KINETICS AND ADSORPTION CAPACITY STUDY OF MANGANESE AND IRON IONS ONTO MORDENITE MINERAL ADSORBENT USING BATCH SYSTEM

• Main Author: Novandy, Deify
• Format: Theses
• Language: Indonesia
• Subjects: Teknik saniter dan perkotaan; teknik perlindungan lingkungan
• Online Access: https://digilib.itb.ac.id/gdl/view/32066
• Institution: Institut Teknologi Bandung

As a country with natural rocks and minerals, groundwater in Indonesia especially in Bandung, contain high levels of metal ions (iron and manganese ions). Metal removal in water using filtering techniques (filtration) was mostly done with zeolite as filtration media. Natural green Sukabumi stone, West Java, is one of the mordenite mineral resources that can be used as a filtration media. Cutting waste of green Sukabumi stone were expected become a useful material in water treatment process. Ability of natural mordenite green Sukabumi stone to adsorb iron and manganese ions was studied in this research. The experimental data followed the kinetics model of pseudo second order. Pseudo second order model indicated that chemical process as an adsorption rate controller. Initial rate adsorption using activated mordenite was higher than natural mordenite which increase from 0.013 mg/g.min to 0.034 mg/g.min for iron adsorption and 0.033 mg/g.min to 0.047 mg/g.min for manganese adsorption. For isoterm study of manganese and iron ions, the data fit well to the Freundlich isotherm models. Freundlich parameter (1/n) showed the adsorption driving force and energy site distribution onto adsorbent. Freundlich parameter (1/n) value is smaller than 1 showed the heterogent adsorption surface and adsorption occurs as a physical process. Beside that, KF value as capacity indicator was higher by using activated mordenite. Increasing of KF value for iron adsorption using activated mordenite did not give significant differences which increase from 0.204 mg/g to 0.125 mg/g compare to manganese adsorption increase from 0.1857 mg/g to 0.378 mg/g. It showed that manganese adsorption using activated mordenite was higher. Both of the kinetics and isoterm test results indicated that activation process able to increase the adsorption capacity of iron and manganese ions, particularly manganese ion. By varying the solution multicomponet (iron and manganese), iron presence in water will reduce manganese adsorption capacity using natural mordenite. At equilibrium point (30th minute), using lower manganese concentration than iron, iron adsorption capacity decrease 11.4% for natural mordenite and 14.7 % for activated mordenite. At higher concentration of manganese, iron adsorption capacity decrease 19.7% for natural mordenite and 14.3% for activated mordenite. Similar to iron presence in water will decrease adsorption capacity of manganese using natural mordenite. At equilibrium point (30th minute), using lower iron concentration than manganese, manganese adsorption capacity decrease 2.45%. When using higher iron concentration, manganese adsorption capacity decrease 28.75%. Contrast to the use of activated mordenite to reduce mangenese ions, presence of iron in water did not give some effect for manganese adsorption onto activated mordenite. Variations of iron concentration in water (higher or lower) than manganese concentration did not give significant effect to adsorption capacity value of manganese. At equilibrium point (30th minute), whether single or multicomponent solution, adsorption capacity of manganese showed the same value. Thermodinamics results showed the Gibbs free energy (?????0). Comparing ?????0 value between iron and manganes adsorption, activated mordenite give a higher ?????0 value for iron adsorption from -4,715 kJ/mol to -8,723 kJ/mol than manganese adsorption from -3.036 kJ/mol to -4.496 kJ/mol. A higher value indicated that energy needed for iron adsorption using activated mordenite was higher. ?????0 value from -20 kJ/mol to 0 kJ/mol informed that adsorption occurs physical mechanism. From kinetics, isoterm, and themodinamics results, iron and manganese sorption process onto natural and activated mordenite occurs through 2 mechanism, physical process (electrostatics) followed by chemical process (ion exchange and complex coumpound forming).