Abstract
Arsenic (As) is a natural component of the Earth’s crust. Due to its specific properties, arsenic became e.g. the favorite poison in the 19th century in Europe, a component of an effective insecticide and herbicide in agriculture, a specific chemical weapon during World War II and a medication used to treat various diseases. The bad reputation of this element was confirmed after World War II, when arsenic-based chemical weapons were dumped on the seabed and became a potential threat to the marine ecosystem. The wide distribution of arsenic compounds in the environment necessitated the development of technologies aimed at removing arsenic from the aquatic ecosystem. This study provides a detailed overview of the occurrence, distribution and transformation of arsenic species in the aquatic environment.