Judul: Karakterisasi Pertumbuhan Mikroalga dan Eliminasi Nutrien dari Limbah Cair Peternakan dengan Sistem Semi Kontinu
Abstrak: One way of wastewater treatment is a biological process with the help of a combination of microorganism such as bacteria and microalgae. Degradation organic content of waste water by bacteria and then the result of degradation by bacteria in the form of nitrate and CO2 utilized by microalgae. Microalgae also produce O2 as a result of photosynthetic bacteria that can be used. The growth of microalgae is very closely related to the availability of macro and micro nutrients as well as influenced by environmental conditions. Microalgae needed nutrients consist of macro nutrients (N, P, K, S, Fe, Mg, Si and Ca) and micro nutrients (Mn, Zn, Co, Bo, Mo, B, Cu, etc. ). Environmental factors that influence the growth of microalgae, including light, temperature, water pH, and salinity. The purpose of this research to know microalgae growth caracterization in wastewater cattle breeding and to know nutrient eliminate caracterization from wastewater cattle breeding on microalgae cultivation with semi-continuous system. In this research, microalgae was cultivated, using microalgae inoculum from Lake LSI IPB and use wastewater of cattle breeding from MT Farm Ciampea. Pretreatment wastewater used aerator in a tank for five weeks. The purpose of this pretreatment to reduce odor generated liquid waste and reduce organic matter content. In a preliminary study done by two microalgae cultivation treatments on the vessel I (75% wastewater: 25% inoculum microalgae) and the vessel II (50% wastewater: 50% inoculum microalgae). Techniques of microalgae culture has done semi continuous. Harvesting was conducted periodically, and the addition of nutrients to the volume culture as much as the amount have harvested. Of the two treatment obtained a preliminary study of the best cultivation method is in the vessel I, where the abundance of microalgae were compared with the second vessel. At the main study by using waste ratio 75%: 25% visible microalgae abundance of microalgae in the early experiments of H-12 and the harvesting of 25% with semi-continuous system, and the H-16 was again semi-continuous harvesting system as well as 75%. From this treatment more quickly visible growth after harvesting microalgae microalgae as much as 75%, because the waste was added too many (75% = proportional to that harvested). In the first experiment with detention time of 12 days nitrogen concentration was decreased 5.79%, orthophosphate concentration was decreased 0.34%, and COD concentration was decreased 75%. In the second experiment with two days detention time nitrogen concentration was decreased 0.63%, orthophosphate concentration was decreased 0.15%, and COD concentration was decreased 33%. In the third experiment with detention time of 6 days the nitrogen concentration was decreased 3.14%, orthophosphate concentration was decreased 0.42%, and COD concentration was decreased 78%. Harvesting with the test results of TSS in H-12 abundance of microalgae in 2135 mg / L. Microalgae are good for handling wastewater has a high nutrient content. In addition nutrient content that have contained in mediakultivasi, light, temperature and pH are important factors also in microalgae cultivation. To enhance the ability of microalgae to eliminate the nutrient contained in the wastewater, waste volume ratio must be greater than the volume of microalgae.
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Judul: Karakterisasi Pertumbuhan Mikroalga dan Penyisihan Nutrien dari Limbah Cair Rumah Pemotongan Hewan dengan Sistem Kultur Semi Kontinu
Abstrak: Organic wastewater with high nutrient content can stimulate uncontrolled microalgae growth. Whereas discipline control led growth can be very profitable. The research was performed to determine the characteristic of growth microalgae nutrient elimination from slaughterhouse wastewater in semi continuous culture system with 75% concentration of slaughterhouse wastewater : 25% consortium of microalgae. In addition, the separation and harvesting of microalgae for the known oil content was also investigated. Cultivation of microalgae has been done at a temperature and pH of the field approach, then temperature and pH dependent on state in the field daily. The light source is obtained directly from the sun. Circulation in a semi continuous culture media which have been made simply by aeration when sampling. Microalgae consortium cell density attained 640 000 cell/ml. During the cultivation for 18 days, the growth of Chlorella sp dominate the culture, that follow by growth of Euglena on day 20 after the death phase of Chlorella sp through. The best growth of Chlorella sp (on day-12) occurred with a concentration of nutrients containing: 1 mg/l for N-organic content, 1 mg/l for NNH3, 4 mg/l for N-NO3 - then total of nitrogen 6 mg/l, orthophosphate content of 10 mg/l, and potassium values of 87.5 mg/l with consortium cell density attained 3 130 000 cell/ml and TSS Filtration 1 930 mg/l. Convertion of biomass from TSS with amount of nitrogen or TKN (on day 2 until 12) is 180 mg TSS/ mg TKN and convertion of biomass from TSS with orthophosphate content in the same time is 4 200 mg TSS/ mg Orthophosphate. Maximum population of microalgae decrease due to lower nutrient content in culture media. Although the consortium of microalgae dominated by Chlorella sp, oil content (3.03%) and oil productivity is 3 000 liter/ha/year still low compared with a previous study, that have been in research by Hsieh and Wu (2009), Widjaja (2009) along with Danusubrata (2010). It was caused by nutrient treatment which have not yet optimum.
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Judul: Grup dan Homomorfisma Grup pada Rubik Revenge
Abstrak: Rubik cube is a kind of puzzle game. A player must arrange rubik sides, which have been disordered, back to the position where every side has the same colour. This paper does not focus on the settlement solution, but instead on proving the existence of a group homomorphism between rubik movement group and S96 symmetric permutation group in rubik revenge. Firstly, it has been proved that rubik movement set is a group. Then, it also has been proved that the M set, which contains numeric labels of 1 until 96 in cubinos sides, is S96 symmetric permutation group.
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