scholarly journals Criticality Analysis Based on Reliability and Failure Propagation Effect for a Complex Wastewater Treatment Plant

2021 ◽  
Vol 11 (22) ◽  
pp. 10836
Author(s):  
Fredy Kristjanpoller ◽  
Nicolás Cárdenas-Pantoja ◽  
Pablo Viveros ◽  
Rodrigo Mena
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Real Data ◽  
Operational Effectiveness ◽  
Operational Conditions ◽  
Failure Propagation ◽  
And Performance ◽  
The Individual ◽  
Criticality Analysis

Wastewater treatment is a critical and necessary task every human settlement is obligated to address. If not, the consequences might be catastrophic, not just for humans but for the ecosystems as well, pushing research into finding new ways to improve wastewater treatment processes to make them safer and more efficient. Hence, there is a need to address matters, such as reliability and maintainability of Wastewater Treatment Plants (WWTP), when analyzing the availability and operational conditions. These should be addressed by analyzing the plant operational effectiveness impact (P-OEI), and in this article specifically, a WWTP study case to identify design flaws or improvement opportunities. A vital aspect of a complex system is to determine the contribution to resilience, reliability, and availability of every element embedded in the system. This is performed by adapting and applying the P-OEI methodology and real data of a WWTP located in Chile. This methodology breaks down the system into several levels of disaggregation similar to RBD methodology, analyzing the upstream for availability and the downstream for the P-OEI analysis from the system itself to the individual elements within subsystems. The potential impact on the overall system’s lack of efficiency is also quantified by an Expected Operational Impact (EOI) index, which is also calculated by the methodology. The P-OEI and EOI analyses performed in this study are powerful tools to assess the design and performance of complex systems and WWTP in particular.

scholarly journals LCA of a Membrane Bioreactor Compared to Activated Sludge System for Municipal Wastewater Treatment

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 421
Author(s):  
Dimitra C. Banti ◽  
Michail Tsangas ◽  
Petros Samaras ◽  
Antonis Zorpas
Keyword(s):  
Wastewater Treatment ◽  
Life Cycle ◽  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Real Data ◽  
Municipal Wastewater Treatment ◽  
Conventional Activated Sludge

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.

New simulators for the optimum management and operation of wastewater treatment plant

2001 ◽  
Vol 44 (2-3) ◽  
pp. 1-8
Author(s):  
E. Ayesa ◽  
G. Garralon ◽  
A. Rivas ◽  
J. Suescun ◽  
L. Larrea ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Real Data ◽  
Plant Operation ◽  
Plant Exploitation ◽  
Plant Data ◽  
The Common ◽  
Optimum Management ◽  
The Mathematical Model

This paper presents the basic description and the first full-scale implementation of a new kind of simulator specially designed to facilitate and improve the management and operation of modern wastewater treatment plants (WWTP). This new kind of simulator for plant operation is specifically adapted to every WWTP and the software is developed considering the common needs of the operators in plant exploitation. The internal structure of the plant operation simulator is based on a complete connection between the real data and the mathematical model of the plant. The software is then able to perform the processing, storage and management of the plant data and to predict the evolution of the process reading the required inputs from its stored files. The results obtained with the first application recommend the implementation of this new kind of simulators for plant operation in other treatment plants. However, it is important to note that the application of this technology implies a systematic and rigorous methodology in the acquisition and processing of the most significant plant data.

scholarly journals Evaluation of control strategies using an oxidation ditch benchmark

2002 ◽  
Vol 45 (4-5) ◽  
pp. 151-158 ◽  
Author(s):  
A. Abusam ◽  
K.J. Keesman ◽  
H. Spanjers ◽  
G. van Straten ◽  
K. Meinema
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
Treatment Plant ◽  
Electrical Energy ◽  
Performance Criteria ◽  
Oxidation Ditch ◽  
Flow Splitting ◽  
And Performance ◽  
Specific Oxidation

This paper presents validation and implementation results of a benchmark developed for a specific full-scale oxidation ditch wastewater treatment plant. A benchmark is a standard simulation procedure that can be used as a tool in evaluating various control strategies proposed for wastewater treatment plants. It is based on model and performance criteria development. Testing of this benchmark, by comparing benchmark predictions to real measurements of the electrical energy consumptions and amounts of disposed sludge for a specific oxidation ditch WWTP, has shown that it can (reasonably) be used for evaluating the performance of this WWTP. Subsequently, the validated benchmark was then used in evaluating some basic and advanced control strategies. Some of the interesting results obtained are the following: (i) influent flow splitting ratio, between the first and the fourth aerated compartments of the ditch, has no significant effect on the TN concentrations in the effluent, and (ii) for evaluation of long-term control strategies, future benchmarks need to be able to assess settlers' performance.

Microscopic and enzymatic investigations on biofilms of wastewater treatment systems

1997 ◽  
Vol 36 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Tanja Gschlößl ◽  
Ingrid Michel ◽  
Marion Heiter ◽  
Christian Nerger ◽  
Verena Rehbein
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Biological Properties ◽  
Organic Substances ◽  
Operational Conditions ◽  
Sludge Flocs ◽  
And Performance ◽  
The Stability

In biological wastewater treatment inorganic and organic substances are fixed and metabolized by mixed populations of microorganisms forming either activated sludge flocs or biofilms. Not only the type of wastewater but also the operational conditions promote the development of an adapted biocenosis of microorganisms with specialized enzymatic functions. Understanding the biological properties of the microorganisms, it is possible to assess the prevailing conditions in their natural environment. Regular microscopic and enzymatic investigations of activated sludge and biofilms thus improve the assessment of the stability of the processes and support troubleshooting in wastewater treatment plants. While the role of bacteria is often discussed, the importance of ciliated protozoes and metazoes for the maintenance of the stability of biofilm systems is rarely mentioned. In this paper we intend to show some new results of direct microscopic observations in different sorts of biofilm systems focussing upon ciliated protozoes and metazoes. Practical results will demonstrate the relation between enzymatic analysis, microscopic investigations and performance of biofilm systems.

Control of Activated Sludge Bulking: From the Lab to the Plant

1989 ◽  
Vol 21 (6-7) ◽  
pp. 717-726 ◽  
Author(s):  
R. Pujol ◽  
P. Boutin
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Common Type ◽  
Test Method ◽  
Mixing Zone ◽  
Operational Conditions ◽  
Sludge Bulking ◽  
Technical Aid

Activated sludge bulking often occurs in French wastewater treatment plants. Precise identification of filaments and better knowledge of their ecophysiology helped to clarify their re1ations with the operational conditions of plants. Effective techniques were therefore developed for control. The “mixing zone” is suitable for many cases of bulking ocurring in extended aeration plants (the most common type in France). A test method was developed to provide the elements for dimensioning the system. Unreserved cooperation between the owner of the plant, the manager, the SATESE (Service of technical aid to wastewater treatment plant managers) and specialized laboratories is required to implement such measures. Some cases, about which CEMAGREF was consulted, were examined; three of them are detailed and reasons for success or fai1ure are analysed. Seeking funds for the works too often leads to excessive delays.

Operational Conditions and Improvement Methods of Municipal Wastewater Treatment Plants under Low Temperatures in Northern China

2010 ◽  
Vol 113-116 ◽  
pp. 651-654
Author(s):  
Ben Chao Jiang ◽  
Fang Ma ◽  
Li Wei ◽  
Jing Bo Guo ◽  
Ang Li
Keyword(s):  
Wastewater Treatment ◽  
Low Temperature ◽  
Low Temperatures ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Northern China ◽  
Municipal Wastewater Treatment ◽  
Operational Conditions ◽  
Municipal Wastewater Treatment Plants

The minimum temperature in winter is under -30oC in the northern hilly regions. It is harmful for the municipal wastewater treatment in winter. According to previous reports, the effects caused by the low-temperature in municipal wastewater treatment plant are summarized, and improvements are put forward. Improving the efficiencies of municipal wastewater treatment is essential and significant in the northern hilly regions.

Inhibition of the Nitrification Process in Municipal Wastewater Treatment Plants by Industrial Discharges

1994 ◽  
Vol 29 (9) ◽  
pp. 69-77 ◽  
Author(s):  
H. Grüttner ◽  
M. Winther-Nielsen ◽  
L. Jørgensen ◽  
P. Bøgebjerg ◽  
O. Sinkjær
Keyword(s):  
Wastewater Treatment ◽  
Catchment Area ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Inhibitory Effect ◽  
Source Control ◽  
Municipal Wastewater Treatment ◽  
Inhibitory Effects ◽  
The Individual

More than three years of pilot-plant operation has documented that inhibition of nitrification was found to influence the dimensioning of the largest Danish wastewater treatment plant, which serves a major part of Copenhagen. Hence, a program for investigating the sources of substances inhibitory to nitrification was initiated. Since the number of substances potentially inhibitory to nitrification is very high, the investigations used direct testing of inhibitory effects on nitrification as a tool for the mapping operations. The overall purpose of the investigation was to determine the types of sources of inhibitory substances and to suggest a program for source control to be implemented by the individual municipalities in the catchment area. This paper describes the strategy for sampling and the results of the first two years of activity. Major conclusions have been that the most important sources of inhibitory substances are to be found among the industries, and that nearly all of the industries investigated exhibited some kind of inhibitory effect Further, is was demonstrated that the toxic unit calculation might be used in the quantification of the sources, and that the observed effects could be explained by the chemical substances in the wastewater from the industries. Based on the above described results, a strategy for control of the inhibitory effects at the different levels of the catchment area was suggested.

Catalytic reduction of nitrate in secondary effluent of wastewater treatment plants by Fe0 and Pd–Cu/γ–Al2O3

2016 ◽  
Vol 73 (11) ◽  
pp. 2697-2703 ◽  
Author(s):  
Yupan Yun ◽  
Zifu Li ◽  
Yi-Hung Chen ◽  
Mayiani Saino ◽  
Shikun Cheng ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Reaction Time ◽  
Wastewater Treatment Plants ◽  
Catalytic Reduction ◽  
Nitrate Removal ◽  
Treatment Plant ◽  
Catalytic Performance ◽  
Secondary Effluent ◽  
Mass Ratio ◽  
Operational Conditions

Total nitrogen, in which NO3− is dominant in the effluent of most wastewater treatment plants, cannot meet the requirements of the Chinese wastewater discharge standard (&lt;15 mg/L), making nitrate (NO3−) elimination attract considerable attention. In this study, reductant iron (Fe0) and γ–Al2O3 supported palladium–copper bimetallic catalysts (Pd–Cu/γ–Al2O3) were innovatively used for the chemical catalytic reduction of nitrate in wastewater. A series of specific operational conditions (such as mass ratio of Pd:Cu, catalyst amounts, reaction time and pH of solution) were optimized for nitrate reduction in the artificial solution, and then the selected optimal conditions were further applied for investigating the nitrate elimination of secondary effluent of a wastewater treatment plant in Beijing, China. Results indicated that a better catalytic performance (74% of nitrate removal and 62% of N2 selectivity) could be obtained under the optimal condition: 5 g/L Fe0, 3:1 mass ratio (Pd:Cu), 4 g/L catalyst, 2 h reaction time and pH 5.1. It is noteworthy to point out that nitrogen gas (N2) predominated in the byproducts without another system to treat ammonium and nitrite. Therefore, the chemical catalytic reduction combining Fe0 with Pd–Cu/γ–Al2O3 could be regarded as a better alternative for nitrate removal in wastewater treatment.

scholarly journals Elimination of nitrate in secondary effluent of wastewater treatment plants by Fe0 and Pd-Cu/diatomite

2016 ◽  
Vol 8 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Yupan Yun ◽  
Zifu Li ◽  
Yi-Hung Chen ◽  
Mayiani Saino ◽  
Shikun Cheng ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Reaction Time ◽  
Nitrate Reduction ◽  
Wastewater Treatment Plants ◽  
Copper Catalyst ◽  
Nitrate Removal ◽  
Treatment Plant ◽  
Secondary Effluent ◽  
Mass Ratio ◽  
Operational Conditions

Abstract Because total nitrogen (TN), in which nitrate (NO3–) is dominant in the effluent of most wastewater treatment plants, cannot meet the requirement of Chinese wastewater discharge standard (&lt;15 mg/L), NO3– elimination has attracted considerable attention. In this research, the novel diatomite-supported palladium-copper catalyst (Pd-Cu/diatomite) with zero-valent iron (Fe0) was tried to use for catalytic reduction of nitrate in wastewater. Firstly, specific operational conditions (such as mass ratio of Pd:Cu, catalyst amounts, reaction time and pH of solution) were optimized for nitrate reduction in artificial solution. Secondly, the selected optimal conditions were further employed for nitrate elimination of real effluent of a wastewater treatment plant in Beijing, China. Results showed that 67% of nitrate removal and 62% of N2 selectivity could be obtained under the following conditions: 5 g/L Fe0, 3:1 mass ratio (Pd:Cu), 4 g/L catalyst, 2 h reaction time and pH 4.3. Finally, the mechanism of catalytic nitrate reduction was also proposed.

scholarly journals Designed and real hydraulic load of household wastewater treatment plants

2019 ◽  
Vol 40 (1) ◽  
pp. 155-160 ◽  
Author(s):  
Piotr M. Bugajski ◽  
Karolina Kurek ◽  
Dariusz Młyński ◽  
Agnieszka Operacz
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
Sewage Treatment Plants ◽  
Household Wastewater ◽  
Hydraulic Load ◽  
The Individual ◽  
Research Period ◽  
Annual Period

Abstract The paper presents the results of the analysis concerning the verification of the actual hydraulic load and the load of organic pollutants compared to the conditions designed for 4 household wastewater treatment plants. The researches were carried out in the annual period from May 2015 to April 2016. Based on the conducted analysis, it was found that objects act as underloaded hydraulically and the actual inflow of sewage to the analysed objects during the research period ranged from 7.3% to 32.7% in relation to the inflow assumed in the project. Furthermore, in the case of loading the treatment plant with the load of pollutants expressed as PE, it was fund that the actual PE values were lower than assumed in the project. Therefore, it is important that the sizes of the series of household sewage treatment plants were selected depending on the individual conditions of household, i.e. the number of inhabitants or the amount of consumed water.

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