The objective of this research is to study the adsorption of cromium and nickel from synthetic wastewater by activated carbon from Eucalyptus (Eucalyptus camaldulensis Dehnh.) and Acacia (Acacia mangium Willd.). The chemical activated process was sodium chloride. In the activated carbon preparation process, the results showed that the temperature suitable for carbonization of the raw material was 300 degree Celsiuses at 120 minutes, which gave the heighest yield percent at 59.01 % and 60.91 % for both charcoal materials respectively. The appropriate ratio by weight of charcoal material to sodium chloride was 1:2 for both activated carbon at temperature 800 degree Celsiuses for 1 hour, which gave the heighest iodine number at 612 and 701 milligrams per gram respectively. The activated carbon from eucalyptus and acacia had surface area 368.68 and 408.64 meters square, pore volume 0.27 and 0.34 centimeters cubic, average pore size 13.55 and 18.04 A[superscript 0] respectively. Freundlich adsorption isotherm, it was found that K value of activated carbon from eucalyptus acacia and Calgon Filtrasorb 300, at pH 9 can adsorbed cromium 1.36, 12.57 and 24.64 milligram per gram and nickel for 38.24, 50.31 and 217.99 milligram per gram respectively. In adsorption column test, activated carbon from acacia was used for packing in the column. The result showed that activated carbon can treated cromium from synthetic wastewater for 82.34, 52.94, 43.14 and 41.18 BV with 10 milligrams per liter of cromium influent concentration respectively and at depth of adsorbent 30, 60, 90 and 120 centimeters of column test, activated carbon from acacia can treated nickel from synthetic wastewater for 129.41, 70.59, 50.98 abd 50.00 BV with 10 milligrams per liter of nickel influent concentration respectively. For activated carbon regeneration studies, by using 5% by weight of hydrochloric acid as a regenerant it found that the iodine number of activated carbon value was 388 and 421 milligram per gram on cromium and nickel adsorption respectively.
