Texas Wastewater Class B Practice Exam

Which of the following can be used to dewater sludge?

1. Belt press, drying beds, solid bowl centrifuge, gravity thickener

2. Composting, incineration, filtration, sedimentation

3. Activated carbon treatment

4. Reverse osmosis

The correct answer is: Belt press, drying beds, solid bowl centrifuge, gravity thickener

The ability to dewater sludge effectively relies on methods that physically separate water from the solid waste material, which is a critical step in wastewater treatment processes. Utilizing a belt press, drying beds, solid bowl centrifuge, and gravity thickener are all established techniques for dewatering sludge. A belt press is a mechanical device that uses a series of belts and rollers to squeeze moisture from the sludge, thereby increasing the solids content. Drying beds utilize natural evaporation and drainage to reduce the moisture content in sludge over time. The solid bowl centrifuge employs centrifugal force to separate solid particles from the liquid, making it a highly efficient dewatering method. Gravity thickeners allow solids to settle out of the liquid based on density differences, thus achieving a degree of dewatering through sedimentation. The other methods mentioned in the alternatives serve different purposes within the treatment process. Composting is primarily for organic waste stabilization rather than dewatering. Incineration is a form of waste disposal through burning, which reduces volume but is not directly aimed at dewatering. Filtration and sedimentation might contribute to the separation of solids and liquids, but they are not specifically recognized as sludge dewatering methods in the same way as those in the first option. Activated carbon treatment and reverse os