CARBON PASTE ELECTRODE MODIFIED BY ACTIVATED CARBON FROM BAGASSE FOR VOLTAMMETRIC ANALYSIS OF CR(VI) ION

• Main Author: Anggitami, Annisa
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/75176
• Institution: Institut Teknologi Bandung

Heavy metal pollution that is often found in the environment, especially in the aquatic environment, generally comes from industrial waste processing that is not in accordance with the procedures and quality standards applied. Chromium is a heavy metal that pollutes waters and is toxic in the environment, especially in the form of Cr(VI). The existence of industrial development, especially in the electroplating industry which is not balanced by proper waste treatment, can result in environmental pollution, namely in the form of heavy metal contamination from industrial waste which is toxic, such as chromium metal. Due to the toxic nature of Cr(VI) ions, it is necessary to develop a method for analyzing Cr(VI) ions, especially at lower concentration levels. In this study, the voltammetric method was used because it has the advantage of having good sensitivity, wide range of linear regions, fast analysis time, and easy operation. The large number of agricultural by-products, especially in the form of bagasse, can be used as a source of activated carbon which can be used as a modifier that is efficient, effective, at a relatively affordable cost and environmentally friendly. So, in this research a modification of carbon paste electrodes was developed with activated carbon from bagasse which is expected to increase the surface area of the electrodes so as to increase the sensitivity of the carbon paste electrode measurements used. The research stages that have been carried out include activation of bagasse, optimization of electrode manufacture, optimization of electrode measurement techniques, determination of electrode performance, and sample analysis. In this study the activation stage of bagasse was carried out using a furnace reactor, which was heated at a carbonation temperature of 200 °C for 1 hour, then SEM and BET characterization was carried out. Optimization of electrode preparation was carried out by varying the composition of activated graphite:bagasse with variations of 1%, 3%, 5%, 10% and 15% (w/w). Optimization of the measuring technique at the electrodes was carried out using three measurement techniques namely cyclic voltammetry (CV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV) which were measured in a 1 mM Cr(VI) solution containing 0.1 M HCl which was used as a supporting electrolyte. The results of the study were that the optimum conditions for making electrodes were obtained at the composition of graphite: activated bagasse 5% (w/w). The modified carbon paste electrode showed good performance, which was reflected in the results of the repeated test on the electrode with %RSD results of 4.79% for the DPV technique and 3.59% for the SWV technique. The range of the linear area on the electrode using the SWV technique is in the range 1-1000 ?M with a detection limit of 0.5373 ?M. The scan rate analysis shows that the electron transfer is controlled by the adsorption process. Modified carbon paste electrodes have been used to analyze artificial samples. For SEM and BET characterization which shows an increase in the surface area and pore volume of the modifying agent after activation, so as to increase the sensitivity of the EPK. Measurements with the AAS method are used as a comparison method for measurements using the voltammetric method. At the sample analysis stage, statistical tests were carried out with the F test and T test, the results of which showed that there was no significant difference in the measurement results with the two methods used