Aquatic animals need oxygen to survive. Oil spills can have a severe impact on aquatic life, causing a drastic reduction in the number of aquatic animals. The oil spills tend to hinder dissolved oxygen transfer in the water.Even small amounts of hydrocarbons can prevent oxygen from transferring in the water column.The oil layer directly can also cause the dissolved oxygen level in the water to become low due to the obstruction of the diffusion process from the air.

Nitrification in water bodies is caused by nitrifying bacteria converting ammonia and other nitrogen compounds into nitrite and nitrate. This process is affected by several environmental factors, including temperature, oxygen, pH, and light.

Detoxification of water is the process of removing harmful components from wastewater. This process is necessary to treat water and wastewater that contain toxic compounds that can harm human health and the environment.

Water disinfection occurs when physical or chemical processes disrupt the cell walls or membranes of microorganisms. This prevents the microorganisms from multiplying and causes them to die.