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In Indonesia, Hospital wastewater treatment generally use biological process followed by chlorination process. Chlorination process has a negative impact on the aquatic environment that is cause death of other microorganisms by the residual chlorine. On the other hand, ozone is more effective than chlorine in killing microorganisms and other pollutants in hospital wastewater. The objective of research is to determine the effect of contact time and dose of ozone to reduction of pollutants (BOD, COD, free Ammonia and Phenol) in hospital wastewater. The experiment was carried out using an ozone reactor containing 'packing', an ozone generator as an ozone gas supplier. The experimental material is a hospital wastewater containing BOD, COD, Phenol and Ammonia free. The experimental variables used were: Contact time (1, 2, and 3 min), Dose of ozone (10, 15, and 20 mg/ L). Experiments were done by flowing hospital waste water at the top of the reactor ozone at certain rate and simultaneously flowed ozone gas from an ozone generator in the bottom of the ozone reactor so that it contacts the fluid in counter-current to the surface of the packing material (packing) in an ozone reactor. By adjusting the flowrate of the wastewater and the height of the packing, it can be determined the amount of contact time and ozone dose. Furthermore, by measuring the amount of pollutant concentration on the influent and effluent of the ozone reactor, it can be obtained the amount of removal in the pollutant concentration of the hospital wastewater. The results showed that contact time and ozone dose influence the decrease of pollutant concentration in hospital wastewater where contact time at 3 minutes and ozone dose 20 mg/L and ozonation time 15 minutes can reduce of pollutants concentration as BOD (97%), COD (98%), Ammonia free (97%), and Phenol (96%).

BOD, COD, phenol and ammonia-free in the effluent of hospitals wastewater often exceed the quality standards. This was due to less optimal biological processes to degrade the pollutants. So we need an efforts to find optimal process conditions through the engineering process and the factors that affect the biodegradation of pollutants. On the other hand, AF2B reactor containing biofilter with bee nest shaped has a large specific surface area so as to maximize the biodegradation process of pollutants by microorganisms. While bacteria consortium consisting of several types of bacteria have a greater capacity than a single bacterium in the degradation of pollutants. The research aims to determine the effect of starter volume and air flowrate to decrease the concentration of pollutants (BOD, COD, phenol and ammonia-free) in AF2B reactor batch using a bacterial consortium. The research was conducted in three phase which are the making of growth curve, acclimatization and biodegradation of pollutants in an AF2B reactor batch using a bacterial consortium. The experiment variables are the starter volume (85%, 75%, 65% in volume), and the air flowrate (2.5; 5; and 7.5 liter/min). Materials used are hospital waste water and bacterial consortium. The experiment begins with setting up the AF2B reactor containing biofilter with bee nest shaped and then filled it with a starter from the acclimatization process on a given volume and followed by supplies of air at a certain flowrate. Then hospital waste water and 5% of nutrients were added till reach 10 liters of total volume in reactor. Samples were taken every 30 minutes for up to 360 minutes of biodegradation process. The samples were then analyzed its pollutants concentration (BOD, COD, phenol and ammonia-free). The BOD concentration was analyzed using Winkler bottles method, COD using open reflux method, while phenol and ammonia-free using UV-Vis spectrophotometry method. The results showed that the starter volume and air flowrate affect the decrease of pollutants concentration till reach quality standard, which at starter volume of 85%, air flowrate of 7.5 liter/min and biodegradation time of 360 min can reduce the BOD, COD, phenol, and ammonia-free to 92%, 86%, 88% and 76% respectively.

Coconut oil combustion characteristic is observed experimentally by evaporating oil in the boiler then mix it with air before being burned at various equivalence ratios in the Hele-shaw cell. The result shows that, coconut oil tends to break into glycerol and fatty acid due to hydrolysis reaction producing the flame propagation, where the fatty acid flame propagates first then glycerol flame. Micro-explosion occurs when moisture from fatty acid combustion is absorbed by glycerol and higher heating due to higher flame speed produces more micro-explosion.