Heavy metal removal from polluted waters using Schoenoplectus californicus and Phragmites australis

Acid mine drainage (AMD) is one of the most significant environmental challenges facing the mining industry worldwide. Furthermore, in many countries, the relationship between the mining industry, land, water, and communities is very close. In Peru this relationship goes beyond economic factors. Often, the negative effects of AMD can reduce the quality of water resources and affect communities. For this reason, many methods have been developed for AMD treatment, with wetlands being a good option for heavy metal removal. In wetlands, the use of green plants and their associated microbiota seems to be a good technique to remove, contain, or render harmless environmental contaminants. In this paper, we present the efficacy of Schoenoplectus californicus and Phragmites australis in a laboratory test for the removal of heavy metals from an aqueous solution. Both plants are Peruvian native Andean plants, and were tested using artificial solutions containing heavy metals such as copper, iron, lead, and zinc. From binary solutions of copper-iron, zinc-iron, and lead-iron, Schoenoplectus californicus removes 82%, 75%, and 88% of copper, zinc, and iron respectively; while the recovery of copper and lead in a quaternary solution of copper-zinc-lead-iron was 90 and 92% respectively. On the other hand, in the case of Phragmites australis, recoveries are slightly lower. From binary solutions the removal was 68% of copper, 53% of zinc, and 20% of lead; while the recovery in quaternary solutions was 97 and 95% for copper and zinc, respectively. Based on the results, it is concluded that Schoenoplectus californicus and Phragmites australis have a potential to be used in wetlands, especially in high Andean mining areas in Peru, to avoid possible contamination of natural water bodies in those areas.