THE EFFECT OF ADSORBENT AGENTS: SILICA, ANDISOL, LECA, ANTHRACITE, AND ACTIVATED CARBON ON POLLUTANT UPTAKE IN THE CITARUM RIVER (Pengaruh agen penjerap silika, andisol, LECA, antrasit, dan karbon aktif terhadap penjerapan polutan di Sungai Citarum)

Citarum is the longest and largest river in West Java-Indonesia which plays a critical role in the water supply. Water treatment is needed to process the Citarum water due to its  pollutants have been over standard for human consumption. Nowadays, the adsorption process is still popular in water treatment process because of its effectiveness. In this study, the effectivity of five adsorbents on Citarum water treatment: silica, andisol, LECA (Light Expanded Clay Aggregate), anthracite, and activated carbon has been evaluated with variable contact time and solid loading. After treatment, turbidity and heavy metal of filtrate were analyzed. Surface characteristics, functional group, and surface area of five adsorbents were done by FE-SEM (Field Emission - Scanning Electron Microscopes), FTIR (Fourier Transform Infrared Spectroscopy), and BET (Brunauer-Emmett-Teller) surface area analysis, respectively. The result showed that  andisol and LECA decreased turbidity of Citarum water from 21.3 NTU(Nephelometric Turbidity Unit) to 1.23 and 2.52 NTU after 10 min contact time. Activated carbon was taking another 10 min longer to decrease turbidity to 2.26 NTU yet it has the highest surface area, 548.310 (m 2 /g). Surface area was in correlation with FE-SEM result where activated carbon has a more regular and larger pore size compared to others adsorbent. In general, andisol, LECA, activated carbon were successful to decrease turbidity of Citarum water which correlated to their paricles’ surface area.