What is the optimal range of parameters for the activated sludge process?

In the activated sludge process, maintaining optimal environmental conditions is crucial for enhancing the efficiency of microbial activity responsible for wastewater treatment. The correct choice reflects well-established parameters that promote effective biological treatment.

Dissolved oxygen (DO) levels are vital for the survival of aerobic microorganisms, which play a key role in breaking down organic materials in wastewater. An optimal DO range of around 2 ppm strikes a balance necessary for microbial respiration without promoting excess aeration that could lead to energy inefficiencies.

The pH level also significantly affects microbial activity. A pH of 7.0 is considered neutral and typically supports a wide variety of microorganisms involved in the activated sludge process. This neutrality helps maintain microbial health and process stability.

Temperature, measured in degrees Fahrenheit, is another critical factor, as it influences the metabolic rates of the microorganisms. A temperature range of 80-95°F (approximately 27-35°C) is generally optimal, with heat facilitating faster biochemical reactions and, thus, more effective treatment of wastewater.

The combination of these parameters—2 ppm DO, a neutral pH of 7.0, and a temperature between 80-95°F—creates an ideal environment for the microbial population to flourish, leading to better treatment efficiency.