Final answer:
The activated sludge process is a wastewater treatment method where the Solids Residence Time (SRT) affects the effluent BOD5 levels. While a plot cannot be shown here, longer SRTs generally result in lower BOD5 due to enhanced digestion of organic matter.
Step-by-step explanation:
Activated Sludge Process and Solids Residence Time
The activated sludge process is a key component in modern wastewater treatment. This process involves the use of aerobic bacteria to break down organic matter, with the amount of time the solids (activated sludge) remain in the system being an important factor. This is known as the Solids Residence Time (SRT). The question pertains to plotting the effluent BOD5, which is a measure of the biodegradable organic matter in the wastewater, against different SRTs ranging from 1 to 20 days. While the actual plot cannot be created here, we can discuss that longer SRTs typically allow for more complete digestion of organic matter, which should result in a lower effluent BOD5. The provided kinetic parameters such as microbial growth rate (Y), half-saturation coefficient (Ks), and decay coefficient (b) are used to describe the system's biological activity and can be applied in models to predict performance.
As solids are processed, in solids processing facilities like digesters, they undergo further reduction in volume and are treated to reduce odors and eliminate disease-causing organisms. This is an essential step in ensuring the treated water and byproducts are safe for disposal or use as fertilizer, after careful testing for contaminants.
Secondary treatment, which includes aeration and clarification, assists in the reduction of BOD5 by facilitating the growth and activity of microorganisms that digest organic pollutants. By plotting the effluent BOD5 against the SRT, engineers can optimize the treatment process to ensure regulatory compliance and environmental protection.