Advanced Materials Research Vol. 1162

Abstract: Heavy metal such as Cu, Fe, and Zn are the most serious contributers to environmental problems. The removal of heavy metal from the environment is the research interest nowdays. The adsorption of Cu, Fe and Zn from wastewater was investigated with various activated carbons as adsorbents. The activated carbons were produced from oil palm leaves by using multi-activation methods. The H₃PO₄, NaOH, ZnCl₂ and KOH were chosen as chemical activating agents. Batch adsorption experiment was used to test the ability of activated carbon to remove Cu, Fe, and Zn from wastewater. The surface characteristics of activated carbon were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption-desorption isotherms. The Activated carbons were able to purify wastewater with a maximum turbidity level of 2.83 NTU. The AC-H₃PO₄ activated carbon showed the highest absorbability of Cu metal as 91.540%, while the highest absorbabilities of Zn and Fe metals were indicated by AC-KOH activated carbon of 22.853% and 82.244% absorption respectively. Therefore, these results enable the oil palm leaves to become a high potential for activated carbon as removal the heavy metals.

Abstract: This study was aimed at investigating the effect of electro-assisted and double aeration (EAPR-DA) system to enhance the lead removal in water and uptake by Pakcoy (Brassica rapa subsp. Chinensis). Variable regimes were created by 2 V of constant DC voltage using 2D stainless steel cathode-pot and Ti anode electrode, and aeration level of 10 L/min. The effectiveness of EAPR-DA, EAPR, phyto-aeration, and phytoremediation on the treatment was compared and evaluated by measuring the decrease of lead concentration in the water and accumulated in the plant using flame Atomic Absorption Spectroscopy. Plant stress was evaluated by phytomorphology changed and measurement chlorophyll content using UV-Vis Spectroscopy after the acetone extraction. The results showed that the EAPR-DA system using Pakcoy has a great ability to decrease the lead concentration in water compared with the EAPR, phyto-aeration, and phytoremediation. The removal ability in each reactor was 82.5%, 78.75%, 72.5%, and 61.875% respectively for EAPR-DA, EAPR, phytoremediation. and phyto-aeration. Excessive aeration in the root zone might inhibit lead adsorption by a plant in the phyto-aeration system. In general, the accumulation of lead in plant growth hydroponically has a large concentration in the roots compared to the shoot except for the EAPR-DA system which high adsorption of lead concentration in the shoot part. The BC (1.13) and TF (1.97) value of the EAPR-DA system was higher than the other systems, showing aeration can enhance high adsorption of lead in the root and then transported it into the shoots part. High chlorophyll total (54.89±14.31 mg/mL) and low chlorophyll a/b ratio (1.21±0.38) in the plant under the EAPR-DA system showed that the double aeration in the electro-assisted system encourages the high tolerance of the plant to the lead concentration.

Abstract: Peat waters were abundant in the West Tanjung Jabung Regency of Jambi Province. Peat water contains manganese metal ion concentration that exceeds the clean water quality standard. Previous studies have been conducted to reduce levels of manganese in peat water, but the results have not been significant. This study aims to reduce levels of Manganese metal in peat water using the composition of Bentonite and Biochar. The adsorption process was carried out at room temperature (29 °C) with a stirring of 200 rpm. Some parameters measured were optimum pH of adsorption, optimum contact time and the best combination between Bentonite and Biochar. Manganese ion concentration in solution was measured using atomic absorption spectroscopy (AAS). The results of this study indicate that the optimum conditions for removing manganese ion at pH 5 and contact time 40 minutes. Tests on artificial solutions using 0.2 grams of biochar showed Mn ion removal of 42.91% (C₀ = 100 mg/L, Ce = 57.09 mg/L, V = 100 mL). The best combination obtained in Bentonite: Biochar (1:2) with a mass of 0.080 gr and 0.170 gr, respectively, which able to remove 91.29% manganese ions in peat water.

Abstract: One of the basic needs for human is clean water. Many lowlands and marshy areas in larger islands in Indonesia such as Sumatra and Kalimantan are the source of peat water. This type of water is harmful for people living in such areas and it cannot be used directly for drinking and living. According to the standard quality of good water, peat water does not meet the requirements as a source of water for daily life. Peat water is acidic, red-brownish coloured, and it contains higher organic matters especially humic acid and its derivatives. Photocatalysis process is one of the promising way to treat solution that contains humic acid. This research aims to pre-eliminary study activity of PVDF-TiO₂/ZnO nanofiber for degradation of humic acid solution. Photocatalytic activities were studied inside photoreactor system with artificial UV radiation with 254 nm wavelength. The percentage of degradation after contacting humic acid solution to photocatalyst was determined by measuring humic acid solution before and after degradation by using UV-Vis spectrophotometer with maximum lambda in 219 nm. The rate constants were calculated and the results were 0,03909 min^-1 and 0.02832 min^-1 respectively for PVDF-4%TiO₂/ZnO and PVDF-8%TiO₂/ZnOnanofibers and it is in pseudo first order kinetic model.

Abstract: This study discusses the development of Indonesian natural zeolite and agricultural waste i.e bagasse ash and rice husk ash as natural adsorbents. These materials were used as an adsorbent for methyl orange and methylene blue adsorption for isotherm and kinetic study. Adsorption kinetic models for methyl orange and methylene blue with all adsorbents were a pseudo-second-order except methyl orange adsorption with bagasse ash adsorbent (MA) that followed pseudo-first-order. Isotherm models for all adsorption experiments were Langmuir type except methyl orange adsorption using rice husk adsorbent (MS) that followed Freundlich type.

Abstract: The validation method for determination of chemical oxygen demand (COD) with indirect UV-Vis spectrometry have been done. This method enable to easily perform highly sensitive, considerably faster and easier, and minimize the use of digestion solution. This method is the development of standard method of COD determination by closed reflux using UV-Vis spectrometry so it requires the method validation stage. The validation is used to ensure linearity, limit of detection, limit of quantification, precision, and accuracy values in accordance with quality control. This study was also carried out to formulate the uncertainty calculation modeling of COD on water analysis. The result of validation method show that the calibration curve linearity is 0.9994 with the linear regression equation Y = 0.0003X + 0.0005. The method is able to have high sensitivity in measuring COD value with low concentrations with limit of detection and limit of quantitation of 9.78 and 32.59 mg O₂/L. Indirect UV-Vis spectrometry has high precision with relative standard deviation of 0.66% and high accuracy with the percentage of recovery of 91.35%. The uncertainty formulation model on determination of COD from the source of standard uncertainty of sample volume, calibration curves, and repeatability.

Abstract: The Study on synthesis of chitosan prepared by gamma irradiation and multi-stage deacetylation as chitosan-silica membrane has been carried out. Synthesis of chitosan is carried out by deproteination with papain, demineralization, and deacetylation. Deacetylation of chitosan using gamma irradiation with 0, 5, 10, 15, 20, and 25 kGy and two and multi-stage deacetyllation. The synthesis of chitosan silica composite using sol gel method with the ratio of 1:1; 1:2; and 1:3. Based on the study, gamma irradiation increase deacetylation degree of chitosan and minimize the sodium hydroxide needed for deacetylation chitosan. The multi stage deacetylation increase the efficiency procedure for increase deacetylation degree of chitosan. Chitosan-silica composite has been synthesized by sol gel method. The gamma radiation doses have significantly influence on the deacetylation degree of chitosan. Gamma irradiation and multi stage deacetylation increase the efficiency procedure for preparation chitosan and chitosan-silica composite.

Abstract: Propolis is a poorly water-soluble substance contain natural resinous produced by honey bees. Self-nanoemulsifying (SNE) play a role not only to increase the solubility of propolis but also to improve the pharmacological activity. The aim of the present study is to fabrication and characterization self-nanoemulsifying of propolis extract (SNEPE) using virgin coconut oil (VCO) as the lipid-based vehicle. VCO (lipid-based), cremophor RH 40 (surfactant) and polyethylene glycol (PEG) 400 with concentration 10-50; 10-80; 10-40% respectively was used to construction pseudo ternary phase diagram. The formulations that selected in the pseudo ternary phase diagram is continued for the fabrication of SNEPE. The formation of SNEPE was characterized include transmittance, particle size, zeta potential, thermodynamic stability test, robustness to dilution test, and accelerated stability test. The result showed that eight formulas using 10-20% of VCO, 40-80% of cremophor RH40, and 10-40% of PEG 400 were selected for the fabrication of SNEPE. SNEPE demonstrated the transmittance more than 90%, particle size with range 9,00±0,00 to 34,10±0,30 nm, and less than-30 mV of zeta potential. The formulation passed the thermodynamic stability test. The robustness to dilution test showed that three formulas with a ratio of 20: 70: 10, 20: 60: 20, and 20: 50: 30 are the most stable formulations in various dilution. The formulas are also stable during accelerated stability study. The results can be concluded that VCO, cremophor RH40, and PEG 400 as a vehicle to produce stable SNEPE.

Abstract: Celery (Apium graveolens L.) and Bay (Syzygium polyanthum Wight) contain active compound of flavonoid which can obstruct reabsorbsion of Na and water until increase diuretic effect. This research aims to know diuretic effect combinations from celery herb and bay leaf ethanol extract 70% toward Wistar Male Mice using Lipschitz test. The research design is experimental with posttest only control group design by deviding the mice into normal group, hydrochlorothiazide group 25 mg/kg, control CMC-Na 0.5%, and combinations of celery herb (CHEE) and bay leaf ethanol extract(BLEE) treatment group. Those were made in 3 variances combinations doses which are; 1.125 mg/kg:6.25 mg/kg (combination-1), 2.25 mg/kg:12.5 mg/kg (combination-2), and 4.5 mg/kg:25 mg/kg (combination-3) and also 2 single doses of CHEE 4.5 mg/kg and BLEE 25 mg/kg. Diuretic effect is determined by a diuretic index and Lipschitz value. Urine volume is analyzed with ANOVA and continued analyzing with non parametric Kruskal-Wallis and Mann Whitney. The results of diuretic effect combinations from CHEE and BLEE showed that the three combinations have diuretic effect with value index in series from the smallest dose combinations are; 1.83, 1.86, 2.09 at 5 hours and 1.73, 1.75, 2.02 at 24 hours. Lipschitz values are 0.78, 0.79, 0.89 at 5 hours observation and 0.79, 0.79, 0.913 at 24 hours. Diuretic energy are ; 69.84%, 72.48%, 94.12% at 5 hours and 65.79%, 67.79%, 93.15% at 24 hours. Based on the test results of diuretic effects, combinations of CHEE and BLEE have diuretic effect and combination-3 which is the closest to hydrochlorothiazide.

Abstract: Diabetes mellitus prevalence has rapidly increased globally. Food contains high resistant starch (RS) may be used as a functional food to prevent and control diabetes mellitus. Resistant starch is high in raw bananas and its products such as flour. The study aimed to evaluate effects of Kepok banana flour on blood glucose and physical performance, especially body weight and feed intake in type 2 diabetic rats induced by nicotinamide (NA) and streptozotocin (STZ). Eight-week-old male Wistar rats weighed 150-200 g were randomly divided into nondiabetic and diabetic groups. Nondiabetic group (n=7 rats) was normal control (NC) and fed with standard diet AIN-93M (American Institute of Nutrition Rodent Diets 1993 for adult maintenance), while diabetic groups (n=7 rats each group) consisted of diabetic control (DC) which fed with standard diet and 3 diabetic treatment groups (T1-T3) which fed with AIN-93M containing kepok banana flour with 4%, 8% and 12% of RS respectively for 14 days. After 14 days, mean fasting blood glucose in group T1, T2 and T3 have lower blood glucose than DC significantly (p<0.05) with the highest decrease of blood glucose was on group T3. Mean of body weight in group T1, T2, T3, and NC gained significantly compared to DC group (p<0.05). Feed intake in group T1, T2, T3, and NC were less than DC significantly (p<0.05). Administration of kepok banana flour with 4%, 8% and 12% of RS is able to decrease glucose level, to restore body weight loss and to reduce feed intake in STZ-NA induced type 2 diabetic rats. Kepok banana flour can be proposed as an alternative diet in the management of type 2 diabetes.