Abstract. The humic liquid is produced from lignite extraction using alkali solution. Conventional humic acid is obtained by acidifying a humic solution using HCl. The purpose of this research is the formation of solid humic acid from lignite by ion exchange method using cation resin. The results showed that the addition of cation resin was able to reduce the pH from 14 to pH 2 as well as the addition of acid (HCl), indicating the exchange of Na + ions with H + ions. The reduction of pH in the humic solution is influenced by the concentration of sodium ions in the humic solution, the weight of the cation resin, and the ion exchange time. The IR spectra results are in good agreement for humic acid from lignite characterization.

Food Safety sistem is a method that commonly use to guarantee the quality of food product in order to avoid hazard which can causing harm to the consumer. One of the well-known traditional food, Tempe, which is made from fermented soybean, has consumed by most of people in Indonesia. Tempe has a short shelf life. The aim of processing Tempe are to make the shelf life longer and also to diversify product of Tempe. One of the most popular product of Tempe is Tempe cracker. Parerejo village is well-known as one of the Tempe and Tempe cracker production base in East Java. Unfortunately, its production has not yet applied Food Safety Sistem. Some actions were needed in order to improve the knowledge of the Tempe and Tempe cracker producers about Food Safety Sistem. Firstly, questionnaires were distributed to the Tempe and Tempe Cracker producers in Parerejo village to determine the level of community understanding about Food Safety Sistem. After distributing the questionnaires, the next action was presenting of the definition, the aspects and the importance of implementation Food Safety Sistem in the production process of Tempe and Tempe cracker. Questionnaires showed that most of the producers of Tempe and Tempe crackers in Parerejo village realizes the importance of implementation Food Safety Sistem. In other hand, Food Safety Sistem has some obstacles to fully apply in the production process. The biggest challenge is the production facilities. Improving sanitation sistems such as sanitation of workers and equipment is one of the real efforts that can be done to improve the production sistem. Sortation of raw material also an effort to avoid physical hazard that can causing harm of the product. At least, awareness of the community about Food Safety Sistem have improved and committed to do some correction in order to avoid the hazard in production process.

This research was carried out to produce precipitated silica from sodium silicate using acidic salt as precipitator. The aim of this research is to study the effects of acidic acid on precipitated silica characterization. The sodium silicate solution was produced by extraction of geothermal sludge using sodium hydroxide 2N solution. Precipitated silica products were characterized by x-ray diffraction, x-ray fluorescence and scanning electron microscopy. The results showed that the silica precipitated prepared by aluminum sulfate solution (1-3N) is a silica-alumina composite, amorphous structure and about 0.5 millimicron particle size. Precipitated silica with a concentration of 91-99 %SiO2 can be produced from sodium silicate solution using 1-3N sodium dihydrogenphospate solutions, have an amorphous structure and 1-2 millimicron particle size. Microscopically precipitated silica prepared by aluminum sulfate has a softer structure than that of precipitated silica prepared by sodium dihydrogen phosphate.

Trass rock is a rock originating from volcanic eruption materials which has experienced weathering. It has the similar composition as bentonite. Therefore, trass rock can also be used as raw material as a bleaching earth to substitute bentonite. In this study, a two-stage process was conducted: to do the activation process of trass rock and stage bleaching process of palm oil (CPO). In activation process, trass rock was performed by using hydrochloric acid, then trass rock was crushed until it could pass of the 200 mesh. After that, the soft rock was weighed and added to the acid solution with the ratio of: 1 : 10 with the concentration of hydrochloric acid solution 5 N and its activation time was 4 hours at the temperature of 105 0 C. Meanwhile, for the bleaching process, at first, oil was treated with degumming and netralization process. Furthermore, oil bleaching process was carried out by adding the activated trass . Then trass was put into the oil when its temperature was reaching up to 186 0 C. Heating was continued until its temperature was reaching up to 198 o C for 45 minutes. In this activation process, it was obtained that the content of SiO2 was 37.8%, Al2O3 of 4.4% and the ratio of SiO2/Al2O3 is 8.6. In the bleaching process of palm oil (CPO), the best condition of trass addition was 4% of the oil weight, and its bleaching time was 45 minutes, the red color intensity obtained was 6.9 and yellow was 6.1, with FFA as big as 2.13% and peroxide value was 5.45 meq/kg.