scholarly journals Ozone and Photocatalytic Processes for Pathogens Removal from Water: A Review

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 46 ◽  
Author(s):  
João Gomes ◽  
Ana Matos ◽  
Marta Gmurek ◽  
Rosa M. Quinta-Ferreira ◽  
Rui C. Martins
Keyword(s):  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Cost Effective ◽  
Municipal Wastewater Treatment ◽  
Treated Water ◽  
Advantages And Disadvantages ◽  
Alternative Water ◽  
Municipal Wastewater Treatment Plants ◽  
High Doses

The search for alternative water sources is pushing to the reuse of treated water coming from municipal wastewater treatment plants. However, this requires that tightened standards be fulfilled. Among them is the microbiological safety of reused water. Although chlorination is the mostly applied disinfection system, it presents several disadvantages, such as the high doses required and the possibility of formation of dangerous by-products. Moreover, the threat of antibiotic resistance genes (ARGs) spread throughout poorly treated water is requiring the implementation of more efficient disinfection systems. Ozone and photo assisted disinfection technologies are being given special attention to reach treated water with higher quality. Still, much must be done to optimize the processes so that cost-effective systems may be obtained. This review paper gives a critical overview on the application of ozone and photo-based disinfection systems, bearing in mind their advantages and disadvantages when applied to water and municipal wastewater. Also, the possibility of integrated disinfection systems is considered.

scholarly journals Bio-Methanol Production Using Treated Domestic Wastewater with Mixed Methanotroph Species and Anaerobic Digester Biogas

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1414 ◽  
Author(s):  
I-Tae Kim ◽  
Young-Seok Yoo ◽  
Young-Han Yoon ◽  
Ye-Eun Lee ◽  
Jun-Ho Jo ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Cost Effective ◽  
Treated Wastewater ◽  
Culture Solution ◽  
Municipal Wastewater Treatment ◽  
Mineral Salts ◽  
Methanol Production ◽  
Municipal Wastewater Treatment Plants

The development of cost-effective methods, which generate minimal chemical wastewater, for methanol production is an important research goal. In this study, treated wastewater (TWW) was utilized as a culture solution for methanol production by mixed methanotroph species as an alternative to media prepared from commercial or chemical agents, e.g., nitrate mineral salts medium. Furthermore, a realistic alternative for producing methanol in wastewater treatment plants using biogas from anaerobic digestion was proposed. By culturing mixed methanotroph species with nitrate and phosphate-supplemented TWW in municipal wastewater treatment plants, this study demonstrates, for the first time, the application of biogas generated from the sludge digester of municipal wastewater treatment plants. NaCl alone inhibited methanol dehydrogenase and the addition of 40 mM formate as an electron donor increased methanol production to 6.35 mM. These results confirmed that this practical energy production method could enable cost-effective methanol production. As such, methanol produced in wastewater treatment plants can be used as an eco-friendly energy and carbon source for biological denitrification, which can be an alternative to reducing the expenses required for the waste water treatment process.

Ultraviolet Disinfection in Municipal Wastewater Treatment Plants

1990 ◽  
Vol 22 (7-8) ◽  
pp. 145-152 ◽  
Author(s):  
Jan Maarschalkerweerd ◽  
Rory Murphy ◽  
Gail Sakamoto
Keyword(s):  
Wastewater Treatment ◽  
Fecal Coliform ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Cost Effective ◽  
Uv Disinfection ◽  
Municipal Wastewater Treatment ◽  
Capital Costs ◽  
Effective Manner ◽  
Municipal Wastewater Treatment Plants

Pilot and full-scale studies of UV disinfection of wastewater have demonstrated that the process could consistently meet an effluent fecal coliform standard of 200/100 mL or less, depending on suspended solids and UV transmission. Since 1984 over three hundred systems have been installed at municipal wastewater treatment plants in North America. The majority of these are in treatment plants which have been using chlorination. The UV systems have been retrofitted into the existing chlorine contact tanks or existing channels. The capital costs of retrofitting compare favourably to the costs of upgrading chlorination systems, especially when de-chlorination equipment is required. As experience is gained in the operation of these UV systems, their performance has been monitored for their disinfection efficiency and cost of operation. Several installations are examined and their performance and costs analyzed. The evidence to date supports the premise that UV disinfection can meet demands for reliable effluent disinfection in a cost effective manner.

scholarly journals Economic Analysis: Trickling Filter/Activated Sludge or Nitrifying Trickling Filter/Activated Sludge?

2019 ◽  
Vol 26 (2) ◽  
pp. 345-356
Author(s):  
Shahryar Jafarinejad
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Cost Effective ◽  
Municipal Wastewater Treatment ◽  
Trickling Filter ◽  
Operational Conditions ◽  
Project Construction ◽  
Municipal Wastewater Treatment Plants ◽  
Total Project

Abstract The performance and economic simulation and modeling are crucial for accurate and rapid designing, construction, and forecasting future economic needs of municipal wastewater treatment plants (MWWTPs). In this study, combined nitrifying trickling filter/activated sludge (NTF/AS) process was suggested for the modernization of a MWWTP and the performance and economics of MWWTPs based on the combined TF/AS process and combined NTF/AS process were analyzed and compared. In real, the performance, total project construction, total operation labor, total maintenance labor, total material, total chemical, total energy, and total amortization costs of these proposed MWWTPs were calculated and compared. Under the used design criteria and operational conditions in this study, the project construction cost of the MWWTP based on TF/AS was 15.25 % higher than that of the MWWTP based on NTF/AS. Also, MWWTP based on NTF/AS was cost effective and the material and amortization costs for both plants were higher in comparison with the operation, maintenance, energy, and chemical costs. It is necessary to note that this study is a computer simulation for a case and drawing general conclusions only on the basis of this simulation may be insufficient.

scholarly journals Intensification of activated sludge sedimentation processes by means of vacuuming

Vestnik MGSU ◽  
2021 ◽  
pp. 370-380
Author(s):  
Artem A. Kulakov ◽  
Alina F. Filatova
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Settling Tank ◽  
Municipal Wastewater Treatment ◽  
Treated Water ◽  
Mixed Liquor ◽  
Municipal Wastewater Treatment Plants ◽  
Secondary Settling

Introduction. The mixed liquor of nitrogen removal wastewater treatment plants is characterized by a high concentration of nitrates and dissolved oxygen at the inlet to the secondary settling tank. In the sludge layer of secondary sedimentation tanks, conditions of decreased oxygen content and uncontrolled denitrification processes take place. This leads to the floating up and removal of sludge with the effluent and secondary pollution of treated water. The purpose of this article is to study the parameters of activated sludge sedimentation in municipal wastewater treatment plants and their intensification by means of vacuuming. Materials and methods. The studies were carried out under laboratory conditions. Activated sludge vacuuming and sedimentation processes were simulated. Diagrams of the “sludge-water” phase reduction (Kinsh curves) were drawn. Mathematical and graphic processing of the results was carried out. Results. Biological treatment of municipal wastewater (aerotank — secondary settling tank) and methods of its intensification by influencing the activated sludge were considered in this article. Trends of activated sludge (at different concentrations of mixed liquor suspended solids) sedimentation were experimentally obtained for municipal wastewater treatment plants. The process of sludge vacuuming was researched, the process efficiency was determined as a function of the treatment time. Conclusions. Vacuuming allows removing gases from the fluid, which accelerates the process of sludge separation from the treated water and prevents it from floating to the surface. The treated sample is characterized by better sedimentation characteristics, density, coarseness and integrity of flakes. The optimal duration of mixed liquor vacuuming before sedimentation is 0.5 minutes; this accelerates the processes of subsequent sedimentation and reduces the removal of sludge with treated water. The results of laboratory tests can be applied to the design of the mixed liquor vacuuming unit before the secondary sedimentation tanks and its sludge separation.

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