Pembuatan Adsorben dengan Menggunakan Campuran Tanah Bentonit yang Teraktivasi Asam Sulfat Dan Zeolit Sintetik dari Abu Sekam Padi untuk Menurunkan Kadar Mangan (Mn) pada Air

Abstract

Rapid population growth in Indonesia, especially in big cities, will drive housing needs and meet the need for clean water. Groundwater contains pollutant metals including Mn. Water containing excess manganese (Mn) will cause color (brown/purple/black) and turbidity, so further processing is needed so that the water can be used for domestic purposes. The use of surface water is also increasing in society, but metal content removal technology is needed so that water can be used. One possible technique for removing metal content is the adsorption process using zeolite and bentonite adsorbents. This study aims to remove manganese metal (Mn) from artificial groundwater under adsorption conditions using a batch method and continuous column with a mixture of synthetic zeolite adsorbents of rice husk ash and sulfuric acid activated bentonite as adsorbents. In this study, variations were made on the ratio of the zeolite-bentonite mixture and the contact time during the adsorption treatment. The adsorption process was carried out using batch and continuous column methods. Artificial groundwater that has been adsorbed will be analyzed with an Atomic Absorption Spectrophotometer (AAS) to see the Mn content after adsorption. The adsorption process using the batch method used a sample of 200 ml of artificial groundwater which would be adsorbed with a mixture of zeolite-bentonite adsorbents with a ratio of 1:1; 1:2 and 1:3, time: 5, 10, 15, 30, 45, 60, 90, 120, 150 and 180 minutes and stirring speed 0, 50, 100 and 150 rpm. Whereas the continuous column method was carried out by flowing 1000 ml of artificial groundwater in a continuous column with a kontinu height of 5 cm and 5 g of adsorbent mass and contact times of 15, 30, 45, 60, 120, 180, 240 and 300 minutes. From the results of the SEM-EDS analysis, the characteristics of the zeolite-bentonite mixture using the H2SO4 activator can be seen that the surface of the zeolite-bentonite becomes rough and many cracks form which indicate an increase in surface area due to activation. From the research using the batch method, the best zeolite-bentonite mixture ratio was obtained, namely 1:3 with a contact time of 120 minutes and a stirring speed of 150 rpm, the Mn content was 0.3569 mg/L with a percent removal of 85.60%. Where, the amount of bentonite is more than zeolite. In the adsorption process using a column, the best zeolite bentonite ratio is 1:3 with a contact time of 15 minutes and a Mn content of 0.0097 mg/L, the largest adsorption capacity is 0.4903 mg/g and the lowest Ct/Co ratio value is 0.0194 mg/mL which means the longest saturation time is reached in the conditions and the adsorbent mixture. The kinetic model selected for the zeolite-bentonite adsorbent in the batch method with a 1:3 ratio of Mn removal is pseudo second order with an R2 value of 0.9993 and in the continuous column method using the thomas kinetics model the R2 value is 0.9087. Overall the results of the study prove that the use of a mixture of synthetic zeolite adsorbents of rice husk ash and sulfuric acid activated bentonite using the batch and column method has the potential to remove metals from groundwater