Processes of transformation and removal of metals in constructed wetlands for effluent treatment from metallurgical industries

DI LUCA, G. A; MAINE, M. A.; SANCHEZ, G. C

Environment Science and Engineering. Vol. 4: Water Pollution & Waste Water Treatment

Studium Press LLC

Año: 2017; p. 1 - 27

This chapter describes the processes of transformation and removal of metals in constructed wetlands for wastewater treatment. These processes are described focusing on the role of wetland sediment/substrate. Moreover, two study cases of treatment wetlands are presented. The bottom sediment is primarily responsible for the removal of contaminants from water. Due to the electrochemical properties of the surface, the solid phase of the wetlands controls the adsorption, transformation, and release of metals towater. All these processes are governed by the properties of the sediment: redox potential, pH, caption exchange capacity, carbonates, Fe and Mn oxyhydroxides, clay minerals and fine size fractions. Two study cases in the metallurgical industry are described. Both systems are free-water Surface (FWS) constructed wetlands. Wastewater (with high pH and salinity containing Fe, Cr, Ni and Zn) and sewage were treated together. Contaminant removal efficiencies and contaminant retention by the sediment and/or plants are compared.