26 research outputs found
PENGARUH PENAMBAHAN NITROGEN dalam PRODUKSI BIOETANOL dari MOLASE TEBU dengan METODE SIMULTANEOUS SACCHARIFICATION and FERMENTATION (SSF) MENGGUNAKAN Saccharomyces cerevisiae
No full textMolase adalah limbah tebu yang memiliki kandungan gula tinggi dan memiliki potensi untuk dijadikan sebagai bahan bakar seperti bioetanol. Pemanfaatan molase menjadi energi merupakan salah satu bentuk mewujudkan konsep bio-energy untu mewujudkan sistem lingkungan yang berkelanjutan. Pembuatan bioetanol dilakukan melalui teknik fermentasi. Penelitian ini dilakukan dengan membandingkan pengaruh penambahan nitrogen dan tanpa nitrogen pada media selama proses fermentasi molase tebu secara Simultaneous Sacharification and Fermentation (SSF). Proses hidrolisis molase tebu dilakukan secara biologis menggunakan Aspergillus niger. Sedangkan Poses fermentasi menggunakan isolat Saccharomyces cerevisiae. Dengan menggunakan metoda gas kromatografi didapatkan kadar bioetanol tertinggi pada pelakuan penambahan nitrogen dengan nilai 6,8% v/v sedangkan untuk perlakuan tanpa nitrogen memiliki kadar etanol tertinggi sebesar 4,5% v/v pada jam ke 72. Hal ini disebabkan karena nitrogen membantu meningkatkan aktivitas enzimatik mikroorganisme dalam proses konversi gula menjadi bioetanol. </jats:p
Characterization of Post-Mining Soil and Solid Waste from Silica Sand Purification
No full textPost-mining soil and solid waste from the silica sand refining industry is widespread and the potential long-term impact of toxic metals and metalloids is a significant and under-appreciated issue. This study presents the characteristics of post-mining soil and solid waste resulting from silica sand purification to observe its physical, chemical, and biological composition. Analysis of the physical properties was carried out with reference to ASTM 112-10 and the results show that post-mining soil contains 36.95% sand, 18.80% clay, and 42.74% silt, with coefficients of permeability and porosity of 0.69×10-6 cm•s-1 and 35.84%, respectively. Meanwhile, the solid waste contains 43.35% sand, 35.96% clay, and 20.68% silt with coefficients of permeability and porosity of 1.49×10-6 cm•s-1 and 51.12%. The overall mineralogy and morphology of both samples showed that they have the same chemical composition as gehlenite (Ca2Al2SiO7), spinel (MgAl2O4), akermanite (Ca2MgSi2O7), monticellite (CaMgSiO4), aluminum oxide (Al2O3), magnetite (Fe3O4), and hematite (Fe2O3) supports this data. The chemical composition of both samples is SiO2, Al2O3, CaO, and MgO, but the post-mining soil has lower heavy metal and nutrient contents compared to solid waste. Meanwhile, solid waste has a high content of heavy metals and nutrients due to washing and bonding from the silica sand purification process. The abundance of bacteria (Colony Forming Unit) for the 10-4 and 10-5 dilutions in post-mining soil was 1.59×103and not detected, while in the solid waste, 4.10×105 and 1.64×105 were found, respectively. This study can be used as base values for modifying the two samples, which can be applied in mining land reclamation
Simulated degradation of low-density polyethylene and polypropylene due to ultraviolet radiation and water velocity in the aquatic environment
No full textLow-density polyethylene (LDPE) and polypropylene (PP) are the two main polymers with extensive applications. It might lead to plastic pollution and degradation in the aquatic environment. Former laboratory simulation studies of plastic degradation have been presented. However, most of the studies were only applied a single degradation agent without specific environmental conditions, which indicated a research gap. This research aimed to investigate LDPE and PP degradation under the influence of UV radiation and water velocity with specific environmental conditions. Five reactors of simulated aquatic environments were adjusted to desire calculated UV B dose of 158.98-438.91 W.S/cm2 and water velocity variations of the Surabaya River, one of Indonesia's urban rivers that has been polluted by microplastics. The water velocity was set in high (0.3-0.6 m/s) and low ones (0.1-0.3 m/s) to represent the fluctuated river discharge at rain and dry seasons. Total simulation time of 480 h (8 h/day for 60 days simulation) has initiated LDPE and PP degradation. LDPE experienced more weight loss (3.07) under the combined exposure of UV and high water velocity, than PP (2.37) under high water velocity. Synergetic effects of photodegradation, physical-mechanical, and hydrolysis degradation mechanisms could affect more severe crack tip formation of LDPE and PP rather than in single agent simulation. Major surface morphology deterioration of LDPE and PP, changes in transmittance intensities, carbonyl index in this study have revealed the importance of combined exposure of UV radiation and water velocity to plastic degradation in the aquatic environment
Comparing Life Cycle Assessment of Fish Preservation Method on Fishing Vessels in Indonesia
Full text link\ua9 Published under licence by IOP Publishing Ltd.The economic benefit that the fishermen can obtain primarily depends on the quality of their catches. Therefore, it is essential to ensure that the caught fish stays fresh until entering the market. The most common fish preservation on traditional fishing boats in Indonesia is block ice, which must be carried in the fish hold from the home port. In comparison, another alternative method for fish preservation is the Flake Ice machine that can produce ice on-board. The study on Life Cycle Assessment (LCA) was conducted on these two fish preservation methods to understand the environmental impact of each technique. For undertaking the assessments, LCA software known as SimaPro was employed. The system boundary for the LCA about fish preservation applied the "well to wheels"approach and covered the whole service life of the vessel for the full consecutive 20 years of operation. The functional unit for the assessment was fish preservation of 4 tonnes during a 7-day fishing trip. The input of the evaluation was the materials and energy required to produce the amount of ice or to operate a refrigeration system for each year of the vessel\u27s operation, with a total of 30 trips per year. The paper explored the environmental impact of these two fish preservation methods in terms of Ozone Layer Depletion and Global Warming
Evaluation Of Landfill Management At Gunung Kupang Landfill, Banjarbaru City
No full textBanjarbaru City is the capital city of South Kalimantan Province with waste generation in 2023 of 67,854,410 kg/year. Based on the Banjarbaru City Waste Masterplan for 2021-2025 supported by Banjarbaru City Regulation No. 5 of 2023, one strategy to reduce the amount of waste dumped in landfills is the optimization and development of waste infrastructure including landfills. Waste management at the Gunung Kupang Landfill has not been optimal when viewed from the capacity of waste management. One strategy in the policy of 'Increasing Service Coverage and Quality of Management Systems' in the Masterplan is the rehabilitation of landfills that pollute the environment. Before the landfill was decided to be rehabilitated, an evaluation was carried out using the ARRPET (Asian Regional Research Program on Environmental Technology) method. An overall evaluation of the existing conditions at the Gunung Kupang Landfill has never been carried out so it needs to be carried out using the ARRPET method. The results of the environmental evaluation of the existing conditions of the Gunung Kupang Landfill with ARRPET produced a risk index score of 529.24. This value is included in the risk index with a moderate category so that the recommended follow-up is to rehabilitate the landfill into a sustainable landfill as soon as possible. Therefore, it is planned to build a methane gas installation and landfill mining in landfill zone 2 as a rehabilitation method so that the potential for environmental pollution can be minimized and the life of the landfill can be extended. Based on the evaluation results, the rehabilitation method is feasible to be carried out where the NPV of both rehabilitation methods is positive and the BCR is more than 1
EFFECT OF pH ON LIQUID-PHASE MASS TRANSFER AND DIFFUSIVITY COEFFICIENT AT LEACHATE TREATMENT OF MUNICIPAL WASTE LANDFILL IN ANAEROBIC BIOREACTOR
Full text linkLeachate is a liquid waste resulted from physical, biological and chemical decomposition of landfill waste. Leachate contains complex dissolved organic and anorganic substrate which are biodegradable and non-biodegradable. Anaerobic treatment principally utilizes anaerobic bacteria in order to degrade the dissolved organic substance into biogas. Anaerobic treatment is very sensitive towards the substrate cocentration, temperature, and pH. This research used anaerobic bioreactor with the volume of 160 L, the ratio of the leachate: biogas is 70:30. Seeding and acclimatization steps were done, respectively for 10 days, leachate treatment was done in 21 days. Seeding, acclimatization, and leachate treatment were done on the pH ambience of 7.2 and 8.0 and ambient temperature. COD and VFA analysis were done every two days. The objective of this research is to decide the pH effect on the coefficient of liquid-phase mass transfer: kL, and the diffusivity of the dissolved substace, DL. pH affects the degradation of the concentratio of dissolved organic substrate in the leachate. The higher the pH is, the higher the obtained VFA concentration is. VFA concentration is affected by pH; however, it still considers the optimal pH condition of the substrate biodegradation. pH affects the average rate of mass transfer, rkL and diffusivity of the dissolved substance, DL in the anaerobic treatment of leachate. pH affect the concentration of dissolved organic substrate which subsequently influenes the coefficient of liquid-phase mass transfer of the leachate, kL and the diffusivity of the dissolved substance, DL. The higher the pH is, the more increasing the kL is and the more decreasing the DL is
Optimasi Pengangkutan Sampah di Kecamatan Kebumen Kabupaten Kebumen
No full textKecamatan Kebumen merupakan pusat kota Kabupaten Kebumen sehingga kegiatan pengangkutan sampah difokuskan di wilayah ini. Penelitian ini bertujuan untuk mengoptimasi sistem pengangkutan sampah sehingga penggunaan sarana yang ada dapat dimaksimalkan dan anggaran yang dikeluarkan dapat diturunkan. Analisis timbulan dan densitas sampah dilakukan menggunakan metode Load-count analysis dan Weight-volume analysis. Analisis waktu, jarak, dan kecepatan kendaraan dilakukan dengan melakukan pengamatan langsung terhadap kendaraan pengangkut sampah. Pengumpulan data finansial dilakukan dengan wawancara kepada sopir dan tenaga muat truk serta pengambilan data bulanan kepada Dinas Perumahan dan Kawasan Permukiman dan Lingkungan Hidup Kabupaten Kebumen. Optimasi biaya operasional dilakukan dengan membandingkan biaya pengangkutan antara kondisi eksisting dengan hasil optimasi. Hasil penelitian menunjukkan bahwa kendaraan arm roll truck dan dump truck melakukan pengangkutan sampah sebanyak 1-2 rit/hari. Persentase pelayanan pengangkutan sampah di Kecamatan Kebumen sebesar 59,42%. Optimasi pengangkutan sampah dilakukan dengan memanfaatkan sisa waktu kerja kendaraan arm roll truck. Penambahan ritasi sebanyak 1 rit/hari menyebabkan penggunaan arm roll truck dapat direduksi dari 10 unit menjadi 7 unit. Penambahan ritasi juga mengakibatkan biaya operasional dan pemeliharaan kendaraan naik sebesar 12,70%. Pengurangan jumlah kendaraan yang digunakan membuat anggaran pengangkutan sampah yang harus dikeluarkan setiap harinya mengalami penurunan sebesar 5,06%
Characterization of Spent Bleaching Earth as an Adsorbent Material for Dye Removal
No full textInitial research has been carried out to determine the potential of SBE as an adsorbent material through chemical and surface area characterization. Several analyses were performed, including oil content, BET, SEM-EDS, XRD, FTIR, and adsorption capacity. The oil content of the SBE samples were 0.05–0.09%, well below the standard (3%) of hazardous material classification according to the Indonesian government regulation. The chemical composition of SBE, measured by EDS, was dominated by Si and Al elements. XRD analysis revealed two 2-theta diffraction peaks indicated the presence of crystalline SiO2 and Al2O3 phases. Additionally, the results of the FTIR test also showed the dominance of Si-O and Al-O-H functional groups. The SBE morphology, as observed in SEM image, exhibited irregular shape and porous surface covered by impurities. These results supported by the BET data which showed SBE surface area of 10.86 m2g-1 and a mesopore volume of 2.49 cm3 (STP)g-1. Batch adsorption study conducted using low and high range concentration of methylene blue produced a maximum adsorption capacity of 7.993 mg/g and 40.485 mg/g, respectively. The adsorption isotherm analysis showed that the adsorption mechanism was in accordance with the Langmuir isotherm model. Considering its chemical characteristic, SBE has met the criteria for adsorbent material. Nevertheless, the small surface area requires SBE to be activated prior to use
Biogas production from modification of food waste anaerobic digestion process
Full text linkFood waste is Indonesia’s largest solid waste composition, and most of it is disposed of directly into landfills. Food waste is a suitable substrate for anaerobic digestion. This study was conducted to examine the effect of adding mixed cultures of methanogen bacteria (MCB) on food waste anaerobic digestion. Variables used in this study were the percentage of MCB added and its addition frequency. The quantity of MCB added is calculated based on the percentage of MCB to the solid waste weight, which is 10%, 30%, and 50%. The frequency of MCB added is every 10 and 15 days. The addition was carried out starting on day 0. Results of this study showed that the variation of 50% MCB added every 15 days had the highest biogas cumulative production, up to 201.5 liters. The result showed that the anaerobic process was under mesophilic conditions, varying from 28-30°C. Moisture content was increased with the addition of MCB. Temperature, pH, moisture content, and C/N ratio testing were also examined at the end of the study to determine the result product quality. It was shown that moisture content and C/N value were still high, which explains that the anaerobic degradation has not been done yet
