Sustainability of municipal wastewater treatment

1997 ◽  
Vol 35 (10) ◽  
pp. 221-228 ◽  
Author(s):  
P. J. Roeleveld ◽  
A. Klapwijk ◽  
P. G. Eggels ◽  
W. H. Rulkens ◽  
W. van Starkenburg

In this study the insustainability of the treatment of municipal wastewater is evaluated with the LCA-methodology. Life-Cycle Assessments (LCA) analyze and assess the environmental profile over the entire life cycle of a product or process. The LCA-methodology proved to be a proper instrument to evaluate the wastewater treatment plant on the sustainability. However, environmental impacts which are caused by sludge handling should still be classified. Besides that, the LCA should be carried out on regional level instead of on national level. In a situation of high nutrient removal the contribution of the treatment of municipal wastewater to the total insustainability level in the Netherlands is relatively low. When the sustainability of the WWTP has to be improved, the most attention has to be paid to the minimization of discharge from pollutions with the effluent and minimization of the sludge production. Because the contribution of energy consumption is relatively low, less attention can be paid to the minimization of the energy demand. The building of a WWTP and the use of chemicals are not determining the insustainability of the WWTP.

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 421
Author(s):  
Dimitra C. Banti ◽  
Michail Tsangas ◽  
Petros Samaras ◽  
Antonis Zorpas

Membrane bioreactor (MBR) systems are connected to several advantages compared to the conventional activated sludge (CAS) units. This work aims to the examination of the life cycle environmental impact of an MBR against a CAS unit when treating municipal wastewater with similar influent loading (BOD = 400 mg/L) and giving similar high-quality effluent (BOD < 5 mg/L). The MBR unit contained a denitrification, an aeration and a membrane tank, whereas the CAS unit included an equalization, a denitrification, a nitrification, a sedimentation, a mixing, a flocculation tank and a drum filter. Several impact categories factors were calculated by implementing the Life Cycle Assessment (LCA) methodology, including acidification potential, eutrophication potential, global warming potential (GWP), ozone depletion potential and photochemical ozone creation potential of the plants throughout their life cycle. Real data from two wastewater treatment plants were used. The research focused on two parameters which constitute the main differences between the two treatment plants: The excess sludge removal life cycle contribution—where GWPMBR = 0.50 kg CO2-eq*FU−1 and GWPCAS = 2.67 kg CO2-eq*FU−1 without sludge removal—and the wastewater treatment plant life cycle contribution—where GWPMBR = 0.002 kg CO2-eq*FU−1 and GWPCAS = 0.14 kg CO2-eq*FU−1 without land area contribution. Finally, in all the examined cases the environmental superiority of the MBR process was found.


2004 ◽  
Vol 50 (7) ◽  
pp. 163-169 ◽  
Author(s):  
S.J. Kang ◽  
T.A. Allbaugh ◽  
J.W. Reynhout ◽  
T.L. Erickson ◽  
K.P. Olmstead ◽  
...  

As part of an expansion to an average flow of 45.9 million gallons per day (174 mld), the Ypsilanti Community Utilities Authority wastewater treatment plant in the State of Michigan, USA, elected to install ultraviolet disinfection as a replacement for the existing chlorination process. This paper presents a unique methodology used in selecting the best system based on not only the life cycle costs, and O & M considerations but also the participation of the stakeholders. The Team members consisted of representatives of all departments at the Authority, and these Team members made the decision. The Team evaluated all criteria in the office, which was followed by verification at selected sites with similar types of equipment. The selected equipment then was pilot tested for validation of the dose-kill relationship under normal operation and also under reduced irradiation conditions. A low-pressure, high intensity system was selected, based on life-cycle cost, reliability, safety, and ease of operation. This paper describes the unique methodologies used in making that decision. The full-scale system is scheduled for start-up in Spring 2003.


2015 ◽  
Vol 73 (3) ◽  
pp. 588-596 ◽  
Author(s):  
D. Lensch ◽  
C. Schaum ◽  
P. Cornel

Many digesters in Germany are not operated at full capacity; this offers the opportunity for co-digestion. Within this research the potentials and limits of a flexible and adapted sludge treatment are examined with a focus on the digestion process with added food waste as co-substrate. In parallel, energy data from a municipal wastewater treatment plant (WWTP) are analysed and lab-scale semi-continuous and batch digestion tests are conducted. Within the digestion tests, the ratio of sewage sludge to co-substrate was varied. The final methane yields show the high potential of food waste: the higher the amount of food waste the higher the final yield. However, the conversion rates directly after charging demonstrate better results by charging 10% food waste instead of 20%. Finally, these results are merged with the energy data from the WWTP. As an illustration, the load required to cover base loads as well as peak loads for typical daily variations of the plant's energy demand are calculated. It was found that 735 m³ raw sludge and 73 m³ of a mixture of raw sludge and food waste is required to cover 100% of the base load and 95% of the peak load.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 356
Author(s):  
Paulina Szulc ◽  
Jędrzej Kasprzak ◽  
Zbysław Dymaczewski ◽  
Przemysław Kurczewski

The efficient and timely removal of organic matter and nutrients from water used in normal municipal functions is considered to be the main task of wastewater treatment plants (WWTPs). Therefore, these facilities are considered to be essential units that are required to avoid pollution of the water environment and decrease the possibility of triggering eutrophication. Even though these benefits are undeniable, they remain at odds with the high energy demand of wastewater treatment and sludge processes. As a consequence, WWTPs have various environmental impacts, which can be estimated and categorized using Life Cycle Assessment (LCA) analysis. In this study, a municipal WWTP based in Poznań, Poland, was examined using the method defined in ISO 14040. ReCiPe Endpoint and Midpoint (v1.11), in a hierarchical approach, were used to evaluate the environmental impacts regarding 18 different categories. All calculations were conducted using a detailed database from 2019, which describes each chosen facility. It was found that the energy component, related to the wastewater treatment process demand and electricity production, is the main determinant of the sum of the environmental impact indicators in light of the modelled energy mix. Therefore, it determines the entire process as an environmentally friendly activity.


1994 ◽  
Vol 30 (4) ◽  
pp. 125-132 ◽  
Author(s):  
D. Carnimeo ◽  
E. Contini ◽  
R. Di Marino ◽  
F. Donadio ◽  
L. Liberti ◽  
...  

The pilot investigation on the use of UV as an alternative disinfectant to NaOCI was started in 1992 at Trani (South Italy) municipal wastewater treatment plant (335 m3/h). The results collected after six months continuous operation enabled us to compare UV and NaOCl disinfection effectiveness on the basis of secondary effluent characteristics, quantify photoreactivation effects, evidence possible DBP formation and assess costs.


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