Ontario Operator-in-Training (OIT) Practice Exam

What is the main purpose of adding chemicals to sludge during dewatering?

1. To enhance its biomass content

2. To assist in the dewatering process

3. To neutralize odors

4. To facilitate its disposal

The correct answer is: To assist in the dewatering process

The main purpose of adding chemicals to sludge during dewatering is to assist in the dewatering process. When sludge is subjected to dewatering, chemicals are often introduced to improve the separation of water from the solids. These chemicals, such as coagulants or flocculants, help to bind the particles together and create larger aggregates, which can be more easily removed from the liquid. This results in a more efficient dewatering process, reducing the volume of water that needs to be managed and improving the overall treatment efficiency. While other aspects like odor neutralization and facilitating disposal may be relevant in different contexts, they are not the primary objective when it comes to the role of chemicals in sludge dewatering. The focus remains predominantly on improving the efficiency and efficacy of the water removal from the sludge, making it more manageable for subsequent processing or disposal.