ADSORPSI LOGAM Cr (VI) MENGGUNAKAN FILM KOMPOSIT CHITOSAN-CLAY DENGAN FIX-BED REAKTOR

Pollution caused by industrial waste is a serious problem that can endanger environmental health. One of the pollutants from industrial processes is heavy metal in the form of Cr (VI). Cr (VI) is a form of chromium that has high toxicity. Therefore, it is necessary to process Cr (VI), one of which is the use of chitosan-clay film as an adsorbent. Chitosan is an adsorbent that is very abundant in nature and is good for use in the adsorption process of some heavy metals but has a high solubility in acidic pH so the utilization of chitosan adsorbent is limited. This study aims to improve the mechanical stability and resistance of the chitosan film by compositing it with clay and to determine the ability of the chitosan-clay film to absorb Cr (VI) metal ions. Before the stability test, the purity of chitosan was tested using Fourier Transform Infrared (FTIR), and the DD value was 80.97% proving the chitosan made had met the standard. The film stability test was carried out by measuring the water absorption (DSA) and tensile strength of the film with various concentrations (2:0.75; 2.5:0.75; 3:0.75) (w/w). Based on the results of the study, the best results were obtained at variations in concentration (3:0.75), namely with a DSA of 142.90% and a tensile strength of 4.434 Mpa. Chitosan-clay adsorbent with the best stability test results was analyzed using the Scanning Electron Microscope (SEM) test to determine the structure and morphology, resulting in a film with larger and homogeneous pores. Furthermore, the adsorbent was applied in the adsorption process using a fixed bed reactor system by varying the concentration of waste 20, 30, and 40 mg/L and sampling time to 0, 15, 30, 45, and 60 minutes. The best metal ion removal efficiency of Cr (VI) was 89.92% with an initial concentration of 40 mg/l to a final concentration of 4.0327 mg/L at 30 minutes.