Assessment of heavy metals removal in a wastewater using aquatic ferns

Abstract

Aquatic ferns, which due to their rapid growth on the surface of the water in aquatic areas in many countries as an invasive species threaten the aquatic life and ecosystem of the regions, have the ability to remove heavy metals in wastewater. In this study, their use in removal of existing heavy metals in a domestic wastewater was experimented and the results proved their remarkable efficiency in treating such a wastewater. This research was conducted in two steps; laboratory and semi-industrial. Applying a jar testing apparatus was the first attempt in laboratory scale and optimization of the following four different factors by a routine procedure was the further goal: pH-value, reaction time, absorbent, pollutant concentration. Afterwards, it was scaled up by a real wastewater and removal efficiency was evaluated under optimum conditions designed by the basic experiments. In the second stage, the reactor was designed and constructed on a semi-industrial scale and the removal rate of contaminated metals was achieved. Focusing on the energy efficiency after the heavy metal removal in this method in comparison with another method (active sludge) can be considered to be suggested for treating domestic wastewaters which include considerable contents of heavy metals.