ABSTRACT
This chapter examines the processes that control surface water contamination, focusing on contaminant interactions at both the water–atmosphere and water–soil interfaces. Within the water body, contaminants primarily disperse and migrate through convection, diffusion, and dispersion mechanisms. Additionally, contaminants can volatilize into the atmosphere, sorb into surrounding soil or solid matter present in the water, precipitate or dissolve in and out of the water, and transform through biodegradation and photolysis. The chapter also addresses water quality issues in three of the world’s major rivers: the Nile, the Amazon, and the Mississippi. It covers the geography and hydrology of each river, the importance and ecological significance of the resource, and specific water quality problems. The overview includes river length, tributaries, flooding patterns, and key basin features. Most pollution sources are related to human activities, such as industrial discharges, agricultural runoff, and sewage. Major contaminants include sediment, nutrients, pesticides, herbicides, heavy metals, and industrial chemicals. The studies advocate for comprehensive management strategies to reduce contaminant inputs and emphasize the need for collaboration among scientists, policymakers, and stakeholders.
