| dc.description.abstract | Spend coffee grounds are biomass waste that has a high adsorption capacity, in this
study used coffee grounds were used as adsorbents in adsorbing chromium metal
in aqueous solutions. The coffee grounds were first activated using inorganic
solvents such as H2SO4, HNO3, and HBr with ratios of activator to adsorbent of 1:4,
1:5, and 1:6 g/ml and were activated for 1, 2 and 3 hours. This activation process
was carried out to examine the effect of the activation process on the spend coffee
grounds adsorbent. In the activation process, the adsorbent which has a higher
removal percentage will then go through an adsorption process, this is done to
determine the best adsorbent which is activated using organic acids in the activation
process. In the adsorption process, the pH of the chromium solution was varied
1,2,3,4 and 5 with contact times of 60, 80, 100, 120 and 140 minutes and using a
concentration of chromium solution of 20,50,80,110 and 140 g/ml. Used coffee
grounds adsorbent which has gone through the activation process and then analyzed
by Iodine Number Analysis, Atomic Spectrocopy Adsorption Analysis (AAS),
Scanning Electron Microscope (SEM) Analysis, and Fourier Transfor Infra-Red
(FTIR) Analysis. From the results of the analysis, it is known that the adsorbent
activated with H2SO4 and HNO3 solvents with a ratio of 1:6 for 3 hours and the use
of HBr solvents with a ratio of 1:6 for 1 hour were the best operating conditions for
the activator, with each chromium removal percentage of 90. .50%, 88.92%, and
85.42%. The best operating condition in the adsorption process was the adsorbent
activated with H2SO4 solvent with a concentration of 20 g/ml chromium solution at
pH 4 with a contact time of 120 minutes resulting in an adsorption efficiency of
90.50%. | en_US |
