A trace element refers to a type of chemical element whose concentration in the environment is very low. Different types of trace elements have been divided into two categories, namely, essential trace elements and non-essential trace elements. Natural processes and anthropogenic activities are responsible for the release of trace elements in the environment. Arsenic (As), antimony (Sb), cadmium (Cd), chromium (Cr), and lead (Pb) are some of the trace elements that deteriorate the quality and properties of soil. The biogeochemistry of trace elements from soils to rivers is studied for its impact on aquatic ecosystem toxicity. Microbes are crucial in the biogeochemical cycling of trace elements. The global biogeochemical cycle of trace elements is dependent on the speciation, mobility and bioavailability of microbes. This book provides a detailed explanation of the various trace elements found in the environment along with their biogeochemical and biotechnological aspects. It will provide comprehensive knowledge to the readers.