Borneo Science | The Journal of Science and Technology

USED LUBRICATING OIL TREATMENT USING ACID ACTIVATION CLAY AS ADSORBENT FOR OIL RECOVERY

S M Anisuzzaman — 2024-09-18

The aim of this study was to assess the effectiveness of activated clay as an adsorbent in the recycling of used lubricating oil (ULO). To accomplish this, the research primarily concentrated on identifying the optimal parameters for the application of organic acids—specifically acetic acid and citric acid—in the acid activation of clay during the adsorption process. Montmorillonite K-10 clay served as the adsorbent and was activated to facilitate ULO recovery. According to the experimental findings, citric acid at a concentration of 1.0 mol/L for a reaction time of 45 minutes proved to be the most effective for ULO recovery. The optimal activated clay exhibited a viscosity of 95.10 cP and a density of 0.663 g/mL, achieving a water removal rate of 0.036% and sludge removal of up to 9.20%. Moreover, clay treated with citric acid produced a current of 1.3293 A, in comparison to 1.5721 A for acetic acid under identical conditions, as measured by Ultraviolet-visible (UV-Vis) spectrophotometry. The conditions involving citric acid at 1.0 mol/L for 45 minutes were further investigated using a scanning electron microscope (SEM) to analyze the clay before and after activation. Results indicated that the surface of the unmodified clay was smoother with fewer visible pores, whereas the activated clay displayed a more porous structure, with noticeable pores and cracks. The activated clay's average pore diameter was found to be larger, reflecting a 32.19% increase in pore size compared to the unmodified clay. Additionally, a considerable enhancement in pore area was observed, with the average pore size increasing from 1.614 μm to 2.077 μm, suggesting improved adsorption performance following
activation. Fourier transform infrared spectroscopy (FTIR) was utilized to characterize and compare the recovered oil, revealing that activated clay treated with citric acid at 1.0 mol/L for 45 minutes was superior in eliminating most remaining contaminants, such as soot, water, fuel residues, carbonyl groups, discoloration, and other impurities compared to its pre-activated state.

FOREST FOR DOMESTIC WATER CATCHMENT OF GUNUNG TEBU FOREST RESERVES, TERENGGANU

Norliyana Adnan — 2024-09-27

Forests play an important role as water catchments for all downstream demands, suchas domestic, industrial, and agricultural use. They provide not only quantity of water but also good-quality clean water. Forests help prevent impurities from entering streams, lakes, and groundwater in several ways. This process is called water purification but occurs naturally. The objective of this paper is to evaluate the importance of forest reserves, specifically the Gunung Tebu Forest Reserve (FR) in Besut, Terengganu, as a water catchment, especially for domestic use. Data on Bukit Bunga Water Treatment Plants (WTP) intakes, cost information, and forest land uses from the National Forest Inventory V (NFI V) are the main inputs for the analysis. Results show that the overall average marginal value for Gunung Tebu FR is RM297.24/ha/year. This value can be used to consider the operational cost implications of WTPs for the water purification services provided by the FR. A comparative analysis of the water catchment for Bukit Bunga WTP covers an area of 6,456.4 ha, of which approximately 88.6% is the Gunung Tebu FR. Therefore, the conservation of forest reserves as water catchment areas is important to ensure the availability of clean water, especially for domestic use.

SOIL LOSS PREDICTION USING REVISED UNIVERSAL SOIL LOSS EQUATION (RUSLE) MODEL IN KUNDASANG, SABAH

Aiman Nabila Abdul Malik — 2024-09-18

Soil erosion poses a significant environmental issue in Kundasang, Sabah, which is situated in the highlands and is recognized for its soil erosion challenges. The natural forces of water gradually wear away the topsoil of fields, leading to soil erosion. This phenomenon is often exacerbated by various triggering factors such as agricultural practices, deforestation, and unsustainable development. The region is particularly noted for its temperate vegetable cultivation. This study aimed to spatially estimate potential soil loss or erosion using the Revised Universal Soil Loss Equation (RUSLE) model. The RUSLE model incorporates six parameters, all expressed quantitatively in an equation to calculate soil erosion for a specific area. These parameters include rainfall erosivity (R), soil erodibility factor (K), slope length and steepness factor (LS), cultivation and management factor (C), and conservation support practice factor (P). The analysis leverages databases of soil types, topography, land use, and precipitation. The results indicate that only 3.11% (271.92 ha) and 0.72% (62.51 ha) of the study area is categorized as having high and very high erosion potential, respectively.

ON THE DIOPHANTINE EQUATION P x + Q y = Z 2

Izzati Izyani Japar — 2024-09-27

A Diophantine equation is a polynomial equation involving two or more variables for which integral solutions are sought. An exponential Diophantine equation includes additional variables that appear as exponents. This paper focuses on determining integral solutions to the Diophantine equation px + qy = z2, given that x + y = 5, where p and q are twin primes, cousin primes, sexy primes, or any positive integers. By analyzing the solution patterns for each scenario, we aim to develop theorems and lemmas. The findings in this paper demonstrate that, for all cases where x + y = 5, the Diophantine equation does not have any non-trivial solutions when p and q are twin primes, cousin primes, or sexy primes, but it does have infinitely many solutions for any positive integers.

NOTES ON BATS’ DIVERSITY IN PARCEL 5 OF SEKAR IMEJ CONSERVATION AREA FROM KIBUNDU, GEROWONG AND MONJUK TRAILS

Nurul ‘Ain Elias — 2024-09-18

The study on bat diversity in Sekar Imej Conservation Area (SICA) was conducted during the Sekar Imej Conservation Area Scientific Expedition from 19 September 2022 to 24 September 2022. Harp traps and mist nets were used to capture bats with placements along forest trails in Kibundu, Gerowong, and Monjuk for six consecutive nights. Species identification was performed on-site through morphological examinations of the forearm, ear, hindfoot, and tail (when available), with measurements recorded in millimeters (mm). Additionally, the bats were weighed in grams and their reproductive stages were noted. The study recorded nine bat species, belonging to four families: Pteropodidae, Rhinolophidae, Hipposideridae, and Vespertilionidae. From the Kibundu trail, Rhinolophus trifoliatus, Kerivoula intermedia and Kerivoula pellucida were collected, while Hipposideros cervinus, Kerivoula papillosa and Balionycteris maculata were recorded at Gerowong trail. At Monjuk trail, five species were recorded: Cynopterus brachyotis, Balionycteris maculata, Rhinolophus borneensis, Hipposideros cervinus and Kerivoula whiteheadi. These results will support the Sekar Imej Estate management in improving and expanding their conservation efforts and management strategies for bats and other wildlife in the landscape.