Potential Ecological Risk Assessment of Critical Raw Materials: Gallium, Gadolinium, and Germanium.

In recent years, the demand for critical raw materials such as gallium, gadolinium and germanium (G(s)) has steadily increased in various industries. However, treatment or recycling rates of these elements are extremely low, which can lead to environmental pollution. An assessment of the ecological risks was also not possible until now, as there were no calculated toxicity coefficients for G(s). In this study, a well-known method, the so-called potential ecological risk index (PERI), was used for the first time to calculate the toxicity coefficients of these elements using data from recent literature studies on G(s) elements. The toxicity coefficient of each of the three elements was determined as five (5). The results show that G(s) have the same toxicity coefficient as Cu and Pb and are higher than that of Cr. The ecological risk index results varied from 4 to 414, 0.98 to 25.98 and 2.50 to 284.64 for Ga, Gd and Ge, respectively. The results show that Ga and Ge pose high ecological risk while the Er i of Gd is low. The toxicity coefficients of these elements have been calculated for the first time in the literature and provide a practical use for calculating the potential ecological risk index.