Use of coal mining waste for river water treatment and evaluation of this process using physicochemical parameters and bioassays

Abstract

This work aimed to use calcinated coal mining waste to treat river water contaminated by residues derived from coal mines. Water samples from the Urussanga River (Urussanga, Santa Catarina state, Brazil) were collected. The pH values and the concentrations of aluminum, iron and manganese were determined before and after the treatment. Additionally, acute toxicity tests (CL50) were carried out in the microcrustaceans Artemia sp. and Daphnia magna along with root growth inhibition tests of Allium cepa L. and plasmid DNA cleavage assays. The results demonstrate that the treatment resulted in an increase in the pH and an expressive removal of metals. It was observed that the untreated water caused significant toxicity in Artemia sp., Daphnia magna and Allium cepa L. as well as fostering damage to plasmid DNA. However, after the treatment was detected reduction of the toxicity. It was concluded that the calcinated coal mining waste can be used as alternative system for the treatment of waters affected by coal mining contaminants, while the bioassays consists of an excellent tool for the evaluation of this process.