The influence of pyrolysis and matrix modifiers on determination of Cr and Pb in sediment samples by GFAAS

Abstract: The Influence of pyrolysis and matrix modifiers on determination of Cr and Pb in sediment samples using graphite furnace atomic absorption spectrometry has been investigated. The sediment samples including three certified reference materials (CRMs) are reported. Analyses were performed using microwave assisted dissolution. The matrix modifiers Mg(NO3)2, Pd+Mg(NO3)2 and NH4H2PO4were shown to be optimazed. The recovery for Cr and Pb in CRMs in the case of sample dissolution was found to be between 81 to 91% for Cr and 94 to 98% for Pb of the certified values, respectively.Keywords: Sediment, Pyrolysis, Matrix modifiers, Cr, PbAbstrak (Indonesia): Pengaruh pirolisis dan matriks pengubah pada penentuan Cr dan Pb dalam sampel sedimen menggunakan tungku grafit spektroskopi serapan atom telah diteliti. Sampel sedimen termasuk tiga bahan referensi bersertifikat (CRMs) dilaporkan dianalisis dengan menggunakan bantuan microwave ekstraktor. Matriks pengubah Mg(NO3)2, Pd+Mg(NO3)2 dan NH4H2PO4 telah digunakan dan menghasilkan nilai temu balik untuk Cr dan Pb dalam CRMs ditemukan antara 81-91% untuk Cr dan 94-98 % untuk Pb dari nilai sertifikat masing-masing.Katakunci: Sedimen, Pirolisis, Matrix modifiers, Cr, P

Preparation and characterization of calcium oxide from crab shells (Portunus pelagicus) and its application in biodiesel synthesis of waste cooking oil, palm and coconut oil

oai:ojs2.sciencetechindonesia.com:article/3Preparation of calcium oxide from Portunus pelagicus through thermal decomposition for 3 hours at various temperature 700°C, 800°C,900°C,1000°C, and 1100°C. The calcium oxidefrom decomposition was carried out and characterized by X-Ray Diffractometer (XRD), FT-IR spectrophotometer and SEM-EDX analyses. The result of XRD show decomposition Portunus pelagicus at 1000°C have diffraction pattern agree with the CaO diffraction standard with 2θ value  32.4º, 37.5º, 64.3º, and 67,5º. The FT-IR spectrum show vibration of CaO at wavenumber 354.9 cm-1. SEM-EDX data indicated the surface morphology  calcium oxide of Portunus pelagicus more homogen than Portunus pelagicus before decomposition. The decomposition of CaO at 1000°C was applied in the syntesis of biodiesel from waste cooking oil, palm oil, and coconut oil. The biodiesel products  have density  0.8621, 0.8725, and 0.8688 g/cm3. Viscosity are 5.27, 3.71, and 2.45 mm2/s(cst). Acid values respectively are 0.3069, 0.2423 and 0.2100 mg/KOH and Iodine numbers 39.48, 36.12 and 9.24 g I2/100g. All characteristic of biodiesel from waste cooking oil, palm oil, and coconut oil are agree with SNI standard.  The best biodiesel product derived from coconut oil is agree to the parameter value of biodiesel standard.  Keywords: biodiesel. Portunus pelagicus. calcium oxide. catalyst

Kinetic and Thermodynamic Adsorption of Cr(VI) onto Dried Oscillatoria Splendida in Aqueous Solution

Kinetic and thermodynamic adsorption study of Cr(VI) ion in aqueous solutions by dried Oscillatoria Splendida biomass was investigated in the batch system. The Oscillatoria Splendida was isolated and cultured from algae swamp ecosystem in South Sumatera. The adsorption properties of Cr(VI) onto dried Oscillatoria Splendida biomass was studied by the influences of contact time, initial Cr(VI) ion concentration and temperature of reaction. The experimental results were the rate of adsorption followed the second-order kinetic model with the rate of reaction k2 is 0.00181 mg g-1 min-1 and the adsorption thermodynamic agree to the Langmuir’s model with amount of  Cr(VI) removed from aqueous solution increased with increasing  Cr(VI) concentration with the higher adsorption energy was 8.46 kJ/mol at 50 °C

Adsorption of congo red using kaolinite-cellulose adsorbent

Kaolinite was impregnated with cellulose extracted from rubber wood fibers has been done. The product of impregnated kaolinite-cellulose was characterized using FT-IR spectrophotometer. Furthermore, the impregnation results are used as an adsorbent of Congo red. Adsorption of Congo red was also studied the kinetic and thermodynamic parameters. The results of characterization using FT-IR spectrophotometer shows the process of impregnation was successfully conducted. It was indicated that the presence wavenumber at 910.4 - 918.12 cm-1 and 1033.85 cm-1 become 1026.13 cm-1 and the existence of vibration at wavenumber 2931.8 cm-1. The pH of adsorption was adjusted to 4 before the adsorption process. The adsorption process of cellulose impregnated kaolinite shows the rate of adsorption (k) of 0.002 min-1, the adsorption reviews largest capacity (b) at 50 °C was 500 mol/g. The greatest adsorption energy (E) at 40 °C is 11:09 kJ/mol. The enthalpy value (ΔH) and entropy (ΔS) decreased with increasing Congo red dye concentration. Keywords: kaolinite, cellulose, impregnation, Congo re

Preparation, characterization, and thermal stability of B2O3-ZrO2

Synthesis of the borate-based compound with ZrOCl2 to form B2O3-ZrO2 has been conducted. The compound was characterized by FT-IR spectrophotometer, X-ray diffraction, acidity and thermal stability test. The results showed that the FT-IR main vibration spectrum of B2O3-ZrO2 compound has appeared at wave number 401.2 cm-1 for Zr-O bonding vibration, 617.2 cm-1 for B-O-B bonding vibration and 910.4 cm-1 for B-O bonding vibration. The XRD diffraction pattern shows B2O3-ZrO2 compound has an amorphous structure. The FT-IR spectrum after saturated with ammonia and potentiometric titration indicates that the compound of B2O3-ZrO2 has acidic properties with a strong level of acidity. Thermal stability test shows that the B2O3-ZrO2 compounds have high stability on temperature with increasing crystallinity after the compound was heated at 700 °C. Keywords: B2O3-ZrO2, impregnation, thermal stability. &nbsp

Preparation of polyoxometalate compound (NH4)6(β-P2W18O62)/SiO2 by sol-gel method and its characterization

Preparation of polyoxometalate compound of (NH4)6(β-P2W18O62)nH2O supported with silica derived from the hydrolysis of tetraethyl orthosilicate by sol-gel method has been conducted. The compound was synthesized and characterized using FT-IR spectrophotometer, crystallinity using XRD analysis and the determination of acidity via quantitatively and qualitatively. Qualitative analysis was performed using ammonia and pyridine adsorption and quantitative analysis using potentiometric titration. FT-IR spectrum of (NH4)6(β-P2W18O62)nH2O appeared in wavenumber 786.96 cm-1 (W-OC-W), 918.12 cm-1 (W-Oe-W), 964.41 cm-1 (W=O), 1087.85 cm-1 (P-O), 3572.17 cm-1 (O-H),  1404.18 cm-1 (N-H) reinforced with wavenumber 1612.49 cm-1 with show vibration  NH dari NH+, and to  (NH4)6(β-P2W18O62)nH2O/SiO2 appears in wavenumbers 794.67 cm-1 (W-Oc-W), 918.12 cm-1 (W-Oe-W), 1049.28 cm-1 (W=O), 1087.85  cm-1 (P-O), 3564.15 cm-1 (O-H), 470.63 cm-1 (Si-O). Diffraction pattern of (NH4)6(β-P2W18O62)nH2O and (NH4)6(β-P2W18O62)nH2O/SiO2 compound show high crystanillity. The acidic properties showed (NH4)6(β-P2W18O62)nH2O/SiO2 more acidic than (NH4)6(β-P2W18O62)nH2O. Analysis of the effect of temperature on the stability of the compounds polyoxometalate (NH4)6(β-P2W18O62)nH2O/SiO2 show that the temperature of 600ºC the shift in  wavenumbers of the compounds caused by vibration  W=O, W-OC-W,  W-Oe-W has been lost. This shows that at a temperatures of 600ºC on heating can cause changes in the structure of polyoxometalate (NH4)6(β-P2W18O62)nH2O/SiO2. Keywords : (NH4)6(β-P2W18O62).nH2O, Polyoxometalate, SiO

Air Quality Analysis of SO2, NO2 and CO in Palembang City

Population activity which tends to centralized in certain area cause decrease in air quality due to exhaust gas from transportation vehicle. From 2011-2014, Palembang city transport growth 3-5% per year comprise of passenger transportation, buses, truck, motorcycle and special vehicle. The increase of vehicle in Palembang gave the city air pollution potential. Transportation is the main source of air pollution in big city with 70% contribution. Exhaust gas from transport activity consist of 60% CO and 15% incomplete combustion of hydrocarbon such as NOx and Sox. The aim of research is to analyzed air quality in Palembang city. Samples were taken and subject to analysis for SO2, NO2 and CO. Sample location were determined by using purposive sampling. Location was chosen by means of traffic density at least for one hour and took place at Charitas crossroads, Patal intersection, Mesjid Agung circle, Lemabang crossroad and Plaju intersection. Result of analysis showed SO2 level is at range 112-208 mg/Nm3/hour. NO2 level between 45-227 mg/Nm3/hour and CO at range 12.595-18.320 mg/Nm3/hour. All parameter of air quality obtained are below threshold value defined by government regulation (GR) on air quality No 41 year 1999

Calcium oxide from Pomacea canaliculata and Babylonia spirata snails

The preparation of CaO from golden snail (Pomacea canaliculata) and lion snail (Babylonia spirata) through decomposition at various temperature i.e 700o, 800o, 900o and 1000oC during 3 hours has been carried out. Calcium oxide from decomposition was characterized using X-Ray diffractometer.  Furthermore, the characterization was continued using FT-IR spectrophotometer and determination of surface area using BET analysis. The results showed that the optimum temperature for preparation of CaO from  golden snail and lion snail at  900oC with 2q values are: 32.2° , 37.4o , 54o , 64.2o , 67.3° and 32.4°, 37.5°, 67.5 °,  respectively. FT-IR spectra showed characteristic vibrations for the Ca-O in the sample golden snail and lion snail combustion products at a temperature of 900oC. Ca-O absorption of golden snail samples in the wavenumber around 362.62 cm-1 and lion snail seen in wavenumber around 384.76 cm-1 indicating the presence of Ca-O vibration of the metal oxide of preparation. Golden snail and the lion snail combustion at 900oC temperature of each sample which has a surface area of 20.495 m2/g, while the lion snail 17.308 m2/g.  The pore diameter of golden snail 3.753 nm and 11.319 nm of lion snail. All CaO can be categorized as mesoporous material. Keywords: golden snail, lion snail, decomposition, Ca

Thermal Stability and Acidity of Silica Supported Keggin Type Polyoxometalate K4[-SiW12O40]•nH2O

Silica supported polyoxometalate K4[a-SiW12O40]·nH2O was prepared systematically using tetraethyl ortho silicate by sol gel method to form K4[a-SiW12O40]·nH2O/Si. Compound K4[a-SiW12O40]·nH2O/Si was characterized by diffraction, spectroscopic, and acidity  analyses follow by thermal activity test at higher temperature up to 600 oC. Analysis of FTIR spectrum showed all unique vibration of polyoxometalate K4[a-SiW12O40]·nH2O was appeared at wavenumber 800-1000 cm-1 before and after supporting process. Crystallinity of K4[a-SiW12O40]·nH2O and K4[a-SiW12O40]·nH2O/Si were also similar without changing Keggin structure. Compound K4[a-SiW12O40]·nH2O/Si showed higher acidity than K4[a-SiW12O40]·nH2O probably due to Lewis acidity species. Keggin structure of K4[a-SiW12O40]·nH2O/Si was still retained up to 600 oC showing thermal stability of K4[a-SiW12O40]·nH2O/Si at high temperature.Keyword : Keggin polyoxometalate, tetraethyl ortho silicate, thermal stability, acidit

Modification of Cellulose with 4.4 Diaminodiphenylether-O-Hydroxibenzaldehide as Adsorbent and Its Application for Adsorbing Metalic Ion of Cd2+ In Aqueous Solution

This research on the modification of cellulose using 4,4-diaminodiphenylether and o-hydroxybenzaldehyde and its application to adsorb Cd2+ in aqueous solution has been done. The adsorption studies of cellulose and modified cellulose were done by using batch technique. The cellulose and modified cellulose were characterized by FTIR. The FTIR spectra revealed characteristic bands of 1573 cm-1, 1280 cm-1, 3749 cm-1 and 1056 cm-1. It indicates function group of C=N, C=O, O-H and Si-OR bond, respectively. The FTIR spectra of cellulose and modified cellulose which interacted to Cd2+, it were indicated by the shift in wavenumber 3410 cm-1 to 3371 cm-1. This spectral shift indicating Cd2+ bound to OH-group. In this research, interaction between modified cellulose with Cd2+ confirmed by intensities spectral changes at 1620 cm-1. The adsorption capacity and energy from adsorption of Cd2+ ions toward cellulose were 71,43 mg/g and 4,142 kJ/mol, while toward modified cellulose were 55,56 mg/g and 0,13 kJ/mol, respectively. Keywords: cellulose, 4,4-diaminodiphenylether-o-hydroxybenzaldehyde, adsorption, Cd2