How are air and water pollution different?
Air pollution moves fast, water pollution does not (especially groundwater pollution).
Air contaminants (whether particulate or gaseous) travel quite fast. Sooner or later particulate matter settles down. Therefore such particulates might cause water pollution when they settle down. Gases stay in the atmosphere for a long time (such as ever increasing carbon dioxide concentration in the atmosphere).
Water contaminants can be divided into eight groups (such as decaying organic material, sediment pollution, and thermal pollution). Rivers can cleanup themselves if and only if their assimilation capacity are not harmed and good enough to clean up biodegradable water pollutants. Groundwater does not move rapidly compared to rivers. Moreover, groundwaters are not well oxygenated. Therefore, groundwater resources are difficult to clean up when they are polluted.
There are other factors related to air and water pollution.