| dc.description.abstract | Onggok is a byproduct of processing tapioca starch industry in the form of solid. Onggok has the characteristics and content of organic compounds are almost equal to one another so that it can represent of all the pretreatment of biomass as a model to determine the level of degradation lignocellulose compounds. Onggok has advantages when compared with other biomass, which is an abundant amount. Conversion of rice to become rice straw in indonesia by 50%, sugar production become bagasse at 40%, while the cassava into onggok by 70% (Retnani, 2010). Onggok are used as the main ingredient of snacks, asia flour, fodder, and flavoring food result modified cellulose that contained therein. Onggok containing lignocellulose compounds or polysaccharides with composition 25% lignin , 25% hemicellulose, and 45% cellulose (Sun and Cheng, 2005). However, the utilization of agricultural waste biomass such as the production of biogas as an alternative energy source is not optimal. Methane gas produced from biomass processing only 4.5 L / kg total solids whereas the theory that gas can be produced up to 180 L / kg total solids. Therefore, there should be the appropriate response to improving biodegradability. One way is to do a pretreatment process to break down the lignocellulose compounds into simple sugars are easy to soluble in water with the help of microorganisms. Some of the microorganisms used in this process is a Saccharomyces sp, Lactobacillus sp, Actinomycetes, Pseudomonas sp, and Aspergillus sp and some elements such as manganese, calcium, magnesium, potassium, and nitrogen as a nutrient. In the mixed inoculums consentration of 5% increase to 2036 mg/l, the concentration of 7.5% increase 2236 mg/l, and the consentration of 10% up to 3167 mg/l. Increasing of COD’s soluble in this process is also followed by reduction in suspended solids. For 16 hours pretreatment onggok, total solids decreased from 15% to 6.12% for a consentration 5%, to 6.1 % for consentration of 7.5%, and 5.9% for consentrations of 10%. The decline of total solids was supported by the decreased of ligniselulosic compound. Comparision of lignin compounds of cellulose decreased from 27% to 11% and hemicellose compound ration of cellulose decreased from 25% to 13% at a consentration of 10% for 16 hours. | en |
