SORPTION CAPACITY INCREASING OF SPENT CATALYST ZEOLITE BY USING H2O2 AND ULTRASOUND
The synthetic zeolite Y (Na56[(AlO2)56(SiO2)136]×250H2O) is used as an adsorbent for petroleum refining during catalytic cracking, and after a certain time it contaminates and becomes a waste. This waste in Lithuania can make up to 200 tons per year. The EU environmental requirements are becoming stricter, and it is necessary to create the retired absorbent processing methods for the further rational use in manufacturing various products and materials. The waste in this research was activated by integrating in 15 % H2O2 aqueous solution, using 20 kHz ultrasonic processing of 200 W powers. Gas-vapor bubbles are formed in the suspension after the treatment with ultrasound.The temperature inside increases to several thousand degrees and the pressure to thousands of atmospheres. Shock waves appear after the collapse of bubbles. The process in the fluid during cavitation helps crushing zeolite particles, facilitates the separation of impurities and accelerates their oxidation reaction. The zeolite sorption capability increases after treatment with ultrasound, especially using ultrasonic treatment in a hydrogen peroxide solution. In this case, the sorption capacity increases about 2.18 times. Thus, the investigated zeolite waste can be used in environmental protection programs for heavy metal sorption.