According to USEPA standards, what is the required pH range for secondary treatment effluent?

The required pH range for secondary treatment effluent, according to USEPA standards, is 6 to 9. This range is established to ensure that the treated wastewater is within acceptable limits for environmental discharge and to protect aquatic life. A pH outside this range could adversely affect the biological treatment processes and potentially harm the receiving water bodies.

In most wastewater treatment processes, maintaining the pH within this specified range is crucial because it affects the solubility and toxicity of various pollutants. A pH that is too low or too high can hinder the removal of contaminants and can also be detrimental to aquatic ecosystems if the effluent is released into natural waters.

The other options specify narrower pH ranges that do not align with the broader standards set by the USEPA for secondary treatment effluent. By adhering to the pH specification of 6 to 9, facilities can ensure that their effluent is safe for discharge and complies with regulatory requirements.