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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