Final answer:
The sediment load that carries electrically charged ions is known as the dissolved load. It includes soluble materials that become part of the water composition after being chemically eroded from rocks, such as various minerals in ionic forms.
Step-by-step explanation:
Understanding Sediment Loads in Waterways
The types of sediment load in waterways include the bed load, suspended load, and dissolved load. The dissolved load specifically refers to the portion of a river's sediment load that carries electrically charged ions. This form of sediment consists of soluble materials that become incorporated into the water, such as calcium, sodium, and bicarbonate ions, among others. The dissolved minerals are a product of chemical weathering of rocks and are transported by the water in an ionic state.
Load casts form when denser sediment, such as sand, overlays lighter sediment, creating distinctive structures due to the weight of the denser material pressing into the underlying softer layers. These features are often seen in sedimentary rocks and can provide information about ancient depositional environments.
Aggregation and precipitation occur when the charged surfaces of particles, such as those of clay in a colloidal suspension, become neutralized by opposite charged ions. This can lead to the formation of land at the mouths of rivers, known as deltas, wherein suspended particles settle out of the water column due to charge neutralization, a process valuable in various industrial applications for particle removal.