Recovery, modifications, physicochemical properties, and MB removal efficiency of marble waste powder

A large quantity of marble waste is produced worldwide which imposes serious environmental problems. The marble rocks are made of valuable inorganic oxides and carbonates. Unfortunately, the recovery of marble waste is only limited to mechanical uses. However, the elemental composition-based chemical uses are still not being studied widely. The present study investigates the one-step recovery of marble waste powder (MWP), a byproduct of the marble industry. The study involves the modification of waste powder using high-temperature treatment (i.e., 110-1000 °C). The waste powder samples were characterized using different techniques such as FT-IR, XRD, TGA, DTA, SEM, EDX, and PL. The physicochemical characterizations confirm the existence of various valuable elements such as Ca, Al, Mg, Si, Fe, C, O, and I, associated with the oxides and carbonate compounds. The EDX elemental composition results indicated that calcium is a major component of the waste powder in the form of calcium carbonate and dolomite. Similarly, the FTIR results revealed that the high-temperature treatments showed the conversion of CaCO3 to CaO. The modified waste powder samples were tested for the removal of model dye, Methylene Blue (MB), and the removal efficiency results indicated as much as 93% removal by the high-temperature calcined sample (1000 °C). The present study illustrates the potential significance of marble waste powder, which not only facilitates the recovery of important elements but can also be used for various practical applications.