RICE HUSK ASH FOR BINDING MERCURY IN THE WASTE OF TRADITIONAL GOLD MINING IN NORTH SULAWESI

This study was done in order to find out how the ash of rice husk able to bind mercury. The ability is related to time and the weight of husk needed to bind mercury contained in gold mining waste. The study uses an experimental method, with two factors of Completely Randomized Design. The first factor was the weight of rice husk (M), consists of 3 groups of treatment: 300 g (M1); 600 g (M2); and 900 g (M3). The second factor was the length of immersion time (T), consists of 4 groups of treatment: 0 (T1); 30 (T2); 60 (T3); and 90 minutes (T4), each of 3 replications. Procedure of research consists of two stages: firstly to describes the initial effluent from the traditional gold processing; and secondly to remediates the waste using rice husk ash. Analyses of mercury before and after treatment were done using atomic absorption spectrophotometer. The results showed that rice husk ash can bind mercury in traditional gold mining waste. The best treatment is the M3T3 or husk ash weight of 900 g and length of 90-minute treatment in which the content of mercury is 0.00006 mg.l-1 while the control or the results of the initial description is 0.0041 mg.l-1. Both the weight of rice husk ash and the length of immersion time significantly affect the binding of mercury (p> 0.05) thereby reducing the mercury content in traditional gold mining waste in the Tatelu Village, Dimembe Subdistrict, North-Minahasa Regency, North-Sulawesi Province, Indonesia.