Utilization of Raw and Activated Date Pits for the Removal of Phenol from Aqueous Solutions

Activated carbons prepared from date pits, an agricultural waste byproduct, have been examined for the adsorption of phenol from aqueous solutions. The activated carbons were prepared using a fluidized bed reactor in two steps; carbonization at 700 °C for 2 hours in N₂ atmosphere and activation at 900 °C in CO₂ atmosphere. The kinetic data were fitted to the models of intraparticle diffusion, pseudo‐second order, and Lagergren, and followed more closely the pseudo‐second‐order chemisorption model. The isotherm equilibrium data were well fitted by the Freundlich and Langmuir models. The maximum adsorption capacity of activated date pits per Langmuir model was 16 times higher than that of nonactivated date pits. The thermodynamic properties calculated revealed the endothermic nature of the adsorption process. The uptake of phenol increased with increasing initial phenol concentration from10 to 200 ppm and temperature from 25 to 55 °C, and decreased with increasing the solution pH from 4 to 12. The uptake of phenol was not affected by the presence of NaCl salt.     

生物制品用原辅料微生物限度检测方法的验证

目的建立生物制品用原辅料(乳糖、葡萄糖、明胶、淀粉、胰酶、纯化水)微生物限度检查法,并进行验证。方法分别采用平皿法及薄膜过滤法检测上述6种原辅料的微生物限度,并按设立的验证试验方法,在供试品中加入5种标准菌,测定标准菌的回收率。结果大肠埃希菌、金黄葡萄球菌、枯草芽孢杆菌、白色念珠菌和黑曲霉5种标准菌在上述6种原辅料供试品溶液中的平均回收率均大于80%,符合《中国药典》二部(2005版)中要求大于70%的合格标准。结论平皿法适用于检测乳糖、葡萄糖、明胶、淀粉、胰酶等原辅料的微生物限度,薄膜过滤法适用于检测纯化水的微生物限度。     

釉用原料的选择及研究

就釉配方确定过程中如何确定釉式和正确选择釉用原料作了论述并提出了自己的看法.     

活性炭纤维在吸附领域的应用

活性炭纤维是一种新型高效吸附材料。本文阐述了活性炭纤维的结构与吸附性能间的关系，并介绍了它在吸附领域的应用。     

磁州窑黑褐彩瓷用原料研究

本文对峰峰地区所产的四种原料的典型样品进行了化学组成、矿物组成测定和差热分析。从所得结果发现峰峰坩石和白坩土中所含主要矿物组成为高岭石类矿物,而白坩土中所含CaO和K_2O是若干量的碳酸钙和白云母等矿物的残留所形成。用于制釉的水治白釉土含有白云母,长石和少量石英、破酸盐。斑花石是一种作为颜料用的褐铁矿,在加熱过程中它会转变为α—Fe_2O_3赤铁矿和磁铁矿,以使瓷器表面产生黑色或褐色花纹。     

改性活性炭用于湿法磷酸脱色的研究

简介了湿法磷酸脱色的现状,开展了活性炭改性及其对染料吸附性能的研究,探讨了活性炭类型、活性炭用量、温度、时间和搅拌速率等因素对湿法磷酸脱色工艺的影响.实验结果表明,采用工业级粉末活性炭(平均粒径0.15 mm)、活性炭用量7.5 g/100 mL、脱色温度55 ℃、脱色时间30 min、搅拌速度300 r/min,磷酸...     

煤质活性炭的原料、预处理及成型技术综述

分析了分别以无烟煤、烟煤、褐煤、泥煤制造活性炭的可能性和预处理技术,介绍了可用来制造煤质活性炭的常用黏合剂及其质量要求,同时,对煤质柱状活性炭、压块活性炭的成型技术进行了全面综述。     

炼化一体化石化企业中乙烯原料的优化利用

介绍了中国石油化工股份有限公司天津分公司优化整合内部资源、拓宽裂解原料来源、实现裂解原料自给自足的情况。详细分析了各种原料的性质和裂解收率情况,对于同类装置增加裂解原料来源具有较好的借鉴意义。     

Thermal Regeneration of Activated Carbons Exhausted with Phenol Compound

Abstract

Two methods, pyrolysis and steam regeneration, were used to investigate the regeneration efficiencies of two types of activated carbons that were exhausted by the phenol compound in the liquid phase. NaOH titration and temperature program deposition indicated that the two carbons exhibit different surface acidities, oxygen group distributions, and oxygen populations on the carbon surface. After treating by pyrolysis and steam regeneration, the surface recovery of spent carbons gradually increased with the regeneration temperature. Pyrolysis at 700?900°C cannot completely remove all phenol molecules from the spent carbons, thereby having a lower surface recovery than steam regeneration. Comparing the two methods, steam regeneration is an efficient method in not only recovering the porosity, but also enlarging and deepening the pore structure of carbons. In comparison with the two carbons, the higher oxygen population on the carbon surface would decrease the surface recoveries and cause a more serious carbon weight loss. This could be attributed to the fact that a greater amount of surface groups would promote the possibility of chemisorbed fraction, thus leaving more degradation species in the pores. This study would shed one light on how oxygen groups existed on carbon surface act as cracking sites in diminishing the removal efficiency.     

Systematic Approach to Quantify Adsorption and Biodegradation Capacities on Biological Activated Carbon Following Ozonation

The goal of this research was to develop a systematic approach to quantify adsorption and biodegradation capacities on biological activated carbon (BAC). The role of absorption and biodegradation on BAC was studied using a continuous column. Several media, i.e., granular activated carbon (GAC), seeded glass bead and seeded GAC, and a target compound (p-hydroxybenzoic acid) were selected. Before breakthrough, the effluent of the GAC column contained a small amount of p-hydroxybenzoic acid that contributed the greatest amount of organic carbon to the effluent of the glass bead column, which suggests that adsorption should be the prevailing mechanism for removal the p-hydroxybenzoic acid, and biodegradation should be responsible for reducing the ozonation intermediates. Also, the bioactivity approach (biomass respiration potential, BRP) of BAC can not only reveal the importance of biodegradation mechanisms for the intermediates of ozonation, but also quantify the extent of the adsorption or biodegradation reaction occurring on BAC.     

Kinetic and Statistical Studies of Adsorptive Desulfurization of Diesel Fuel on Commercial Activated Carbons

Diesel fuel desulfurization by different commercial activated carbons was studied in a batch adsorber. Experiments, carried out to determine the sulfur adsorption dependency on time, were used to perform kinetic characterization and to screen the best performing activated carbon. The equilibrium characterization of the adsorption process was also performed. The statistical study of the process was undertaken by way of a two‐level one‐half fractional factorial experimental design with five process parameters. Individual parameters and their interaction effects on sulfur adsorption were determined and a statistical model of the process was developed. Chemviron Carbon SOLCARBTM C3 was found to be the most efficient adsorbent. The kinetic pseudo‐second order model and Freundlich isotherm are shown to exhibit the best fits of experimental data. The lowest achieved sulfur concentration in treated diesel fuel was 9.1 mg kg^–1.     

灰分对蜂窝活性炭性能的影响

采用恒温搅拌法和恒温超声波振荡法酸解神府煤的灰分,通过电子万能材料试验机和BET分析了灰分对蜂窝活性炭机械性能和吸附性能的影响。实验结果表明,恒温超声波振荡法酸解灰分的效果好,组成灰分的无机盐对蜂窝体机械性能的提高具有促进作用,但对其吸附性能的提高则有阻碍作用。     

超低氯化汞/掺氮活性炭复合材料的制备及其催化性能研究

以乙二胺为氮源,通过热处理制备氮掺杂的活性炭(NAC).以NAC为载体、HgCl2为活性组分采用超声辅助等体积浸渍法制备超低氯化汞/氮掺杂活性炭(HgCl2/NAC)催化剂.通过傅里叶变换红外光谱(FTIR)、粒度分析、X射线光电子能谱(XPS)和N2吸附脱附对材料的官能团、粒径、组成元素和孔结构等进行表征,并考察复合...     

Removal of Color and Organic Matter in Industrial Phosphoric Acid by Ozone: Effect on Activated Carbon Treatment

Industrial phosphoric acid at 42-45% P₂O₅ and containing organic matter (OM) in the range of 220 mg/L to 300 mg/L is treated by combined ozonation and activated carbon. Ozonation alone removes the initial dark color of the acid and eliminates the organic content. Adsorption on activated carbon alone can reduce OM levels by 80% for more than 25 g/kg P₂O₅. We find that a preozonation noticeably enhances activated carbon efficiency and reduces its specific consumption. Isoconversion curves are plotted in specific ozone and activated carbon ratio space.     

Chemical Surface Characterization of Activated Carbons by Adsorption Excess of Probe Molecules

Activated carbons are one of the most common industrial adsorbents in liquid‐phase applications. It is known that the surface groups of the activated carbon can have a significant influence on the adsorption process from the liquid phase. Therefore, it is desirable to measure surface groups on activated carbons. This opens up the possibility to use group‐contribution methods to model and predict adsorption isotherms. An idea is presented to characterize the inner surface of activated carbons by three types of surface groups: aromatic, polar, and nonpolar surface groups. The amounts of these surface groups were calculated from excess adsorption isotherms of probe molecules on ten activated carbons. This lays the groundwork for further simulation studies of liquid‐phase adsorption using group‐contribution methods.     

Activated Carbons from Lignin: Their Application in Liquid Phase Adsorption

Abstract

The extent of the methylene blue (MB) adsorption from an aqueous solution is a convenient indicator in the evaluation of activated carbons. The adsorption of MB (cationic dye) from aqueous solution has been studied using twenty activated carbons. The activated carbons were prepared from acid‐precipitated eucalyptus kraft lignin following a two‐step process consisting of CO₂ partial gasification after carbonization in N₂ atmosphere. The adsorbed amount was studied as a function of the contact time, temperature, pH, concentration of adsorbate, and burn‐off of the activated carbons. The equilibria results obtained in a batch contactor were fitted by the Langmuir equation. The calculated values of ΔG demonstrate that the adsorption of the dye onto these activated carbons occurs by physical adsorption. Both the apparent values of ΔH and ΔS are positive, indicating that the adsorption process is endothermic and can produce spontaneously in our experimental conditions. The kinetic study was developed using a second‐order exponential decay equation and the results were correlated using the Lagergren first‐order equation relative to the concentration on the solid phase. The intraparticle diffusion coefficients have been estimated on the basis of an internal diffusion controlling mechanism for the net adsorption rate.     

活化温度对无灰煤基活性炭结构及性能的影响

以无灰煤(HPC)为原料,KOH为活化剂,采用直接活化法制备无灰煤基活性炭(HAC),并在不同活化温度下探究HAC孔结构的衍化规律。结果表明:活化温度较低时,活化过程表现为无规则碳的烧失,同时微晶单元参与反应,片层明显减小,主要形成0.5 nm以下的微孔,以开孔作用为主。随活化温度的升高,KOH刻蚀微晶结构加剧,以扩孔作用为主,孔径大于0.5 nm的孔居多,同时发展超微孔和中孔。将HAC作为电极材料应用于水系双电层电容器(EDLC)时,其显示出优异的电化学性能,在电流密度为50 mA/g时的比电容达258.2 F/g,在电流密度为5000 mA/g时的比电容保持率在80%以上。研究还发现,EDLC的比电容随HAC电极中0.5 nm^1.5 nm微孔的增加而增大。     

化工产品原料消耗的核算及分析

结合化工生产的特殊性,分别提出了两个原料消耗核算体系;论述了以表格形式系统地核算原料消耗的原理和程序;对两个核算体系进行了分析和比较。     

Last Decade of Research on Activated Carbons as Catalytic Support in Chemical Processes

This review is devoted to the application and knowledge developed in the past 10 years in the area of chemical processes catalyzed by activated carbon supported catalysts. Activated carbons are well known for their catalytic properties and for being used as support in heterogeneous catalysis. The supported catalysts have been successfully used in the chemical industries for long time. In the last decade, carbon supported catalysts have opened the door for new chemical catalytic processes based on their intrinsic features. However, fundamental understanding of molecular structure-reactivity relationship of these carbon materials remains unexplored. Futures advances in all areas may be possible through combined experimental and theoretical approaches.     

Ozone and Activated Carbon for Tertiary Wastewater Treatment

Preozonation of biologically or physically–chemically treated wastewater effluents, followed by passage through granular activated carbon (GAC) for tertiary wastewater treatment was studied at the Duck Creek Wastewater Treatment in Garland, Texas. Whereas the average period of operation for the GAC before exhaustion without ozone pretreatment was 70 days, pretreatment with ozone or with oxygen alone extended GAC operation to at least 480 days, withoutexhaus–tion. Effluent streams consistently metapplicable discharge standards during this period of time, without the necessity of regenerating the GAC.