Effect of weight and contact time adsorption of activated carbon from coal as adsorbent of Cu(II) and Fe(II) in liquid solutions

Experiments have been done for preparation activated carbon with low-rank coal as raw materials taken from PT. Bukit AsamTanjungEnim, Mining unit in South Sumatra, Bangko mining site. This research aims to apply coal activated carbon as an adsorbent for heavy metals Cu (II) and Fe (II) in solution. Chemical activated uses 40% ZnCl2 with 60% coal at 28 mesh, and carbonization was carried out at a temperature of 500°C for 2 hours. Preparation activated carbon from coal aims to see its potential as a metal adsorbent in a liquid solution. The activated carbon was distinguished by iodine number and nitrogen adsorption BET. The iodine number was 1,393 mg/g, the surface area of this activated carbon is 512 m2/g with a pore volume of 0.297 mL/g and pore diameter of 11.5Å. The low-rank coal activated carbon was used for the adsorption of Cu(II) and Fe(II) ions by using variations in the weight of activated carbon 600, 900, 1,800, 2,400 and 3,000 grams and variations in contact time 3, 6, 9, 12 and 15 hours. The results showed that a maximum removal percentage for Cu(II) 99.88% was obtained for 3,000 grams of activated carbon with a contact time of 15 hours, and maximum removal percentage for Fe(II) 96.24% was obtained for 3,000 grams of activated carbon and 12 hours of contact time. The study produced micropore activated carbon with a large surface area and effectiveness for metals removal. Based on Freundlich isotherm, obtained that adsorption capacity of Cu(II) and Fe(II) were 1.967 and 1.829 mg/g. Based on Langmuir isotherm, obtained that adsorption capacity of Cu(II) and Fe(II) were 0.6277 and 0.955 mg/g.