MCQ Detailed View

Surface water is the water present on the Earth’s surface in rivers, lakes, ponds, and streams. It is an important source of freshwater for drinking, irrigation, and industry. The composition of surface water is influenced by natural processes and materials from the surrounding land.

One main component of surface water is dissolved salts. These salts come from the weathering of rocks and soil. As rainwater flows over rocks, it dissolves minerals such as calcium, magnesium, sodium, and potassium. These salts remain in water, contributing to its hardness and conductivity. The amount of salts in freshwater is usually low, but it can increase in areas with mineral-rich rocks.

Surface water also contains organic matter, which includes plant debris, algae, microorganisms, and other natural substances. Organic matter enters water through leaf fall, runoff, or decomposition of aquatic plants and animals. It affects the color, odor, and nutrient content of water. Organic matter supports the growth of aquatic life but can also increase biological activity, which must be managed in water treatment.

Additionally, surface water may have suspended impurities like silt or clay, which make water cloudy but do not dissolve. Despite these impurities, the primary constituents of surface water are dissolved salts and organic matter.

Understanding surface water composition is important in environmental chemistry and water management. It helps in assessing water quality, treating water for safe use, and protecting aquatic ecosystems. Knowledge of salts and organic matter ensures that water is suitable for human consumption and other uses.