PENGARUH WAKTU FERMENTASI DAN JENIS RAGI (Saccharomyces cerevisiae Dan Debaryomyces hanseii) TERHADAP PEMBUATAN BIOETANOL DARI SINGKONG KARET (Manihot glaziovii M.A.)

The purpose of this research to prove that cassava peel can be used as raw material for making activated carbon. The cassava peel (Manihot utilissima) hascarbohydrate content 59.31% (Ikawati, 2011). The process of absorption is done by cleaning and drying the cassava peel under sunlight, carbonization, size reduction, and activation with concentrations of activator0,1M, 0,2M, 0,3M, 0,4M, and 0,5M. Then filtered and dried in the oven. Then absorption with the contact time between the adsorbent laboratory wastewater for 24 hours with the variation of the absorbent weight 3gram, 7gram, and 11gram with the activator concentration. The analysis process of the laboratory wastewater includes Fe (Iron), Mn (Manganese), and the levels of COD and BOD. The results of this research show that the optimum absorption of Fe and Mn from the chemical laboratory wastewater occurs in 11 gram of the weight 0,4 M and 0,5 M of the concentration. From the results obtained that cassava peel can be used to absorb Fe and Mn metal content from the chemical laboratory wastewater. Key words: Leather cassava, Activated Carbon, Iron, Manganes