scholarly journals Factors Affecting the Adsorption of Trivalent Chromium Ions by Activated Carbon Prepared from Waste Rubber Tyres

2017 ◽  
Vol 2 (3) ◽  
pp. 1660-1664
Author(s):  
Sylvia E. Benjamin ◽  
Muhammad Ashfaq Sajjid
Keyword(s):  
Activated Carbon ◽  
Trivalent Chromium ◽  
Factors Affecting ◽  
Chromium Ions ◽  
Waste Rubber

Examination of Conditions for the Determination of Carbamate Pesticides in Soils

1992 ◽  
Vol 57 (8) ◽  
pp. 1632-1638 ◽  
Author(s):  
Věra Tatarkovičová ◽  
Zdeněk Stránský
Keyword(s):  
Activated Carbon ◽  
Solvent Extraction ◽  
Soil Type ◽  
Extraction Procedure ◽  
Purification Procedure ◽  
Factors Affecting ◽  
Carbamate Pesticides ◽  
Rp Hplc ◽  
Extracting Solvent

The procedure for the determination of carbamate pesticides in soil was optimized. The following factors affecting the final results were investigated: extracting solvent, extraction procedure, extract purification procedure, and soil type. Triple extraction with acetone and purification of the extract on a two-stage purification column containing an activated carbon-silica gel 1+1 mixture were found optimal. The extracts after treatment were analyzed by RP-HPLC with UV detection. The method developed allows carbamate pesticides in soil to be determined at concentrations in excess of 30 μg kg-1.

Analysis of the Factors Affecting the Instrumentation of the Technological Process of the Activated Carbon Material Production

2022 ◽  
pp. 20-30
Author(s):  
A.A. Popova ◽  
I.N. Shubin
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Carbon Material ◽  
Mutual Influence ◽  
Chemical Activation ◽  
High Specific Surface Area ◽  
Laboratory Research ◽  
High Porosity ◽  
Gas Purification ◽  
Factors Affecting

The article discusses significance of the development of activated carbon materials with a high specific surface area and high porosity. The features of the course of chemical activation and the factors influencing the characteristics of the obtained material have been established. The main stages of the activation of the carbon material, including the preliminary raw carbon material carbonization, its alkaline activation, and the post-processing of the created material, have been determined. The mutual influence of temperature and flow rate of an inert gas on the characteristics of a carbon material obtained with a BET specific surface in the range of 2550–2700 m2/g is experimentally investigated. The analysis of the obtained results has been carried out. Recommendations are given for reducing ambiguity and uncertainty during the transition from laboratory research to pilot production. The resulting activated carbon material can be used as a sorbent in gas purification systems, gas accumulators and for solving various environmental problems.

Luminescence of Trivalent Chromium Ions in Mullite During Firing of Kaolin

2017 ◽  
Vol 74 (1-2) ◽  
pp. 23-25 ◽  
Author(s):  
A. V. Igo ◽  
A. E. Kozhevin
Keyword(s):  
Trivalent Chromium ◽  
Chromium Ions

scholarly journals Preparation and Characterization of Activated Carbon from Waste Rubber Tires: A Comparison between Physical and Chemical Activation

2015 ◽  
Vol 1107 ◽  
pp. 347-352 ◽  
Author(s):  
Collin Glen Joseph ◽  
Duduku Krishniah ◽  
Yun Hin Taufiq-Yap ◽  
Masnah Massuanna ◽  
Jessica William
Keyword(s):  
Activated Carbon ◽  
Automobile Industry ◽  
Chemical Activation ◽  
Waste Product ◽  
Physical Activation ◽  
Activation Process ◽  
Waste Rubber ◽  
Percentage Yield ◽  
Static Conditions ◽  
Physical And Chemical

Abstract. Waste tires, which are an abundant waste product of the automobile industry, were used to prepare activated carbon by means of physical and chemical activation. A two-stage process was used, with a semi-carbonization stage as the first stage, followed by an activation stage as the second stage.All experiments were conducted in a laboratory-scale muffle furnace under static conditions in a self-generated atmosphere. During this process, the effects of the parametric variables of semi-carbonization time (for the physical activation process), activation time and temperature and impregnation ratios (for the chemical activation process) on the percentage yield were studied and compared. Varying these parametric variables yielded interesting results, which in turn affected the adsorption process of 2,4-DCP, which was the simulated pollutant in aqueous form. The optimized percentage yields of activated carbon that were obtained were 41.55% and 44.88% ofthe physical and chemical activation treatment processes respectively.Keywords: Physical activation, chemical activation, waste rubber tires, 2,4-dichlorophenol, activated carbon.

scholarly journals Estimation and Removal of Chromium Ions from Tannery Wastes Using Zeolite-3A

1998 ◽  
Vol 16 (3) ◽  
pp. 153-161 ◽  
Author(s):  
Hajira Tahir ◽  
M. Saleem ◽  
M. Afzal ◽  
H. Ahmad ◽  
S.T. Hussain ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Metal Ions ◽  
Low Cost ◽  
Liquid Waste ◽  
Atomic Absorption Spectrophotometry ◽  
Factors Affecting ◽  
Chromium Ions ◽  
Ion Removal ◽  
Sorbent Materials ◽  
Isotherm Equations

The concentration of potentially toxic chromium metal ions in sediments and liquid waste samples from selected tanneries was measured by atomic absorption spectrophotometry after digestion with nitric acid. The data obtained revealed the presence of elevated levels of chromium metal ions in waste samples relative to the NEQS (National Environmental Quality Standards) require-ments. A new process entitled IERECHROM (Ion Exchange REmoval of CHROMium) has been developed for the removal and separation of chromium ions from sediments using zeolite-3A. The factors affecting chromium ion removal include exchanger concentration, pH, shaking time and temperature. The applicability of the Freundlich. Dubinin–Radushkevich and virial isotherm equations to the system has been examined. The thermodynamic parameters °LH0, °LG0 and °LS0 were calculated using the virial isotherm expression. The results suggest that natural aluminosilicates such as zeolite-3A can be utilised as low-cost ion-exchange and sorbent materials because of their selectivities for the removal of chromium ions and various other heavy metals.

Magnetic Fe3O4@C nanoparticles as adsorbents for removal of amoxicillin from aqueous solution

2013 ◽  
Vol 69 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Babak Kakavandi ◽  
Ali Esrafili ◽  
Anoushiravan Mohseni-Bandpi ◽  
Ahmad Jonidi Jafari ◽  
Roshanak Rezaei Kalantary
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Kinetic Models ◽  
High Surface ◽  
High Surface Area ◽  
Order Kinetic ◽  
Magnetic Composites ◽  
Factors Affecting ◽  
Transmission Electron ◽  
Pseudo Second Order

In the present study, powder activated carbon (PAC) combined with Fe3O4 magnetite nanoparticles (MNPs) were used for the preparation of magnetic composites (MNPs-PAC), which was used as an adsorbent for amoxicillin (AMX) removal. The properties of magnetic activated carbon were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Brunaeur, Emmett and Teller and vibrating sample magnetometer. The operational factors affecting adsorption such as pH, contact time, adsorbent dosage, initial AMX concentration and temperature were studied in detail. The high surface area and saturation magnetization for the synthesized adsorbent were found to be 671.2 m2/g and 6.94 emu/g, respectively. The equilibrium time of the adsorption process was 90 min. Studies of adsorption equilibrium and kinetic models revealed that the adsorption of AMX onto MNPs-PAC followed Freundlich and Langmuir isotherms and pseudo-second-order kinetic models. The calculated values of the thermodynamic parameters, such as ΔG°, ΔH° and ΔS° demonstrated that the AMX adsorption was endothermic and spontaneous in nature. It could be concluded that MNPs-PAC have a great potential for antibiotic removal from aquatic media.

Factors affecting trihalomethane formation and speciation during chlorination of reclaimed water

2015 ◽  
Vol 72 (4) ◽  
pp. 616-622 ◽  
Author(s):  
Defang Ma ◽  
Baoyu Gao ◽  
Yan Wang ◽  
Qinyan Yue ◽  
Qian Li
Keyword(s):  
Wastewater Treatment ◽  
Activated Carbon ◽  
Correlation Coefficient ◽  
Contact Time ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Reclaimed Water ◽  
Neutral Condition ◽  
Municipal Wastewater Treatment ◽  
Factors Affecting

A hybrid process with membrane bioreactor (MBR) and powdered activated carbon (PAC), PAC/MBR, was used for real municipal wastewater treatment and reuse. The roles of chlorine dose, contact time, pH and bromide in trihalomethane (THM) formation and speciation during chlorination of the reclaimed water were investigated. Total trihalomethane (TTHM) yield exponentially increased to maximum with increasing chlorine dose (correlation coefficient R2 = 0.98). Prolonging substrate chlorine contact time significantly promoted TTHM formation. Less than 40% of THMs formed in the first 24 h, indicating that the PAC/MBR effluent organic matters were mostly composed of slow-reacting precursors. Increasing pH and bromide concentration facilitated THM formation. Higher chlorine dose and contact time enhanced chloro-THM formation. The bromo-THM formation was favored at near neutral condition. Despite the variation of chlorine dose, contact time and pH, the yield of THM species in order was usually CHCl3 > CHBrCl2 > CHBr2Cl > CHBr3. However, THM speciation shifted from chlorinated species to brominated species with increasing bromide concentration.

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