Budiyono Budiyono

Rice husk is a biomass that can potentially be converted into biogas energy. In this research, a study was carried out regarding the effect of alkaline pretreatment and then a study related to the potential for developing biogas from rice husks in Indonesia and a study related to the potential utilization of biogas by-products in the form of slurry as solid organic fertilizer. So, the main objective is to determine the effect of alkaline pretreatment of rice husks on the potential development of rice husks as raw material for biogas production on a full-scale anaerobic digestion (AD). Research related to the effect of alkaline pretreatment using 3% NaOH by immersion in the substrate for 24 hours was carried out on a lab scale. The variable TS is set at 27%, C/N ratio is 35, uses a 2-liter digester, and measurements are carried out every other day for 60 days. Furthermore, the up-scale was carried out with an AD fixed dome model with a volume of 6 m3. In this study, it was found that pre-treatment with 3% NaOH increased biogas productivity by 1.6 times higher. The potential for rice husk to be converted into biogas energy can reach 3.5 million liters of biogas by 2022. The by-product of biogas in the form of slurry also has the potential to be used as solid organic fertilizer directly. Parameter tests that have been carried out show that the slurry in biogas from rice husks that have gone through a 60-day AD fermentation process complies with the Indonesian National Standard (SNI) 7763:2018 concerning solid organic fertilizers.

The increasing lack of clean water has created a paradigm for treating wastewater directly from the source. This study aimed to determine the effectiveness of processing domestic waste using plastic bottle caps in the anaerobe and aerobe reactor system by measuring several key parameters in wastewater. Experimental study on on-site wastewater treatment system using two bioreactors, a biodegradation made from fruit and vegetable peel waste, and local microorganisms. Domestic wastewater was used in this study. The wastewater treatment system's performance was monitored using parameters like pH, temperature, total suspended solids (TSS), chemical oxygen demand (COD), and biochemical oxygen demand (BOD), collected daily at 9 am during peak wastewater generation. The wastewater treatment system using aerobe and anaerobic reactors with plastic bottle cap media and microorganism biodegradation effectively reduced the TSS, COD, and BOD. The anaerobe reactors were more effective at removing these pollutants, with a maximum TSS reduction of 81.1%, COD removal efficiency of 90.1%, and BOD removal efficiency of 80.2%. The longer acclimatization time of the anaerobe reactor may make it more efficient after acclimatization compared to the aerobe reactor. Although the anaerobe reactor may require a longer acclimatization time, it ultimately results in a higher efficiency in terms of TSS, COD, and BOD reduction compared to the aerobe reactor.

Extrusion technology allows the preparation of analog rice, an artificial product made of carbohydrate sources other than rice, with characteristics similar to natural rice. In this study, we aimed at determining the effect of composition and temperature on the nutritional content of analog rice obtained using heat extrusion technology. The physical properties and acceptability of the resulting product were also studied. Skim milk, sago, mung bean, and corn flour as well as the binder carboxymethyl cellulose (CMC) were used. The procedure was conducted in four stages: raw-material preparation, formulation, physicochemical evaluation, and sensory property evaluation. The best analog rice formula was established as 50% sago flour, 30% corn flour, 19.2% mung bean flour, 0.4% skim milk, and 0.4% CMC. The panelists’ most preferred rice analog formula was the one with the highest sago starch and skim milk content. The extrusion temperature did not significantly affect the nutrient content. However, it had a considerable impact on the thermal profile and physical properties, such as appearance and granular morphology.

Solid sago waste is a potential source of producing renewable energy in the form of biogas. This study investigated the effects of solid sago waste particle size, biological pretreatment using a microbial consortium of lignocelluloses, pretreatment with NaOH, and the ratio between solid sago waste and cow rumen based on the biogas production rate. Several variations of these conditions were used to achieve this. The anaerobic digestion process was conducted over two months at 30.42 °C ± 0.05 °C, and the biogas production rate was measured every two days. The 1:1 ratio showed better results compared to the 2:1, because it allows the bacteria to achieve metabolic balance. The highest cumulative biogas production (27.91 mL/g TS) was generated when the sago waste underwent milling (±1 mm), pretreatment with 4% NaOH g/g TS, and treatment with microbial consortium 5% v/v at a 1:1 ratio of solid sago waste to the rumen.

Landfills in developing countries, like Indonesia are dominated by organic solid waste, with water content reaching 80%. It is impossible to manage them by incineration processes. Naturally, all organic material can decompose and produce methane gas, carbon, water, as well as leave blackish fine soil-like material, called compost. Therefore, the recovery of the landfills can be done by using landfill mining methods. However, the benefits, costs, and environmental impacts of landfill mining are highly dependent on landfills age, material characteristics, disposal systems, economic and social development of the community, and climate. The main objective of this study was to analyze the optimum age of garbage heaps to obtain the right time on the recovery of the landfills. Five excavation points were prepared at 4-5,6-7,8-9,10-11, and > 12 years. Each excavated material was dried, separated, and grouped according to each component, and then weighed, tabulated, and shown as a percentage of excavated garbage composition. The result shows that landfill mining can be carried out at a garbage heap aged 8-9 years in which compost landfill mining has obtained at 50%. Other discussions concern the existence of organic and nonorganic components as well as the usage of plastic bags and nappies indicating the lifestyle changes of the people.

The effect of pH and operation mode for COD removal of slaughterhouse wastewater with Anaerobic Batch Reactor (ABR)

Enhanced biogas production from rice straw with various pretreatment : a review