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)
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
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
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
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
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
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