Tennessee Wastewater Operator Practice Exam

To address slimy foam caused by wastewater from a fruit processing plant, what action is recommended?

1. Increase aeration

2. Add missing nutrients

3. Reduce sludge wasting

4. Increase temperature

The correct answer is: Add missing nutrients

To address slimy foam in wastewater treatment, particularly from a fruit processing plant, adding missing nutrients is a vital action. This type of foam is often an indicator of imbalanced biological processes, where microorganisms are experiencing nutrient limitations. In the case of fruit processing, the wastewater may lack essential nutrients such as nitrogen or phosphorus necessary for the healthy growth and functioning of the microbial community. By adding these missing nutrients, you support the growth of a diverse and balanced microbial population, enabling them to effectively break down organic matter from the wastewater. This can lead to improved floc formation and stability, thereby reducing foam production. In contrast, increasing aeration primarily serves to enhance oxygen availability, which may not address the underlying nutrient deficiency causing the slimy foam. Reducing sludge wasting might further upset the balance of microbial populations, while increasing temperature could potentially stress the microorganisms or affect their metabolism adversely if it's above optimal levels for the specific microbial communities involved. Thus, addressing nutrient limitations directly alleviates the foam issue effectively.