Makara Journal of Science
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Simultaneous Combination of Electrocoagulation and Chemical Coagulation Methods for Medical Wastewater Treatment
No full textChemical coagulation, electrocoagulation, and combined electrocoagulation-chemical coagulation methods were used to reduce organic compound concentrations in medical wastewater. Some parameters in the methods were adjusted to optimize the process, including the applied current, distance between electrodes, number of electrodes, acid levels, coagulant type, and contact time. Chemical Oxygen Demand (COD) was used to indicate the total amount of organic compounds in the system. The results showed that the following conditions can be applied to achieve optimum results: 3 A of applied current, 4 pairs of electrodes, with 1 cm of distance between each electrode pair, a pH of 8, 1 g of polyaluminum chloride as the coagulant, and 3 hours of contact time. The optimum removal efficiency levels of total organic compound achieved via chemical coagulation, electrocoagulation, and the simultaneous combination of electrocoagulation-chemical coagulation methods were 41%, 62.51%, and 92.21%, respectively
Bioconcentration Factor (BCF) and Translocation Factor (TF) of Heavy Metals in Mangrove Trees of Blanakan Fish Farm
No full textIn the mangroves of Blanakan, Indonesia, silvofishery practices may play a role in maintaining the environmental quality of ponds. Mangroves are known as pollutant traps since their root systems absorb and accumulate materials. Heavy metals are pollutants that often contaminate aquatic environment like ponds. The bioconcentration factor can be used to evaluate the content of heavy metals in organisms, while the translocation factor can be used to measure the amount of heavy metals transferred form one organ to another. The aim of this study was to determine the bioconcentration factor and the translocation factor of heavy metals (Pb, Cu, and Zn) in mangrove trees (Avicennia and Rhizopora) at the Blanakan ponds. Samples of mangrove trees from 3 stations, were cut using a knife, and samples of sediments were collected using Ekman Bottom Grab sampler. Samples were then prepared for heavy metal content analysis using the Shimadzu 6300 atomic absorption spectrophotometer. The bioconcentration and translocation factors were calculated using formulas; the bioconcentration factor was calculated as the content of heavy metals in trees divided by the content of heavy metals in sediments. Results showed that the bioconcentration factor of Cu was higher than 1 in the roots, stems and leaves of Avicennia trees and of Zn was higher than 1 in the roots of Rhizopora trees at station 1. Translocation factors higher than 1 were mostly found in Avicennia (Cu) and Rhizopora (Pb) trees. Mangrove trees with translocation values of greater than 1 for one or more heavy metals can be considered as strong accumulators of the corresponding metals
Deposition and Characterisation of Pd-xSb2S3 Thin Films for Sustainable Solar Energy Applications
No full textThis study reports on the effects of different concentrations of palladium impurities on the optical and compositional properties of palladium-doped antimony sulfide (Pd-xSb2S3) thin films grown by the chemical bath deposition method. The films were grown at room temperature (25 °C) with other condition, such as pH at 3.2 and the complexing agent (polyvinyl alcohol), was kept constant. The concentration of the dopants was varied between 0.3 and 0.5 M. The films were annealed at an annealing temperature of 100 °C with the annealing time of 90 min. The films were characterized using the Rutherford backscattering spectrometry (RBS) techniques and optical spectroscopy (transmittance versus wavelength and absorbance versus wavelength) to investigate the composition and optical constants (optical absorption coefficient, energy bandgap, and extinction coefficient), respectively. The results show that the transmittances of the doped layers were higher than that of the as-deposited layers. The energy bandgap of the layers was direct and typically ≤ 2.80 eV
Fe(III) Oxide-modified Indonesian Bentonite for Catalytic Photodegradation of Phenol in Water
No full textPhenol, which is a major organic pollutant, is usually detected in industrial wastewater, and thus the wastewater should be processed further before discharged into water bodies. Application of heterogeneous catalysis using natural-based materials is known to be effective and environmentally friendly in removing hazardous substances in water. In this study, local natural bentonite from the Tapanuli region in Indonesia was modified to eliminate dissolved phenol. Elimination by photodegradation reaction was conducted in a photo-Fenton system utilizing Fe(III) oxide-modified bentonite (Fe-B) as catalyst. Fe-B was prepared by a cation exchanging process using mixture solutions of NaOH and FeCl3 with OH/Fe molar ratio of 2:1 and calcined at 300 °C. Material characterization was performed by X-ray diffraction (XRD), low-angle XRD, Fourier transform infrared spectroscopy and atomic absorption spectroscopy. The reaction components consisted of ultraviolet C light, H2O2, and Fe-B, and they were processed in a batch reactor. The role of each component was analyzed by a series of reaction conditions (i.e., adsorption, photolysis, H2O2 effect, Fenton, and homogeneous photo-Fenton). The heterogeneous photo-Fenton system was found to be essential for phenol degradation, as none of the reaction conditions caused total phenol removal in the 180 min reaction time. To conclude, heterogeneous photo-Fenton gave the highest photodegradation activity, and the best experimental condition for 1.10 mM phenol removal was 5 g L-1 catalyst, 78.35 mM H2O2, and 90 min reaction time. 
Morphological, Chemical, and Thermal Characteristics of Nanofibrillated Cellulose Isolated Using Chemo-mechanical Methods
No full textThe objective of this research was to analyze the morphology, crystallinity, elemental components, and functional group changes, as well as thermal stability of nanofibrillated cellulose (NFC). Nanofibrillated cellulose has an irregular and aggregated shape with a diameter of about 100 nm. NFC self-aggregations were observed due to hydrogen bonding and Van-der Waals forces. The cellulose crystallinity index, atomic size, and polymorph of the NFC sample were found to be 63.57%, 2.2 nm, and cellulose I, respectively. The NFC sample was composed of various elemental components, such as C, O, N, Na, Al, Si, and K. IR analysis showed only small amounts of hemicellulose and lignin deposits, whereas cellulose functional groups appeared in several wavenumbers. Aromatic and oxygenated compounds, such as carboxylic acids, phenols, ketones, and aldehydes, were deposited as extractive on NFC; these compounds were associated with cellulose, hemicellulose, and lignin. The NFC thermal degradation process consisted of four steps: water evaporation (50-90 ºC); hemicellulose degradation and glycosidic linkage cleavage (250-325 ºC); amorphous cellulose and lignin degradation (325-429.29 ºC); and cellulose crystalline degradation (above 429.29 ºC)
The Abundance of Nitrogen Fixing, Nitrifying, Denitrifying and Ammonifying Bacteria in the Soil of Tropical Rainforests and Oil Palm Plantations in Jambi
No full textAlterations in the use of land for oil palm plantations can change the domination and activity of soil bacteria. More specifically, alteration in soil microbial communities can directly affect soil ecosystem functioning, particularly with respect to carbon and nitrogen cycles. Nitrogen can be a limiting nutrient, and the availability of nitrogen in the soil environment becomes a major factor in controlling the production of biomass. This research project aimed at studying the abundance of nitrogen-fixing, nitrogen-oxidizing, nitrogen-reducing, and ammonifying bacteria based on their functional genes in the tropical rain forests of Taman Nasional Bukit Duabelas (TNBD) and the oil palm plantations in Sarolangun Jambi. Samples were collected in November 2015. Soil sampling was performed randomly at three points representing each area of the tropical rainforests of TNBD and the seven- to eight-year-old oil palm plantations. Soil samples were collected using a soil sample core from 0–15 cm below the surface with depth strata of 0–5 cm, 5–10 cm, and 10–15 cm. Composite assessment was conducted on samples from each point corresponding to each respective depth strata. Soil samples were stored at -20ºC prior to testing. Microbial abundance was measured using the most probable number (MPN) method. The abundance of microbes that play a role in nitrogen metabolism between strata of 5–10 cm and 10–15 cm does not appear to be different. The highest abundance of microbes in oil palm plantation land in Jambi was found in samples with nitrifying bacteria, later followed by denitrifying, nitrogen-fixing, and ammonifying bacteria. Ultimately, it was found that microbial abundance in oil palm plantations was higher than the corresponding rates in samples from tropical rainforests
Morphological Evaluation of Tomato (Solanum lycopersicum Linn.) Cultivars
No full textTomato (Solanum lycopersicum Linn.) is widely cultivated and is economically beneficial. Tomato cultivars were obtained from traditional agriculture systems, and their morphological characters were evaluated. The cultivars included Pepper tomato [ED/CH/01], Edo local [ED/CH/02], Golden tomato [ED/CH/03] and Derica tomato [ED/CH/04]. Results of the principal component analyses of 27 morphological characters indicated that two characters accounted for 94.65 % of the observed variations. Scatter plots suggested good tendency of grouping for the four accessions. In the dendrogram, two clusters were formed with ED/CH/01, ED/CH/02 and ED/CH/03 grouped together whereas ED/CH/04 clustered separately. The clustering pattern implicated a common origin and/or gene pool for the cultivars. Cultivars ED/CH/01, ED/CH/03 and ED/CH/04 showed determinate growth type, while ED/CH/02 showed a semi-determinate growth pattern. Further, in terms of plant size, ED/CH/01 and ED/CH/02 were intermediate, while ED/CH/03 and ED/CH/04 were large. The characteristics of the flower and fruits exhibited diversity in terms of the corolla color, style, shape, fruit size at maturity, exterior color of the mature fruit, fruit shoulder, fruit cross-sectional shape, and fruit blossom end shape. These cultivars collectively possess characteristics that can be used by plant breeders. We recommend that further characterization using molecular techniques as well as conservation attention for these local germplasms should be conducte
Kaon Photoproduction: From an Experimental Point of View
No full textToday, laboratory experiments conducted worldwide continue to search for undiscovered excited states of the nucleon. The database has been continually updated over the past years to allow for nearly model-independent partial wave analyses (PWA) to be carried out in the search for such undiscovered states. The photoproduction of mesons, such as kaons, has been studied extensively in the past. However, there is still much information that can be gathered and learned from the photoproduction of the kaon. Recent coupled-channel analyses have found strong sensitivity of the K+L channel to several higher mass nucleon resonances. Various experiments have provided new and interesting results that are discussed in this short review
Activity of Cytotoxic Flavanoids against a P-388 Murine Leukemia Cell Line from the Stem Bark of Aglaia elliptica (Meliaceae)
No full textTwo mixtures of flavanoid compounds (1 and 2), a mixture of catechin (1a) and epicatechin (1b), and a mixture of gallocatechin (2a) and epigallocatechin (2b), were isolated from the active fraction of the stem bark of Aglaia elliptica methanol extract. The chemical structure of the compounds was identified with spectroscopic data, including UV, IR, NMR (1H, 13C, DEPT 135°, HMQC, HMBC, 1H-1H COSY), and MS, and additionally compared with previously reported spectral data. All compounds were evaluated for their cytotoxic effects against P-388 murine leukemia cells. Compound 2 showed cytotoxicity against the P-388 murine leukemia cell, with an IC50 value of 7.79 µg/mL, but compound 1 was found not to be active (more than 100 µg/mL)
Identification of Massoia Lactone and its Hydroxy-derivative from Kabatiella caulivora, an Endophyte of the Terrestrial Plant Alyxia reinwardtii
No full textMassoia lactone (1) and its derivative, 3,5-dihydroxydecanoic acid-d-lactone (2), were identified from an ethyl acetate extract of the endophytic fungus Kabatiella caulivora, isolated from its host Alyxia reinwardtii. The compounds were identified by GC-MS. To the best of our knowledge, this is the first report of the identification of massoia lactone and its derivative from the endophytic K. caulivora fungus.