A model of eco-friendly cooking stove and a potential application of soot for remediation of heavy metals in the environment

Abstract

ABSTRACT Unplanned industrial and urban development are the main sources of increasing concentration of soot and heavy metals in the environment. These pollutants have instigated the deleterious impacts on the environment. Over the past few decades, many researchers have proposed different methods to bring improvement in the environmental quality. These methods include effective combustion techniques that produce less soot and the methods of using soot in the decontamination of environmental compartments polluted with the heavy metals. The aim of this paper is twofold. Firstly, we present a model of an eco-friendly cooking stove to overcome the problem of domestic soot emissions. The proposed model of stove uses a typical type of vented soot filtration hood which contains the soot particulate filters to effectively control soot emissions. Secondly, we study the remediation efficiency of plastic fuel derived soot for heavy metals lead (Pb), nickel (Ni), and chromium (Cr) from the aqueous solutions, contaminated soil, and wastewater samples. A series of batch adsorption experiments are conducted to analyze the effect of different parameters on the heavy metals uptake from aqueous solutions and wastewater samples. The effect of soot application on the heavy metals immobilization from the contaminated soil samples is also studied by using the EDTA extraction method. Experimental results reveal that pH 9.0 is optimal for the adsorption of heavy metals from the aqueous solutions. Soot application to the soil samples increased the pH and reduced 0.1 M EDTA extractable concentration of heavy metals. From the water samples, adsorption of heavy metals increased by increasing the contact time and maximum adsorption occurred at the optimum contact time of 3 hours. Moreover, the experimental data are well modeled through the Langmuir and Freundlich isotherm models. The overall effectiveness of soot in reducing the concentration of heavy metals from aqueous solutions, soil samples, and water samples is as follows: Pb (94.4%, 75%, and 90.5%), Ni (69.97%, 37.4%, and 69.8%), and Cr (61.3%, 37.5%, and 82.6%). It has been inferred from results of this study that soot has a great potential as a remediation tool for the environment excessively contaminated with heavy metals.