Contain all the articles from this issueICEEM/01 -- Environmental Engineering SectionThermodynamic and kinetic study of gas desulphurization by adsorption on zeolites  Ion Untea, Dan Brasoveanu, Madeleine Dancila, Szidonia Bocskor Mixed oxides derived from vanadium substituted layered double hydroxides as catalysts precursors for SO2 oxidationGabriela Carja, Ionel Popa, Gabriela Ciobanu, Nicolae Aelenei The impact of energy production on environment in RomaniaCarmen Zaharia, Mioara Sur...
Autori:
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25168

AbstractThe adsorption characteristics of n-hexane vapors from gaseous stream onto two types of hypercrosslinked polymeric resins (MN 202 and MN 250), and a bituminous granular activated carbon (AC 20) was investigated. The n-hexane influent concentration ranged from 2100 to 4500 ppm and the adsorption processes were performed at 30, 40 and 50 ?C. Thermodynamic potentials ?H, ?S, and ?G and isosteric heats of adsorption were calculated from experiment performed at different temperatures (30-50?C...
Autori: Adela Marilena Buburuzan, Cezar Catrinescu, Matei Macoveanu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25393

Abstract The presence of heavy metals in the environment is a major concern due to their non-biodegradability, bioaccumulation tendency, persistence in nature and toxicity to many life forms. Different treatment techniques for wastewater laden with copper have been developed in recent years to decrease the amount of wastewater produced and to improve the quality of the treated effluent. All techniques have their advantages and limitations in application. One of the most used techniques to rem...
Autori: Petru Bulai, Catalin Balan, Camelia Scripcariu, Matei Macoveanu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25531

Abstract The goal of the study was to investigate the sorption behavior of Acid Orange 7 (C.I. 15510) onto soil collected from Iasi area (Romania). The sorption isotherm, kinetic and thermodynamic studies were performed by batch mode. The effects of experimental parameters such as contact time, pH value (2-12) and temperature (20 - 400C) have been studied. Also the influence of initial dye concentration (10 - 100 mg/L) and sorbent dosage (from 5 g L-1 to 150 g L-1) were studied. It was found ...
Autori: Camelia Smaranda, Dumitru Bulgariu, Maria Gavrilescu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25566

Abstract:A thermodynamic model for accurately predicting the overall efficiency and power output of a solar assembly using a Stirlingengine is presented. It is based on the application of the First Law of Thermodynamics for Processes with Finite Speed and usesthe Direct Method. The proposed model could also be used to better design receivers that concentrate the solar radiation and toproperly size the receiver cavity for a dish solar concentrator. Examples of the optimization of the performance ...
Autori: Alexandru Dobrovicescu, Camelia Stanciu, Dorin Stanciu, Georgiana Tirca-Dragomirescu, Monica Costea, Stoian Petrescu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25763

Abstract:The aim of this paper is to propose a set of thermal models for the regenerator by taking into account the time dependent heattransfer processes, and to combine them with the thermodynamic lumped description of the solar Stirling engine, accordingly torecent description.By using analytical and numerical methods, the optimum power of the engine is sought when various constrains (or not) areconsidered, particularly fixed heat transfer rate available at the source.A sensitivity analysis of...
Autori: Alexandru Dobrovicescu, Andreea Marin, Catalina Dobre, Georgiana Tirca-Dragomirescu, Michel Feidt, Monica Costea
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25767

AbstractThe performance of four low cost Iraqi clays, bentonite (BT), kaolinite (KT), attapalgite (AT) and flint (FT) to remove lead ionsfrom aqueous solutions by adsorption was investigated. Batch experiments were carried out at pre determined equilibration time,adsorbent dosage, solution pH, particle sizes, ionic strength, initial lead ions concentration and temperature. Adsorption of Pb2+ions was strongly affected by pH and best adsorption is achieved at pH 4.5. The systems were investigated ...
Autori: Najwa I. Abdulla
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26086

AbstractBehaviors of adsorption of di-n-butyl phthalate (DBP) on humic acid and the effects of temperature on these processes are studied by solid phase extraction-HPLC method. The results show that the adsorption amounts of DBP increase with increasingequilibrium-concentrations of DBP. Such results could be well described by Langmuir equation. The maximum adsorptionamount (Qmax) and adsorption constant (k) at 35oC were both lower than those at 25oC. Thus, high temperature is unfavorable to the ...
Autori: Zhi-dang Yang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26162

AbstractIn this work, fruit shell of Cocos nucifera (FSCN) treated with H3PO4 has been tested as a low cost adsorbent for the removal of methylene blue (MB) from aqueous solution in batch and column process. The adsorption of MB onto FSCN was affected by the initial solution pH, dye concentration, temperature, column internal diameter and adsorbent dose. The adsorption equilibrium data was fitted well to the Langmuir model and the maximum adsorption capacity was found to be 20.74 mg/g at 40şC. K...
Autori: Pijush Kanti Mondal, Rais Ahmad, Rajeev Kumar
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26274

AbstractThe adsorption potential of 10 wt.% COOH/TUD-1 material for removing Cd2+ from aqueous solutions was investigated via thebatch technique, and the effects of pH, temperature and contact time were studied. Experimental data showed that the maximumCd2+ adsorption, 90%, occurred at pH 6. The adsorption equilibrium was reached within 35 min for 10 wt.% COOH/TUD-1. Theadsorption mechanism was investigated in terms of its thermodynamics and kinetics. The adsorption data were fitted using theLan...
Autori: Nabila Bensacia
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26558

AbstractGraphene oxide (GO) was prepared from expandable graphite by a modified Hummers’ method and characterized by TEM,XRD, FTIR, and Raman spectroscopy. The batch adsorption experiments were carried out to study the effect of variousparameters, such as the initial concentration, adsorbent dosage, initial pH, contact time and temperature on adsorption propertiesof cationic red X-GRL onto GO. The Langmuir and Freundlich models were used to fit the experimental data of adsorptionisotherms. The k...
Autori: Jiankun Sun
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26570

Abstract A model of an irreversible combined thermionic-thermoelectric generator with internal and external irreversibilities is established in this paper. The performances of the combined generator, in which the heat transfers obey radiative heat transfer law, are analyzed and optimized by using the combination of finite time thermodynamics and non-equilibrium thermodynamics. The general expressions for power output and efficiency versus drop voltage are derived. The influence of finite rat...
Autori: Zemin Ding
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26624

Abstract The present work investigates the performance of Cristal-RightTM CR100 zeolite based on the equilibrium and thermodynamics water softening process. The commercial zeolite was characterized by scanning electron microscopy combined with energy dispersive X-ray spectroscopy and FT-IR spectroscopy. The equilibrium performances of zeolite were evaluated by the sorption capacity of calcium cations from calcium chloride solutions varying the calcium concentrations corresponding to moderate...
Autori: Liliana Lazăr
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26670

Abstract Locally sourced clay from Kuala-Kangsar town in Perak state Malaysia was used in both its raw (RKKC) and modified (MKKC) form as adsorbents for the removal of methylene blue (MB) from synthetic textile wastewater in batch adsorption process. The raw clay was modified through H2SO4 acid treatment, Al(OH)3 ion exchange, calcinations and then molded into beads before freeze drying. The BET surface areas of RKKC and MKKC were 11 and 100 m2/g, respectively; their elemental analysis and ...
Autori: Manase Auta
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26717

Abstract Maximum removal (94±1.2%) of 2, 4 dichlorophenol (50 mg.dm-3) was achieved on silica with agitation of 4 hours, at pH 8 and 42°C. The positive enthalpy (ΔH) and negative free energy values (ΔG315K) suggested the endothermic and a spontaneous nature of sorption. The free energy of the process at all temperature was negative and increased with the increase in temperature. The values of free energy suggested a spontaneous process where the spontaneity decreased w...
Autori: Abdul Ghaffar
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26718

Abstract The aim of this study is to evaluate adsorption kinetics, isotherms and thermodynamic parameters of anionic textile dye (Acid Red 88) onto montmorillonitic clay from aqueous solutions. The parameters of pH, initial dye concentrations, temperature, and the adsorbent dosage were investigated experimentally. Four kinetic models including pseudo-second order, pseudo-nth order, Bangham’s equation and double exponential equation (DEE) were selected to follow the adsorption process. ...
Autori: Sedef Dikmen
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26731

Abstract Chitosan and keratin were tested as low cost biosorbents to remove phenol from water solutions at variable temperature (20- 50°C), initial phenol concentration (10-90 mg L-1) and pH (5.0-10.0), and fixed biosorbent dosage (10 g L-1). The pseudo-second order kinetic model exhibited the best fit to the experimental data and allowed estimating theoretical values of sorption capacity of 4.51 mg g-1 with keratin and 2.87 mg g-1 with chitosan. Equilibrium isotherms, described at best ...
Autori: Attilio Converti
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26743

Abstract On the basis of a generalized irreversible Carnot heat engine (GICHE) model with the losses of heat resistance, heat leakage and internal irreversibility, the local stability of the heat engine at the maximum ecological function (MEF) is studied with Newton’s heat transfer law between working fluid and heat reservoirs. It is derived that a general expression of relaxation time described as stability of the system refers to heat capacity C, overall heat transfer surface area F,...
Autori: Lingen Chen
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26859

Abstract Solar photovoltaic (PV) system performance parametrically depends on climatic, operating and design parameters, and in view of thermodynamics it can be evaluated in terms of energy and exergy efficiencies. In this paper, thermodynamics efficiencies of two different solar PV modules technology i.e. wafer based crystalline silicon and thin-film are evaluated. As a subject, polycrystalline silicon (ASE-100) and amorphous silicon (DS-40), as components of 10 kWp grid-connected PV array ...
Autori: Dani Rusirawan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26899

In this study the immobilized waste black tea (Camellia synensis) was used as biosorbent for the removal and recovery of Al(III) and Cr(VI) ions from the synthetic aqueous solutions. Batch experiments were conducted to optimize the various biosorption parameters that affect the biosorption capacity of immobilized waste black tea. Maximum biosorption capacity was found with a biosorbent dose of 0.1g/100 mL for both metal ions. Optimum biosorption capacity for both Al(III) and Cr(VI) ions was o...
Autori: Haq Nawaz Bhatti
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27004

The discovery of entropy in thermodynamics has set fundamental premises for the study and analysis of the relationship between the entropy law and economic processes, as one of the main objectives of such endeavours was to separate the qualitative aspects from the realm of economics. The law we have chosen to focus on in the present paper states that, in the universe or in isolated structures, entropy increases constantly and irreversibly, thus causing a continuous and unidirectional degradat...
Autori: Ionel Bostan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27179

The present study was aimed at examining the ability of the natural zeolitic tuff from the Zlatokop deposit in Serbia to remove Pb(II) ions from aqueous solutions under various conditions. It has been found that the adsorption proceeds via an ion-exchange reaction in which the Na+ ions from the clinoptilolite phase of the tuff are replaced to a high degree by aqueous Pb(II) ions. The removal capacity of the clinoptilolite at 298 K varies from 78 mg Pb g–1 (for C0 = 100 mg Pb dm–3) to...
Autori: Djordje Stojakovic
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27234

Three modified bentonites, hydroxy-aluminum pillared bentonite (Al(OH)-Bent), cetyl trimethylammonium bromide modified bentonite (CTAB-Bent), and both cetyl trimethylammonium bromide and hydroxy-aluminum modified bentonite (Al(OH)-CTAB-Bent) were prepared and characterized by Fourier transform infrared spectroscopy (FTIR) analysis. Batch experiments were conducted on the adsorption of phenol at different temperatures, pH and initial concentration. The results indicated that adsorption capacity o...
Autori: Xiping Luo
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27481

The potential use of a novel low-cost adsorbent, Eupatorium adenophorum Spreng, as a solution to remove Cr(VI) ions from aqueous was reported. Effects of various regulating parameters, such as pH value of reaction, adsorbent dosage and temperature, were investigated. To fit the adsorption equilibrium data, Langmuir isotherm and Freundlich isotherm were invoked. Additionally, thermodynamic parameters of the adsorption process, such as ΔG, ΔS and ΔH, were also calculated. The res...
Autori: Chen Jin-fa
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27535

In this research, the capability of uranium biosorption by dried biomass of the red algae was investigated in a batch system. For the screening of the most appropriate biosorbent, they were placed in 0.5 mmol/L uranium solution with different pH for 3hrs of contact times. The obtained results showed that the species of the Gracilaria corticata (J. Agardh) are having the maximum rate of the biosorption. Sorption equilibrium was reached within 3hrs of contact time (at pH 4.5), and the results of t...
Autori: Reza Dabbagh
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27596

The adsorption rate and dynamic behavior of the system are important factors as regards the process design and operational control. The aim of this study was to find a suitable kinetic model for the hexavalent chromium removal in a batch reactor. The experimental data were analyzed using four adsorption kinetic models: the pseudo- first and second order equations, the Elovich equation, and the intraparticle diffusion equation, so as to determine the best fit equation of the Cr(VI) adsorption ont...
Autori: Ankica Radjenovic
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27773

Transesterification is one of the main biodiesel production method that produces huge amount of wastewater due to the high organic substance content (COD =300000-400000 mg/L, oil and grease= 17000-25000 mg/L). Although there are several treatment methods, flotation is the current conventional treatment method for oil and grease (O&G) before the biological treatment. In this study solvent extraction method was developed for pre-refining of biodiesel wastewaters. For the solvent extraction met...
Autori: Pınar Tanattı
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27850

The macrophyte Pistia stratiote was used as biosorbent for the removal of Black Krom KJR (BK-KJR) dye in synthetic aqueous solution. Initially, some tests were performed to verify the best operational conditions such as pH, biosorbent particle size, sorption temperature and stirring speed, which were later used in the kinetic and equilibrium tests. All tests were performed in duplicate. The highest removal rates of the pollutant were achieved at the process conditions of initial pH 2, granulo...
Autori: Aparecido Nivaldo Módenes
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27843

The native and surface modified adsorbents from agricultural waste, such as Psyllium stalks (PS) were investigated for their ability to remove the Coomassie Brilliant Blue (CBB) dye from aqueous media. The native and surface modified adsorbents were characterized by the Fourier Transform Infrared spectroscopy (FTIR). The results show that the Sodium Bicarbonate Treated Carbon (SBTC) has good surface properties for the removal of the CBB dye from aqueous media. The SBTC was analyzed by Scanni...
Autori: Premkumar Manickam Periyaraman
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27898