Using LIBS for monitoring and estimation of heavy elements in industrial wastewater during its remediation

Industrial wastewater contains heavy metals such as (Pb, Zn, Ni, Cd, Cr, and Co) that cause a significant danger to the whole ecosystem, including human health. In dealing with such a problem, it is necessary to control the pollution at the source and achieve real-time and online monitoring. In the present study laser-induced breakdown spectroscopy (LIBS) technique has been used as a diagnostic tool for estimating heavy elements concentration in the wastewater before and after treatment. For this purpose, bentonite clay has been used as an efficient absorber to remove heavy metals from wastewater. Therefore, the adsorption efficiency of bentonite clay for the existing heavy metals was studied experimentally in detail. In addition, influencing parameters such as pollutants concentration and adsorbent dose have been investigated. Synthetic wastewater has been used to construct calibration curves for each heavy element under investigation. Calibration curves for different elements were used to quantitatively analyze the heavy elements in industrial wastewater before and after treatment with bentonite clay. The results obtained via LIBS analysis have been validated by examining some samples via ICP-MS. Good agreement has been obtained between the results of both techniques, revealing the potential of using Bentonite clay efficiently in heavy elements remediation of the industrial wastewater. On the other hand, adopting LIBS in estimating and monitoring such pollutants has proved its feasibility in environmental applications.