Assessment of toxicity of residues of normal/green cracker and their impact on soil

Abstract

In the present work, laser-induced breakdown spectroscopy (LIBS) is used to examine the hazardous constituents present in the residues of six types of normal and six types of green firecracker samples. The residue of the normal firecracker’s samples contains the spectral lines of toxic chemicals such as Al, Ba, Sr, Mg, and Ti in a similar way as the fresh powder of normal crackers. The residues of the green firecracker’s samples contain toxic elements such as Al and Ba, and the intensities of these toxic elements are so high that these samples also contain the electronic bands of AlO and SrO. The UV-vis spectra of residues of normal and green firecracker samples contain the molecules of KNO3, CaO, Al2O3, and SrO in a similar way as the fresh powder of these firecrackers does. This reflects that the toxicity of the powder of firecracker samples remains similar after the burning of these firecrackers’ samples. Therefore, these toxic residues are mixed in the soil, where they burn and contaminate it. For the assessment of the contamination of the soil, the concentration of micronutrients such as Fe, Cu, Mn, Zn, and P is calculated using atomic absorption spectroscopy (AAS) techniques and found to increase in all the contaminated soil compared to blank soil. This reflects that the soil is contaminated. For the classification of the residues and soil contaminated with residues, the principal component analysis (PCA) and hierarchical clustering analysis (HCA) are applied to the LIBS data set.