Oleh: Agus Taufiq, Ahmad Zakaria (Akademi Kimia Analisis Bogor)
Coal contains high carbon, thus ir is not only potential for fuel, but also can be used as an adsorbent for heavy metal transition, such as mercury. Mercury contaminated wastewater produced in great quantities from electroplating industries, battery and gold mining and shows acute toxicity toward the environment. The objective of this research is to explore characteristics of kinetic adsorption of Hg2+ on solution system using acid activated coal adsorbent. Various adsorbate concentration, contact time, and agitation speed used on this research. The result of this research revealed that efficiency of Hg2+ ion adsorption by activated coal adsorbent influenced by contact time and agitation speed. Efficiency decreased with increase in adsorbate concentration. 100 ug/l adsorbate concentration gave efficiency of 93,1%, whereas at 2000 ug/L adsorbate efficiency reduced to 76,8%. At contact time range from 15 to 75 minutes efficiency increased from 77,1% to 81,3%, whereas increasing efficiency from 68,1% to 75,2% was resulted when agitation speed increased from 50 rpm to 300 rpm. Based on metal Hg2+ adsorption by activated coal at various initial concentration, this adsorption followed Langmuir isotherm equation with correlation coefficient of 0,9320 with maximum adsorption capacity (Qo) of 1000 ug/g.
Key words : acid activated coal adsorbent, adsorption, Hg2+ ion