Study of Malachite Green Adsorption using Tannin-Based Adsorbent (TBA) from Mangrove Bark (Rhizophora mucronata)

Abstract

The growing of industrial activity causes side effects in the form of environmental pollution. One of the causes of environmental pollution is the content of Malachite Green (MG) in wastewater. When consumed, water consists of high MG levels can cause health problems, such as immune system disorders, cancer triggers, and DNA damage, so it is necessary to reduce MG levels before being discharged into the environment. Adsorption is one method to reduce MG levels. One of the raw materials for making adsorbents is mangrove bark, because it contains 20-30% crude tannin, by changing it to Tannin Based Adsorbent (TBA). This study aimed to study the MG waste adsorption using TBA from mangrove bark. In this research, tannin was obtained by extraction using Microwave Assisted Extraction (MAE) method, then it was modified to TBA through a polymerization process using formaldehyde. Analysis using FTIR Spectrophotometer was conducted to confirm the functional groups of TBA and standard tannin. After that the adsorption process is carried out by varying the ratio of the adsorbent mass : waste volume, temperature and adsorption time. MG content analysis was performed using a UV-VIS Spectrophotometer. SEM analysis was done to observe the surface of TBA before and after the adsorption process. The results showed that the highest percent MG removal was achieved at an adsorbent mass ratio: MG volume of 1: 100 gram / mL, adsorption temperature of 60ºC, and adsorption time of 120 minutes.