6 research outputs found

    PENGARUH PUPUK ORGANIK PADAT LIMBAH KELAPA SAWIT DAN PUPUK NITROGEN TERHADAP SIFAT KIMIA TANAH SERTA PERTUMBUHAN DAN HASIL SAWI (Brasicca juncea)

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    Penggunaan pupuk sintetik dalam jangka panjang dapat merusak tanah dan menurunkan hasil tanaman sehingga tanah tidak mampu lagi meningkatkan produktivitasnya. Hal ini menuntut kita untuk mencari teknologi alternatif yang mampu mengurangi penggunaan pupuk sintetik adalah dengan menggunakan bahan organik. Namun kebutuhan unsur hara yang di butuhkan oleh tanaman tidak semuanya dapat dipenuhi oleh pupuk organik sehingga penggunaannya perlu dikombinasikan dengan pupuk sintetik. Tujuan penelitian ini adalah untuk mendapatkan kombinasi dosis pupuk organik padat dan pupuk nitrogen terhadap sifat-sifat kimia tanah serta pertumbuhan dan hasil sawi. Penelitian ini dilaksanakan pada bulan Juni-September 2016 di rumah kaca dan Laboratorium Ilmu Tanah Universitas Bengkulu. Tanah yang digunakan adalah Ultisol yang berasal dari daerah Kandang Limun Kecamatan Muara Bangkahulu. Pada penelitian ini digunakan benih sawi (panah merah) yang ditanam pada polibag yang disusun berdasarkan Rancangan Acak Lengkap dengan tiga ulangan dan 12 perlakuan yaitu P0N0 Kontrol, P0N1 : 50 kg ha -1 , P0N2 : 100 kg ha -1 urea, P1N0 : 7.5 ton ha -1 POP, P1N1 : 7.5 ton ha -1 POP + 50 kg ha -1 urea, P1N2 : 7.5 ton ha -1 POP + 100 kg ha -1 urea, P2N0 : 15 ton ha -1 tanpa urea, setara dengan 7.5 gr polibag - 1, P2N1 : 15 ton ha -1 POP + 50 kg ha urea, P2N2 : 15 ton ha -1 POP + 100 kg ha -1 urea, P3N0 : 22.5 ton ha -1 tanpa urea, P3N1 : 22.5 ton ha -1 POP + 50 kg ha -1 urea, P3N2: 22.5 ton ha -1 POP + 100 kg ha urea. Variabel pengamatan pada penelitian ini adalah N Total, P tersedia, K-dd, Al-dd, C-Organik, pH H O, Jumlah daun, kehijauan daun, berat basah berangkasan atas, berat basah brangkasan bawah, berat kering berangkasan atas dan berat kering berangkasan bawah. Hasil penelitian menunjukkan bahwa penambahan pupuk organik pada dosis 15 ton ha 2 POP tanpa urea, dapat memperbaiki sifat kimia tanah yang diindikasikan dari peningkatan P tersedia, K dapat ditukar, pH tanah dan penuruan Al-dd pemberian 15 ton ha POP + 100 kg ha -1 urea sampai 22,5 ton ha -1 POP tanpa urea, menghasilkan jumlah daun dan bobot basah tanaman tertinggi. -1 -1 -1 -

    Measurement of Interactions between Solid Particles, Liquid Droplets, and/or Gas Bubbles in a Liquid using an Integrated Thin Film Drainage Apparatus

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    A novel device was designed to measure drainage dynamics of thin liquid films confined between a solid particle, an immiscible liquid droplet, and/or gas bubble. Equipped with a bimorph force sensor, a computer-interfaced video capture, and a data acquisition system, the newly designed integrated thin film drainage apparatus (ITFDA) allows for the direct and simultaneous measurements of force barrier, true film drainage time, and bubble/droplet deformation under a well-controlled external force, receding and advancing contact angles, capillary force, and adhesion (detachment) force between an air bubble or oil droplet and a solid, a liquid, or an air bubble in an immiscible liquid. Using the diaphragm of a high-frequency speaker as the drive mechanism for the air bubble or oil droplet attached to a capillary tube, this newly designed device is capable of measuring forces over a wide range of hydrodynamic conditions, including bubble approach and retract velocities up to 50 mm/s and displacement range up to 1 mm. The results showed that the ITFDA was capable of measuring hydrodynamic resistance, film drainage time, and other important physical parameters between air bubbles and solid particles in aqueous solutions. As an example of illustrating the versatility, the ITFDA was also applied to other important systems such as interactions between air bubble and oil droplet, two air bubbles, and two oil droplets in an aqueous solution

    Measurement of Interactions between Solid Particles, Liquid Droplets, and/or Gas Bubbles in a Liquid using an Integrated Thin Film Drainage Apparatus

    No full text
    A novel device was designed to measure drainage dynamics of thin liquid films confined between a solid particle, an immiscible liquid droplet, and/or gas bubble. Equipped with a bimorph force sensor, a computer-interfaced video capture, and a data acquisition system, the newly designed integrated thin film drainage apparatus (ITFDA) allows for the direct and simultaneous measurements of force barrier, true film drainage time, and bubble/droplet deformation under a well-controlled external force, receding and advancing contact angles, capillary force, and adhesion (detachment) force between an air bubble or oil droplet and a solid, a liquid, or an air bubble in an immiscible liquid. Using the diaphragm of a high-frequency speaker as the drive mechanism for the air bubble or oil droplet attached to a capillary tube, this newly designed device is capable of measuring forces over a wide range of hydrodynamic conditions, including bubble approach and retract velocities up to 50 mm/s and displacement range up to 1 mm. The results showed that the ITFDA was capable of measuring hydrodynamic resistance, film drainage time, and other important physical parameters between air bubbles and solid particles in aqueous solutions. As an example of illustrating the versatility, the ITFDA was also applied to other important systems such as interactions between air bubble and oil droplet, two air bubbles, and two oil droplets in an aqueous solution

    Biodiesel-Assisted Ambient Aqueous Bitumen Extraction (BA<sup>3</sup>BE) from Athabasca Oil Sands

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    The water-based extraction process has been almost exclusively used in the current industry for Athabasca oil sands extraction to produce bitumen and heavy oil. However, the current method is facing various challenges, primarily including high energy intensity, poor processability with poor-quality ores, large consumption of fresh water, and concerns on considerable volume of tailings. Although the technology of using nonaqueous solvent as extraction medium has numerous advantages, problems such as solvent loss to tailings and high capital/operating costs are difficult to address. A biodiesel-assisted ambient aqueous bitumen extraction (BA<sup>3</sup>BE) process has been herein proposed as an alternative to water-based and solvent-based extraction processes. The results showed a significant improvement in both froth quality and bitumen recovery (increased from ∼10% to ∼80% with biodiesel addition) for processing poor-quality ores at ambient temperature (25 °C), which is much lower than the temperatures used in the current industrial practice (40–55 °C). The aqueous tailings generated in the BA<sup>3</sup>BE process were found to feature faster settling and enhanced densification, which is favorable for recovering processing water and improving land reclamation. Furthermore, the innovative BA<sup>3</sup>BE extraction process requires similar facilities and procedures as the current industrial processes, which can be considered as an advantage for commercialization

    Study of Bitumen Liberation from Oil Sands Ores by Online Visualization

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    A novel visualization cell was designed to study the kinetics of bitumen liberation from oil sands. This novel visualization cell allows for direct observation of bitumen recession from sand grains in real time under various experimental conditions, thereby providing a better understanding of bitumen liberation and the critical role of process conditions in bitumen extraction from oil sands ores. Although direct recession of bitumen from sand grains is found to be the primary mechanism of bitumen liberation, the presence of entrained air in oil sands ores greatly enhances bitumen liberation via bitumen spreading over air bubbles. Imaging analysis of the recorded real-time bitumen liberation process allowed for quantitative analysis of bitumen liberation kinetics. A rapid bitumen recession and, consequently, high bitumen recovery were observed for a good processing ore, in contrast to a slower bitumen liberation and lower bitumen recovery for a high-fines ore, which was considered to be a poor processing ore. The weathering (aging) of good processing ore was found to significantly reduce bitumen liberation kinetics, leading to a lower bitumen recovery, even though the bitumen content and solids composition of the ore remained the same. These findings confirmed the critical role of bitumen liberation in bitumen extraction. Increasing the process water temperature was found to increase significantly bitumen liberation kinetics and led to a higher degree of bitumen liberation. While high pH facilitated bitumen liberation, the presence of excessive salts (16 000 ppm sodium) was found to be detrimental to bitumen liberation, in particular at high pH. The bitumen liberation study using this novel visualization cell was extremely valuable for identifying and understanding critical operating parameters that control bitumen liberation and, hence, ore processability, providing a scientific basis for designing breakthrough technology to improve processability of oil sands ores and reducing the environmental impact of oil sands development

    Asphaltene Subfractions Responsible for Stabilizing Water-in-Crude Oil Emulsions. Part 2: Molecular Representations and Molecular Dynamics Simulations

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    After successful isolation of the most interfacially active subfraction of asphaltenes (IAAs) reported in the first part of this series of publications, comprehensive chemical analyses including ES-MS, elemental analysis, Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) spectrometry were used to determine how the molecular fingerprint features of IAAs are different from those of the remaining asphaltenes (RAs). Compared with the RAs, the IAA molecules were shown to have higher molecular weight and higher contents of heteroatoms (e.g., three times higher oxygen content). The analysis on the elemental content and FTIR spectroscopy suggested that IAAs contained higher contents of high-polarity sulfoxide groups than the RAs. The results of ES-MS, NMR, FTIR, and elemental analyses were used to construct average molecular representations of IAA and RA molecules. These structures were used in molecular dynamics (MD) simulation to study interfacial and aggregation behaviors of the proposed molecules. The MD simulation study showed little affinity of representative RA molecules to the oil/water interface, while the representative IAA molecules had much higher interfacial activity, reflecting the extraction method. The aggregation of IAA molecules in the bulk oil phase and their adsorption at oil/water interface were not directly related to the ring system, but rather to the associations between or including sulfoxide groups. During the simulation, the IAA molecules were found to be self-assembled in solvent, forming supramolecular structures and a porous network at the oil/water interface, as suggested in our previous work. The results obtained in this study provide a better understanding of the role of asphaltenes in stabilizing petroleum emulsions
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