Heavy metals concentration and physical-chemical water quality of the Ciénaga Grande de Santa Marta

Abstract

The Ciénaga Grande de Santa Marta (CGSM) is an important ecosystem for the planet’s biodiversity. Anthropic activities increase levels of pollutants and affect the water quality, the inhabitants’ health and the environment. In order to determine the CGSM heavy metal content and water quality, samples were collected from nine sites. Temperature, total dissolved solids, hydrogen potential (pH), electrical conductivity, salinity, NH4+, PO43-, Ca+2, Mg+2, Na+, SO42-, N-NO3-, CO32-, HCO3-, Ni, Cd, Cr, Pb, total coliforms and thermotolerant coliforms were determined. The Pb, Cd, Cr, and Ni concentrations, did not exceed the reference value for seawater. The maximum concentration of Pb and Cd were observed in point 6 with 17.76 ppb and 0.48 ppb, respectively. Salinity correlated with Ni (0.98), pH with Ni and Cr contents (r = 0.99 and 0.43, respectively), OD was associated with Cd and Pb concentration (r = 0.72 and 0.67, respectively), TDS is associated with NI and Cr (r = 0.97 and 0.56, respectively), BOD with Cd concentration (r = 0.79). The heavy metals concentrations found, undoubtedly constitute an alert for the ecosystem due to the possible bioaccumulation in some environmental conditions and, it is reflection of the impact on parameters of water quality in the estuary, with the transport of organic matter, sediments, and nutrients inputs. High CT and CF values, affect ecosystem health.