Pre‐concentration of trace amount of bisphenol A in water samples by palm leaf ash and determination with high‐performance liquid chromatography

Palm leaf ash was characterized and used as low‐cost adsorbent for solid‐phase extraction and preconcentration of bisphenol A (BPA) in real water samples. Analysis of BPA was carried out using HPLC involving Eurospher 100–5‐C₁₈ (25 cm × 4.5 mm, particle size 5 μm) column and water–acetonitrile (40:60, v/v) as mobile phase. The adsorption was achieved quantitatively at a pH of 6 with elution by 3 mL acetonitrile. The limits of detection and enrichment factor were 0.02 μg L^?1 and 333, respectively. Under optimum conditions the relative standard deviation (RSD) was 2% (n = 10). Comparison of qualification criteria of presented preconcentration procedure with other research indicated that palm leaf ash adsorbent was better than many of the adsorbents in terms of cost and reusability. Also, the limit of detection, precision and enrichment factor were comparable and even better than the previously reported methods. Finally, the efficiency of method was computed by determination of trace amounts of BPA in sea, river, mineral and tap waters with recoveries of 93.3–105.5% and RSDs of 0.61–3.12%.. Briefly, the developed solid‐phase extraction and Preparative layer chromatography (PLC) methods may be used for bisphenol A monitoring in any environmental water sample. Copyright © 2016 John Wiley & Sons, Ltd.     

基于波长选择的手掌静脉采集系统研究

手掌静脉成像是手掌静脉识别的难点,设计了一种在拍摄全手的情况下能够采集到较清晰手掌静脉图像的低成本多波段采集系统,并分别在760 nm,850 nm,890 nm和960 nm四种单波长及两两组合的近红外光源下采集手掌静脉,总样本数为2500幅手掌静脉图像,然后利用提取的有效区域中手掌静脉平均灰度与非手掌静脉平均灰度的比值为波长选择标准对图像质量进行比较,最后选择在760 nm和960 nm混合波长下采集手掌静脉。     

Synthesis of Biodiesel from Palm Oil in Capillary Millichannel Reactor: Effect of Temperature,Methanol to Oil Molar Ratio,and KOH Concentration on FAME Yield

Application of microtube reactor for the continuous synthesis of biodiesel has been widely studied due to excellent performance in liquid-liquid phase reaction. In order to commercialize biodiesel production, integration of microtube reactor is highly recommended. Therefore, in this study, synthesis of biodiesel was carried out in capillary millichannel reactor with inner diameter of 1.59 mm using methanol and potassium hydroxide (KOH) as base catalyst with palm oil as a feedstock. The influences of reaction temperature, methanol to oil molar ratio, and KOH concentration on the production of fatty acid methyl ester (FAME) were examined. The highest FAME yield was achieved at 60 ˚C with 23:1 methanol to oil molar ratio and 5 wt% of KOH concentration.     

Kinetic Study on Pyrolysis of Extracted Oil Palm Fiber. Isothermal and non-isothermal conditions

Pyrolysis of extracted oil palm fibers under isothermal and non-isothermal conditions was carried out in a thermogravimetric analyzer. Isothermal curves showed that increasing pyrolysis temperature resulted in a faster pyrolysis and a higher conversion of oil palm fibers into gaseous products. Raw material sizes (below 1.0 mm) had insignificant effects on the isothermal pyrolysis, but the fibers with a size fraction of 1.0 to 2.0 mm resulted in a lesser conversion. Two-step reactions were found in the non-isothermal pyrolysis as evidenced by the presence of two peaks in the derivative thermogravimetry curves. Raw material sizes had no obvious effects on the temperature at which the maximum rate of pyrolysis occurred, but affected the rate of sample mass loss. For the low and high temperature regimes, a three-dimensional diffusion mechanism and a first-order of reaction mechanism respectively were used to describe the non-isothermal pyrolysis kinetics of extracted oil palm fibers. This revised version was published online in July 2006 with corrections to the Cover Date.     

Adsorption of cadmium and lead from palm oil mill effluent using bone-composite: optimisation and isotherm studies

The adsorption of Cd and Pb ions from palm oil mill effluent on a mesoporous-activated cow bone composite powder has been investigated. Adsorbent was developed from cow bones, coconut shells and zeolite. The composite examined in the present work has a BET surface area of 248.398 m²/g. The optimisation of the removal efficiency of the heavy metals was investigated using central composite design and analysed using response surface methodology. The analysis of variance of the quadratic model signified that the model suitably predicted the uptake of the heavy metal ions at a 95% confidence level. The optimal operating condition was recorded at pH 4, 50 rpm, within 24 h and 1 mm of particle size and 12.5 gL^?1 of adsorbent dosage. The characteristics of the composite were investigated using the Fourier transform irradiation. The morphology and chemical composition of composite was examined using the scanning electron microscopy equipped with energy dispersive x-ray. Characterisation study was conducted before and after the adsorption process. The results obtained illustrated that the removal of cadmium and lead from POME was influenced by the functional groups available on the surface of the composite. The carboxyl and hydroxyl groups are mainly responsible for the removal of cadmium and lead through chelating process. The point of zero charge (pH_pzc) revealed that the adsorbent contained acidic sites with negatively charge surface which influenced the adsorption process. The experimental data of the heavy metals of Cd and Pb investigated were fitted to the Langmuir and Freundlich models. The result revealed that the adsorption equilibrium data fitted better to the Langmuir model for the adsorption Cd and to the Freundlich model for the adsorption of Pb.     

Exploration on the characteristics of cellulose microfibers from Palmyra palm fruits

To obtain cellulose microfibers from Palmyra palm fruit fibers, a new succession of specific chemical treatments including acidified chlorination, alkalization, and acid hydrolysis have been developed. Cellulose microfibers obtained were characterized by different techniques. The chemical analysis indicated an increase in α-cellulose content and decrease in lignin and hemicellulose for the cellulose microfibers over raw fibers. Fourier transform infrared and ¹³C NMR spectra confirmed the removal of non-cellulosic (lignin and hemicellulose) components after chemical treatments. The X-ray diffraction results revealed that the cellulose I was partly transformed into cellulose II by chemical treatments and the crystallinity index of cellulose microfibers was significantly increased as compared to raw fibers owing to removal of non-cellulosic components. Thermogravimetric analysis results demonstrated that the thermal stability was enhanced noticeably for cellulose microfibers than for the raw fibers. The scanning electron micrographs illustrated cleaner and rough surfaces for the cellulose microfibers when compared to those of raw fibers.     

Extraction of biosilica from date palm biomass ash and its application in photocatalysis

There is an emerging trend in the valorization of biomass waste for the development of value-added products. Date palm biomass is an extensively available bioresource in Saudi Arabia. In date palm farms, the biomass residues are usually burnt, and a lot of ash is generated. Biomass ash is rich in silica, which is a valuable material used in a wide range of applications. This study explores the extraction of pure silica nanoparticles from date palm biomass ash (DPBA) and its application in photocatalysis. A chemical sol–gel method or thermal combustion method was employed for the extraction of silica. The extracted silica nanoparticles were characterized by EDX, FT-IR, XRD, SEM, BET, and TGA. FT-IR spectra of extracted biosilica samples displayed only the characteristic peaks corresponding to the silica functional groups. The chemically synthesized biosilica sample exhibited higher purity (98 %) and higher surface area (376 m²/g) compared to the thermally prepared biosilica samples. The SEM analysis revealed the presence of spherical-shaped silica particles of an average diameter of 93 nm in chemically extracted biosilica and 208 nm in thermally extracted biosilica. The newly extracted biosilica samples were tested for the photodegradation of the bromophenol blue dye in water. The dye degradation efficiency of chemically prepared biosilica sample was 82 % and that of thermally prepared biosilica sample was 74 %. The relatively higher degradation efficiency of BS-chemical could be due to its higher surface area and smaller particle size, and also due to the presence of lots of surface defects in this fully amorphous biosilica.     

Mechanical and acoustical properties of particleboards made with date palm branches and vermiculite

The main goal of this study was to determine the performance of particleboards made from date palm branches (DPB, Phoenix dactylifera), as a low-value raw material and expanded vermiculite (VER), as a natural inorganic filler. DPB is underutilized abundant byproduct in southern parts of Iran. For the purpose of evaluation, compositions of DPB and VER at different mixture rates were compared for some properties. Variable parameters were: number of particleboard layers (single- and three-layer), VER size (micro and nano meter), and VER content (0, 10 and 20 wt%). Other parameters such as resin content (10%), hardener content (2%), pressing time (6 min), board density (0.75 g/cm³), press pressure (35 kg/m²) and press temperature (175 °C) were held constant. Physical properties (thickness swelling (TS), water absorption (WA), and sound absorption coefficient (SAC)), and mechanical properties (modulus of rupture (MOR), modulus of elasticity (MOE), and internal bond strength (IB)) of the boards were determined. Based on the findings of this study, all mechanical properties of the boards slightly decreased when the VER content was increased from 0 to 20 wt%. Analysis of data revealed that the mechanical properties were significantly different among the board types. In general, WA and TS increased with the increase of WER content. The presence of nano VER in the particleboards resulted in higher WA and TS. The SACs of composite boards filled with VER increased as the frequency increased. Nano VER and single-layer boards showed higher SACs in frequency range of 800–1250 Hz. Finally, it can be stated that DPB has potential as replacement fibrous material for particleboard manufacturing and indoor applications.     

棕榈壳焦CO2气化过程中反应性及结构特性研究

850℃下,利用管式炉制备了不同转化率的棕榈壳CO₂气化焦,通过热重分析仪研究了气化焦的CO₂气化反应性,采用比表面积分析、拉曼光谱、X射线荧光光谱和扫描电镜-能谱等分析手段,考察了气化焦孔隙结构、碳组成、矿物元素含量与分布随转化率的变化。结果表明,在CO₂气化过程中,随着转化率的提高,棕榈壳气化焦固定碳的含量逐渐降低,有序化碳的相对含量为0.30~0.33,对气化过程起到一定的抑制作用;灰分含量逐渐增加,但气化反应指数R_s呈现先降低后升高的过程。转化率小于23%时,R_s与气化焦比表面积的变化趋势一致;23%< 转化率< 31%时,R_s基本不变;31%< 转化率< 68%时,比表面积随转化率线性增加,R_s取决于孔隙比表面积、矿物元素催化2个因素的协同作用,当转化率> 56 %时,该催化作用变得明显,同时碳的有序化程度开始降低;转化率> 68%时,R_s主要受矿物元素的催化作用控制。     

The Olefin Reaction between Crude Palm Oil Fatty Acid Methyl Ester (CPO FAME) and Ethylene Using Grubbs II Catalyst

Renewable materials derived from vegetable oils are now widely developed for obtaining green polymers. One of the applications of those polymers is in the field of Enhanced Oil Recovery (EOR) where the polymers are put in the injection wells to increase water viscosity resulting in higher efficiency of oil production. Indonesia is very rich in crude palm oil and therefore, it was chosen as the starting material for polymer synthesis. The objective of this work is to prepare the monomer first, by doing the olefin metathesis reaction between crude palm oil FAME (fatty acid methyl ester) and ethylene. The reaction was carried out using a Grubbs II catalyst in order to obtain methyl 9-decenoate which is used later as the monomer for EOR application. The resulting product was characterized using Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) spectroscopy as well as Gas Chromatography Mass Spectrometry (GC-MS). Based on the functional group analysis, it was found that methyl 9-decenoate has successfully been synthesized.