Adsorptive treatment of phenol from aqueous solution using chitosan/calcined eggshell adsorbent: Optimization of preparation process using Taguchi statistical analysis

Phenol and its derivatives are known to be toxic causing adverse impact on human health and environment. Adsorption utilising waste materials is a cost effective method for abatement of such pollutants. The present study thus aims to remove the phenol from aqueous solutions using chitosan/calcined eggshell adsorbent. Taguchi L₂₇ Orthogonal array design methodology was used for the optimization of preparation variables. The statistical results obtained using ANOVA and S/N ratios showed that adsorption of phenol was significantly influenced by activation temperature (54.90%) and activation time (43.70%) whereas the mix ratio had fairly low impact on the output response (1.14%). The confirmation run in optimum preparation conditions of temperature (800 ?°C), time (60mins) and mix ratio (1:1) resulted in maximum adsorption capacity (10.82 ?mg/g) which confirmed that the optimization done by Taguchi model was valid and reliable. The characterization of adsorbent prepared under optimum conditions were done using scanning electron microscopy, X-ray diffraction (XRD), and the Fourier transform Infrared spectroscopy (FTIR). Adsorption and kinetic studies manifested that the adsorption phenomenon onto prepared adsorbent is illustrated well by linear Langmuir isotherm and pseudo second order kinetics.     

Quantitative HPLC of pigments of irregularly coloured eggshells: application to aliquots of powdered shell from quail

Twelve quail eggshells from farmed Coturnix coturnix japonica were separately ground to fine powder and two aliquots of each (average weights 13.86 mg and 51.90 mg) were extracted with formic acid. Biliverdin (38–284 pmol/mg) and protoporphyrin (841–1666 pmol/mg) were measured by HPLC. There was good agreement between the values for the corresponding samples and with those for two entire eggshells from the same source. The preparation of a homogenate as a powder from heterogeneously pigmented eggshells has the advantage that not all of the sample needs to be initially extracted for analysis and residual material can be stored in a stable form and used for repeat measurements and for longitudinal studies. Copyright © 2012 John Wiley & Sons, Ltd.     

调质鸡蛋壳的脱硫性能

用NaOH、C_2H_5OH、Na_2CO_3和NaCl等对鸡蛋壳进行了调质,研究调质鸡蛋壳的脱硫效果,结果表明最佳的蛋壳调质剂为NaOH,经NaOH调质后蛋壳粉的最佳固硫温度为1 000℃,最佳,n(Ca):n(S)=2:1.实验比较了同一条件下NaOH调质蛋壳固硫剂、蛤壳和蚝壳等天然固硫剂在1 000℃下的脱硫效果,结果表明NaOH调质蛋壳的脱硫率最高,达到88.1%.SEM实验结果表明,氢氧化钠不但可以除去蛋壳的生物膜还能改善蛋壳表面的微观结构,有效地提高了蛋壳的脱硫率.     

乌龟卵壳结构的研究

本文对乌龟卵壳在扫描电镜下的微观结构进行了研究。乌龟卵壳主要由钙质层与壳膜组成。钙质层由霰石状态的碳酸钙晶体组成,可分为许多个壳单位,每个壳单位由同一中心辐射出来的针状晶体构成。卵壳的外表面具有一定的饰纹,有些部位还分布有纵横交错的有机纤维和块状的有机物质。壳膜由多层网状纤维组成,没有内、外壳膜之分.龟卵在孵化过程中不形成气室。同时对孵化前后龟卵壳的结构进行了对比研究。     

Eggshell Nanosheets: Synthesis,Properties, and Their Forensic Applications in Latent Friction Ridges Development

Since waste materials are used to identify, individualize, and evaluate evidence like fingerprints, palmprints, footprints, etc. that are found at a crime scene, they have a substantial impact on the field of forensic science. Many waste powders have recently been employed in fingerprint recognition. Nanosheets made up of eggshells have been put forward as an application in friction ridge development. Eggshell is a biochemical substance made up of chemical compounds like calcium carbonate, which is considered as a waste product. For the formation of an eggshell nanosheet (ESN), shells are dried and crushed into a fine powder and to get this powder in the form of a nanosheet, the Ball milling technique is used. The synthesis of pure ESN is confirmed by Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) techniques. The size of nanosheets ranged from 30 to 90 nm as shown in SEM images. Developed powder is then used for the application of fingerprint development and it provides excellent results on all porous, non-porous, and semi-porous surfaces. Thus, this newly synthesized ESN powder can be used as a significant powder method in latent fingerprint technology.     

蛋壳型Ni/Al2O3催化剂的制备研究

随着生产的发展,工业装置日趋大型化,催化剂内表面利用率?宏观选择性?阻力降等问题日益引起人们的注意。为了提高催化剂的利用率,人们开始关注活性组分非均匀分布催化剂[1-2]。活性组分非均匀分布催化剂分为蛋壳型?蛋白型和蛋黄型三种典型类型[3]。蛋壳型催化剂能减少贵金属活性组分的用量,提高不可逆串联反应过程中中间产物的选择性[4,5];除此外蛋壳型催化剂抗自身中毒的性能较好[6-9]。本文用几种方法来制备蛋壳型催化剂,并对其进行了比较,由实验数据和理论分析得出:刷涂沉淀法能使活性组分N i最集中分布在活性氧化铝球载体表面,制得活性…     

纳米粒子在生物膜上的成核和生长

通过室温液相浸渍优化技术,新鲜的蛋膜材料依次在醋酸铅和硒代硫酸钠溶液中进行浸渍处理,在蛋膜载体上均匀析出硒化铅纳米晶粒并组装成一定形状的纳米团簇.并用X-射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)和透射电镜(TEM)对产物形貌和结构进行了表征.     

鸡蛋壳制备葡萄糖酸钙的研究

葡萄糖酸钙是一种溶解度高,生理宽容性大的钙营养剂和抗过敏药,广泛用作食品添加剂及医药制剂供口服或静脉注射.目前常用的生产方法主要是生物发酵法,其缺点是工艺复杂, 生产周期长且易造成污染.本研究以葡萄糖酸δ内酯作为葡萄糖酸的来源,利用蛋壳中所含高达93%的CaCO3[1]进行中和反应制备葡萄糖酸钙,探索了一条变废为宝,工艺简单,成本低,污染小的葡萄糖酸钙生产路线.     

Multi-Class Procedure for Analysis of 50 Antibacterial Compounds in Eggshells Using Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry

In this work, for the first time, Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry (UHPLC–MS/MS) method was developed for qualitative and quantitative analysis of veterinary antibiotics (cephalosporins, diaminopyrimidines, fluoro(quinolones), lincosamides, macrolides, penicillins, pleuromutilins, sulfonamides, tetracyclines, and sulfones) in hen eggshells. The sample preparation method is based on a liquid–liquid extraction with a mixture of metaphosphoric acid, ascorbic acid, EDTA disodium salt dihydrate, and acetonitrile. The chromatographic separation was performed on Luna^® Omega Polar C18 10 column in gradient elution mode and quantitated in an 8 min run. Validation such as linearity, selectivity, precision, recovery, matrix effect, limit of quantification (LOQ), and limit of detection (LOD) was found to be within the acceptance criteria of the validation guidelines of the Commission Decision 2002/657/EC and EUR 28099 EN. Average recoveries ranged from 81–120%. The calculated LOQ values ranged from 1 to 10 µg/kg, the LOD values ranged from 0.3 to 4.0 µg/kg, depending on analyte. The developed method has been successfully applied to the determination of antibacterial compounds in hen eggshell samples obtained from different sources. The results revealed that enrofloxacin, lincomycin, doxycycline, and oxytetracycline were detected in hen eggshell samples.