Pyritization of trace metals in mangrove sediments

Abstract

The present study investigates the levels of Mn, Zn, Ni, and Co pyritization in mangrove sediments along distinct sedimentary zones in Enseada das Gracas, a lagoon-type estuary located on the southeastern coast of Brazil. The coastal geology is characterized by intense interactions of trace metals, forming pyrite minerals. Specific orders of DOP (degree of pyritization) and DTMP (degree of trace-metal pyritization) are shown: supratidal flat < mangrove forest < mud flat. Distinct changes in content along the sediment profiles are noted, where a supratidal flat presented low levels of DOP and DTMP with little variance along the sedimentary depths. The mangrove forest showed relatively high values of DOP and DTMP in the lower depths, while the mud flat showed the highest levels of DOP and DTMP.