ENCAPSULATION OF BAMBOO INTO Ca-ALGINATE FOR ADSORPTION OF ION Cd(II)

• Main Author: Murni Harfinda, Elliska
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/32335
• Institution: Institut Teknologi Bandung

Cadmium is used as a component in industrial products, such as Ni-Cd batteries, pigments, coating industries and plastics industries. Cadmium and its compounds can cause damage to lungs, kidneys, liver, prostate and bladder so we need a method for removing cadmium from wastewater before discharge into the environment. According to Indonesia Government Regulation No. 82/2001, the concentration threshold of Cd for all classes of water is not more than 0.01 mg/L. The commonly used methods for removing metal ions include reverse osmosis, electrodialysis, ultrafiltration, ion exchange, precipitation, phytoremediation, and adsorption. The adsorption method is the most widely used because efficient, economical, does not require organic solvents, and can be used in aqueous solution at low metal concentrations. Bamboo is lignocellulosic biomass that can be used as adsorbent. The use of bamboo powder has a problem in the process of separation between the adsorbate and adsorbent after adsorption process when applied to the treatment of wastewater. Therefore, encapsulation bamboo in Ca-alginate is a technique that can be used to overcome this problem. Furthermore, encapsulation also increase the adsorption capacity. Adsorbents were studied in this research are Ca-alginate (CA), protonated Ca-alginate (CAP), and protonated Ca-alginate-bamboo (CABP). The maximum adsorption capacity was 50.90 mg/g, 73.00 mg/g, and 80.02 mg/g respectively for CA, CAP, and CABP at pH 4 with contact time 4 hours. The adsorption process of Cd(II) follows Langmuir isotherm and pseudo second-order kinetics. The FTIR spectra showed that the predominant functional groups involved in the adsorption process are carboxylate groups. This was confirmed by measuring the final pH in the optimization pH where pH after adsorption decreases due to a lot of ions H+ in solution. These protons can be obtained from the carboxylic groups on the alginate off because ion Cd(II) which forms an electrostatic interaction with carboxylate groups. Adsorption of binary systems is performed using ion Cd(II), Zn(II), Cu(II) and Pb(II) shows the adsorbent CA, CAP and CABP not selective. Dynamic studies using a column for CABP with a circulation method indicates 5 hours is the the minimum time required to adsorb all Cd(II) ions from dilute solutions (1 ppm in 250 mL). Desorption ion Cd(II) using 20 mL of 1 M HNO3 solution gives % desorption 104.15% with a preconcentration factor 12.5 times. The performance of CABP was relatively unchanged after three adsorption-desorption cycles. % recovery ion Cd(II) in environmental samples is 56.03% which indicates that the matrix interference causes the adsorption of Cd(II) can not take place properly.