Hanifrahmawan Sudibyo

The effect of natural zeolite as microbial immobilization media in anaerobic digestion at various concentrations of palm oil mill effluent (POME)

Anaerobic digestion is one of the solutions in POME treatment because it generates energy in the form of biogas. Nevertheless, high concentration of POME fed into the digester will cause high acidification level and eventually cause process failure. The failure can also be affected by high inhibitor concentration contained in POME, one of which is long chain fatty acid. The addition of immobilization media is commonly used to increase the bacteria resistance to inhibitor. Natural zeolite is considered as appropriate immobilization media for waste treatment purpose since it is cheap, has high mechanical strength, high immobilization capacity, and its ability as cation exchanger. The digested biodiesel waste was used as starter inoculum for its good capability in digesting oil-containing feed such as POME. This research was conducted to evaluate critical concentration of POME fed to digester where the natural zeolite could not reduce the inhibitory effect. The concentrations of POME evaluated were 10,000 mg...

Assessment of start-up mechanisms for anaerobic fluidized bed reactor in series based on mathematical simulation

Anaerobic digestion is associated with long hydraulic residence time and hence leads to huge reactor volume, especially for high rate input to the reactor. To overcome this major drawback, one of the possibilities is optimizing the schemes of reactor configuration and start-up mechanisms. This study aimed to determine the most promising start-up mechanism for anaerobic digestion reactors in series, with respect to the shortest hydraulic residence time to reach the highest biogas production rate. The reactor to be studied is anaerobic fluidized bed reactor (AFBR) which is known as the most efficient reactor for high organic loading rate. Case to be studied is landfill leachate digestion. Although reactor optimization can be conducted experimentally, it could be expensive and time consuming. This study proposed the utilization of mathematical modeling to screen the possibilities towards the best options to be verified experimentally. Kinetic study of landfill leachate anaerobic digestion was first conducted...

Bio-Synthesis of Eicosapentaenoic Acid (EPA) from Palm Oil Mill Effluent Using Anaerobic Process

The supply of omega-3 fatty acids, which are EPA and DHA, was only 14.7% of the prospective demand calculated by using 500 mg/day/person as threshold limit for EPA and DHA consumption for a world population of 7.515 billion people. Alternative sources other than fish oil or seed-based-α linolenic acid (ALA) were necessary. Anaerobic digestion of palm oil mill effluent (POME) offered a new way for one of omega-3 fatty acids production, EPA. The digestion was conducted in anaerobic fluidized bed reactor supported by natural zeolite as the immobilization media. Process condition tried to be optimized was the pH level and the pre-treatment method (TSS filtration) before the digestion. Without any pre-treatment, the fatty acid profile produced after digestion contained considerable amount of polyunsaturated fatty acid with acidic condition provided higher EPA purity. On the other hand, pre-treatment led the digestion to produce saturated fatty acids with acidic condition provided very high purity of butyric acid as the product.

Anaerobic treatment of palm oil mill effluent in batch reactor with digested biodiesel waste as starter and natural zeolite for microbial immobilization

Palm oil mill effluent (POME) is the wastewater discharged from sludge separation, sterilization, and clarification process of palm oil industries. Each ton of palm oil produces about half ton of high organic load wastewater. Up to now, POME treatment is done in lagoon, leaving major problems in land requirement and greenhouse gasses release. The increasing of palm oil production provokes the urgency of appropriate technology application in treating POME to prevent the greenhouse gasses emission while exploit POME as renewable energy source. The purposes of this study were firstly to test the effectiveness of using the digested biodiesel waste as the inoculum and secondly to evaluate the effectiveness of natural zeolite addition in minimizing the inhibitory effect in digesting POME. It was expected that the oil-degrading bacteria in the inoculum would shorten the adaptation period in digesting POME. Furthermore, the consortium formation of anaerobic bacteria accelerated by natural zeolite powder addition ...

Anaerobic digestion of palm oil mill effluent with lampung natural zeolite as microbe immobilization medium and digested cow manure as starter

Indonesia is well-known as the world’s biggest palm oil producer with 32.5 million tons of annual production. Palm oil processing contributes to 60% wastewater, leading to environmental problem caused by excessive production of wastewater. This wastewater, i.e. Palm Oil Mill Effluent (POME), has high organic content (40,000-60,000 mg COD/L) which is potential for biogas production. However, its low pH value and long chain fatty acid content likely inhibit the anaerobic digestion. Porous media might reduce the inhibitory effect during POME digestion since the media act as both immobilization media for bacteria and as inhibitor adsorbent. Excessive amount of porous media might interfere with the nutrient consumption by microbes. There will be an optimum amount of porous media added, which depends on the wastewater characteristics. This research studied Lampung natural zeolite as immobilization media in digesting POME. The batch experiment was conducted for 40 days with different amount of natural zeolite, i...

Simultaneous Hydrolysis and Fermentation of Sweet Sorghum Varieties (FS501 and KCS105) into Bioethanol Using Saccharomyces steineri – A Kinetics Study

In this study, kinetics of bioethanol production by fermentation of three different substrates, which were artificial substrate and the juice of two sweet sorghum varieties (FS501 and KCS105) using Saccharomyces steineri, were examined using two proposed models by assuming that simultaneous hydrolysis and fermentation occurred. Fermentation of the substrate of FS501 and KCS105 juices showed better data fitting by using the modified version of the kinetics model while the fermentation of artificial substrate which was free of any other components followed Philippidis’s kinetics model. This difference was caused by the change of the yeast behavior in the form of the reduction of both the rate of fructose and/or glucose consumption by the yeast and the rate of fructose and or glucose conversion into ethanol during lag phase. As the consequence, sucrose hydrolysis seems very dominant in the FS501 and KCS105 juices fermentation during the lag phase. The change of behavior of the yeast was estimated being caused by the existence of “impurities” such as acetic acid, glycerol, nitrogen, phosphor, and potassium in the FS501 and KCS105 juices. From statistical analysis using correlation coefficient (between kinetics parameters and “impurities”), acetic acid was the most influential component to change the behavior.