the P-k-C* model (2009 R2 = 0.88; 2010 R2 = 0.92). First order removal rates were 20.2 m/yr in 2009 and 29.0 m/yr in 2010 at a P value of 6.0. Levels of ammonia and total phosphorus increased negligibly through the wetland, remaining below 0.25 mg/L. This study shows that vegetated surface-flow CTWs are well suited to cool and polish low-BOD nitrate-dominated tertiary effluents with little degradation of other water quality parameters of concern, including phosphorus and ammonia.

scholarly journals Assessment of Microplastics in a Municipal Wastewater Treatment Plant with Tertiary Treatment: Removal Efficiencies and Loading per Day into the Environment

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1339
Author(s):  
Javier Bayo ◽  
Sonia Olmos ◽  
Joaquín López-Castellanos
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Treatment Plant ◽  
Source Control ◽  
Municipal Wastewater Treatment ◽  
Tertiary Treatment ◽  
Stable Performance ◽  
Wastewater Samples

This study investigates the removal of microplastics from wastewater in an urban wastewater treatment plant located in Southeast Spain, including an oxidation ditch, rapid sand filtration, and ultraviolet disinfection. A total of 146.73 L of wastewater samples from influent and effluent were processed, following a density separation methodology, visual classification under a stereomicroscope, and FTIR analysis for polymer identification. Microplastics proved to be 72.41% of total microparticles collected, with a global removal rate of 64.26% after the tertiary treatment and within the average retention for European WWTPs. Three different shapes were identified: i.e., microfiber (79.65%), film (11.26%), and fragment (9.09%), without the identification of microbeads despite the proximity to a plastic compounding factory. Fibers were less efficiently removed (56.16%) than particulate microplastics (90.03%), suggesting that tertiary treatments clearly discriminate between forms, and reporting a daily emission of 1.6 × 107 microplastics to the environment. Year variability in microplastic burden was cushioned at the effluent, reporting a stable performance of the sewage plant. Eight different polymer families were identified, LDPE film being the most abundant form, with 10 different colors and sizes mainly between 1–2 mm. Future efforts should be dedicated to source control, plastic waste management, improvement of legislation, and specific microplastic-targeted treatment units, especially for microfiber removal.

scholarly journals Energy Valorisation of Wastewater Treatment Plant Sludge through Thermal Gasification: An Economic Perspective

Proceedings ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 3
Author(s):  
Luis F. Carmo-Calado ◽  
Roberta Mota-Panizio ◽  
Gonçalo Lourinho ◽  
Octávio Alves ◽  
I. Gato ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Electricity Production ◽  
Baseline Scenario ◽  
Municipal Wastewater Treatment ◽  
Plant Processing ◽  
Sludge Drying ◽  
Calorific Power

The technical-economic analysis was carried out for the production of sludge-derived fuel from a municipal wastewater treatment plant (WWTP). The baseline for the analysis consists of a sludge drying plant, processing 6 m3 of sludge per day and producing a total of about 1 m3 of combustible material with 8% of moisture and a higher calorific power of 18.702 MJ/kg. The transformation of biofuel into energy translates into an electricity production of about 108 kW per 100 kg of sludge. The project in the baseline scenario demonstrated feasibility with a payback time of about six years.

Impact of a wastewater treatment plant on Cryptosporidium oocysts and Giardia cysts occurring in a surface water

2000 ◽  
Vol 41 (7) ◽  
pp. 31-37 ◽  
Author(s):  
E. Carraro ◽  
E. Fea ◽  
S. Salva ◽  
G. Gilli
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Mean Values ◽  
Cryptosporidium Oocysts ◽  
The Impact ◽  
Receiving Water ◽  
Giardia Cysts

The aim of this study was to assess the impact of a municipal wastewater treatment plant (MWTP) on the occurrence of Cryptosporidium oocysts and Giardia cysts in the receiving water. All MWTP effluent samples were Giardia and Cryptosporidium contaminated, although low mean values were found for both parasites (0.21±0.06 oocysts/L; 1.39±0.51 cysts/L). Otherwise, in the raw sewage a greater concentration was detected (4.5±0.3 oocysts/L; 53.6±6.8 cysts/L). The major occurrence of Giardia over Cryptosporidium, both in the influent and in the effluent of the MWTP, is probably related to the human sewage contribution to the wastewater. Data on protozoa contamination of the receiving water body demonstrated similar concentrations in the samples collected before (0.21±0.07 oocysts/L; 1.31±0.38 cysts/L) and after (0.17±0.09 oocysts/L and 1.01±1.05 cysts/L) the plant effluent discharge. The results of this study suggest that the MWTP has no impact related to Giardia and Cryptosporidium river water contamination, and underline the need for investigation into the effectiveness of these protozoa removal by less technologically advanced MWTPs which are the most widespread and could probably show a lower ability to reduce protozoa.

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