If a large quantity of acid waste is discharged into a sanitary sewer, how can its arrival at a wastewater treatment plant be determined?

If a large quantity of acid waste is discharged into a sanitary sewer, how can its arrival at a wastewater treatment plant be determined?

• A. The pH of the raw wastewater would rise
• B. The pH of the raw wastewater would fall
• C. The volatile portion of the suspended solids would increase
• D. The dissolved oxygen would exceed the saturation value

Answer: (B)

When a large quantity of acid waste is discharged into a sanitary sewer, it introduces a significant amount of hydrogen ions (H+) into the wastewater. This increase in acidity lowers the pH of the wastewater, making it more acidic. The pH is a measure of how acidic or basic a solution is, and a drop in pH indicates an increase in acidity. As this acidic waste travels through the sewer system towards the wastewater treatment plant, operators can monitor the pH levels of the incoming wastewater. A noticeable decrease in the pH would signal the arrival of the acid waste. Wastewater treatment facilities often have systems in place to measure and record pH levels continuously, allowing them to identify and respond to fluctuations directly related to discharges such as acid waste. In contrast, other indicators such as an increase in the volatile portion of suspended solids or dissolved oxygen levels exceeding saturation may not directly correlate to the expected effects of decreased pH from the arrival of acid waste. Therefore, the falling pH is the most reliable indicator for determining the presence and effects of large quantities of acid waste in raw wastewater.

When a large quantity of acid waste is discharged into a sanitary sewer, it introduces a significant amount of hydrogen ions (H+) into the wastewater. This increase in acidity lowers the pH of the wastewater, making it more acidic. The pH is a measure of how acidic or basic a solution is, and a drop in pH indicates an increase in acidity.

As this acidic waste travels through the sewer system towards the wastewater treatment plant, operators can monitor the pH levels of the incoming wastewater. A noticeable decrease in the pH would signal the arrival of the acid waste. Wastewater treatment facilities often have systems in place to measure and record pH levels continuously, allowing them to identify and respond to fluctuations directly related to discharges such as acid waste.

In contrast, other indicators such as an increase in the volatile portion of suspended solids or dissolved oxygen levels exceeding saturation may not directly correlate to the expected effects of decreased pH from the arrival of acid waste. Therefore, the falling pH is the most reliable indicator for determining the presence and effects of large quantities of acid waste in raw wastewater.