Increasing the efficiency of urban water systems is a growing concern for water utilities all over the world. Wastewater treatment plants (WWTPs) are critical in maintaining water quality and resource recovery, in a world confronted with growing challenges such as climate change, the water-energy-food nexus, and the expansion of legal requirements and user expectations.
As a result, implementing a plant performance assessment system (PAS) is critical, for assessing operating conditions and identifying critical aspects of the WWTPs, which can reduce its effectiveness, efficiency, and reliability.
Why there is a need of analysing the WWTP performance efficiency?
WWTPs are typically designed to only meet wastewater quality discharge permits (effectiveness), and not to keep costs to a minimum (efficiency). Good WWTP management is critical for balancing water pollution prevention, with the economic sustainability of these facilities. As a result, the performance efficiency of the WWTPs is extremely important.
Methods to analyse the wastewater treatment plant performance efficiency
The Performance Assessment System methodology is applied to a WWTP to determine, how the plant's efficiency and effectiveness could be improved. In a nutshell, the methodology consists of two stages (global and operational performance assessment).
1. The first is an annual evaluation of the WWTP's global performance (GP), in terms of removal efficiency and reliability, energy efficiency, and sludge management.
2. The second stage evaluates the system in terms of treated wastewater quality, removal efficiency, and operational conditions on a daily basis. Each individual operation/process is evaluated using performance indices (PX), which can range from 0 to 300, with a PX of 100 representing the minimum acceptable performance, and a PX of 300 representing excellent performance.
Values between 0 and 100 indicate poor performance, values between 100 and 200 indicate acceptable performance, and values between 200 and 300 indicate good performance. The PX are calculated by converting state-variable data expressing the relevant operational performance assessment, aspects of the WWTP into dimensionless performance indices. The type of performance function used is determined by the parameter being evaluated.
Treatment Processes on which performance efficiency relies!
The wastewater treatment process is divided into three stages: primary, secondary, and tertiary water treatment. Each of these stages targets a different type of pollutant, with water becoming cleaner, as it progresses through the stages.
· Water is temporarily held in a settling tank during primary treatment, where heavier solids sink to the bottom and lighter solids float to the surface.
· Secondary wastewater treatment works at a deeper level than primary treatment, and is intended to significantly degrade the biological content of the waste through aerobic/anaerobic biological processes. Secondary wastewater treatment allows for safer release into the local environment, by lowering common biodegradable contaminants to safe levels.
· The goal of tertiary wastewater treatment is to improve water quality to meet domestic and industrial standards, or to meet specific requirements for safe water discharge. In the case of municipally treated water, tertiary treatment also includes pathogen removal, ensuring that the water is safe for drinking.
What is plant performance efficiency in WWTPs?
Several studies have found that primary treatment has a removal efficiency ranging from 78% to 98%, and secondary treatment has a removal efficiency ranging from 7% to 20%.
What do we offer?
If you have any questions about wastewater treatment plants, their design, installation, commissioning, and services, or if you would like to discuss your specific needs, please contact the Netsol Water team right away. Our team is an expert in water and wastewater treatment, and can help you tailor a solution to your specific requirements.
We collaborate with our clients to design a customized solution that meets your specific requirements, as well as an on-going service plan to completely maintain your system.