How is 'particulate matter' defined in the context of water quality?

Particulate matter in the context of water quality refers specifically to small solid or liquid particles that are suspended within water. This definition encompasses a variety of substances including sediment, organic matter, and microorganisms, which can significantly affect water quality.

These particles can originate from numerous sources such as soil erosion, wastewater discharge, and urban runoff. The presence of particulate matter is important to monitor because it can carry pollutants, affect the water's physical characteristics (like turbidity), and influence the health of aquatic ecosystems.

In contrast, large solid objects floating in water would not be classified as particulate matter, as they do not fit the definition of small particles that are suspended. Similarly, fluid materials that contribute to water flow pertain more to the movement of water itself rather than the suspended particles within it. Finally, gel-like substances that form on the surface of the water involve a different phenomenon, such as algal blooms or biofilms, which don't fit the definition of particulate matter. Thus, option B accurately captures the essence of particulate matter within the realm of water quality assessment.