1. The document discusses batch adsorption tests conducted to establish adsorption isotherms for heavy metals like copper, chromium, lead, and cadmium onto sand in slow sand filters.
2. The tests aimed to confirm that adsorption was one of the mechanisms for heavy metal removal in slow sand filters. Results showed the adsorption followed both the Langmuir and Freundlich adsorption isotherm models.
3. Maximum adsorption capacities from the Langmuir isotherm were highest for lead, followed by copper, chromium, and cadmium. The Freundlich constant was highest for copper, possibly due to its higher initial concentration. Values exceeded 1, indicating good adsorption of
Explain Langmuir isotherm model and derive its equationZakir Ullah
The document discusses soil chemistry concepts including:
1) Classification of silicate minerals into 1:1 and 2:1 clays based on their structure.
2) Isomorphic substitution in silicate minerals where ions of similar size but different charge replace one another.
3) Calculation of permanent charge in a trioctahedral 2:1 silicate mineral based on isomorphic substitution.
Adsorption process for voc (volatile organic compounds copySaiful Islam
The document discusses the adsorption process for removing volatile organic compounds (VOCs) from air or gas streams. It defines adsorption and describes how VOCs accumulate on the surface of adsorbent materials like activated carbon. Fixed bed adsorption is commonly used, where the VOCs are removed as the contaminated air passes through a column packed with adsorbent. Key factors that influence the adsorption process include temperature, gas concentration, bed length, and regeneration of the adsorbent material. Common adsorbents for VOC removal include activated carbon beads and fibers, which can be used in continuous adsorption/desorption systems.
This document discusses adsorption, which refers to the accumulation of solutes at solid-solution interfaces in soils. There are two main types of adsorption - physical and chemical. Adsorption is determined through batch or column experiments by measuring the removal of solutes from solution onto an adsorbent. The relationship between the solute adsorbed and its equilibrium concentration is described by adsorption isotherms, with common models including linear, Freundlich, Langmuir, and BET isotherms. Adsorption of ions onto soil surfaces can occur through mechanisms such as electrostatic exchange or covalent bonding, and depends on properties of both the ion and soil surface.
Removal of cadmium from aqueous solution using cobalt silicate precipitation ...IJSIT Editor
This document discusses the removal of cadmium from aqueous solutions using cobalt silicate precipitation tubes (CoSPT) as an adsorbent. CoSPT was synthesized through a "silica garden" process and found to be an effective adsorbent for cadmium. Batch adsorption studies were conducted to determine the effect of contact time, adsorbent dose, initial cadmium concentration, temperature, and pH. Experimental data fit the Langmuir and Freundlich isotherm models well. Kinetic studies showed that the pseudo-second order model provided the best fit. The maximum adsorption capacity of CoSPT for cadmium was estimated to be 319 mg/g based on
The document discusses adsorption equilibria and regeneration. It defines adsorption as the accumulation of matter at the interface between two phases, such as a gas and a solid surface. The document then describes different types of adsorption including physical adsorption, chemical adsorption, and ion exchange. Common adsorption isotherm models are also summarized, such as the Langmuir, Freundlich, BET, and Temkin isotherms. Finally, five types of physisorption isotherms are described that can occur on solid surfaces depending on the material properties.
Adsorption is the process where matter accumulates at the interface between two phases, such as a gas transferring to the surface of a liquid. This occurs due to higher surface energy at interfaces compared to interior molecules. Adsorption equilibria can be modeled using isotherms such as Langmuir, Freundlich, and BET, which relate the amount adsorbed to concentration in solution. Factors like adsorbate properties, pH, temperature, and presence of other solutes influence adsorption extent and isotherm shape.
This document outlines Dr. Priy Brat Dwivedi's discussion on validation, kinetic modeling, and thermodynamics of adsorption process experiments. It discusses key topics like adsorption applications, adsorption vs absorption, adsorption isotherms, thermodynamics, and kinetics. Examples are provided on modeling adsorption isotherms using the Langmuir and Freundlich models. The importance of calculating thermodynamic parameters like Gibbs free energy, enthalpy, and entropy is highlighted. First-order and second-order kinetic models are introduced to study adsorption kinetics.
The document discusses surface chemistry and adsorption. It defines adsorption as molecules of a substance accumulating on the surface of a solid or liquid. Adsorption occurs due to unbalanced surface forces and is exemplified by ammonia adsorbing onto charcoal. Adsorption can be physical or chemical depending on the strength of attraction. Factors like temperature, surface area, and gas/solid properties affect adsorption extent. Adsorption finds applications in areas like vacuum production, gas masks, desiccation, catalysis and water softening.
Explain Langmuir isotherm model and derive its equationZakir Ullah
The document discusses soil chemistry concepts including:
1) Classification of silicate minerals into 1:1 and 2:1 clays based on their structure.
2) Isomorphic substitution in silicate minerals where ions of similar size but different charge replace one another.
3) Calculation of permanent charge in a trioctahedral 2:1 silicate mineral based on isomorphic substitution.
Adsorption process for voc (volatile organic compounds copySaiful Islam
The document discusses the adsorption process for removing volatile organic compounds (VOCs) from air or gas streams. It defines adsorption and describes how VOCs accumulate on the surface of adsorbent materials like activated carbon. Fixed bed adsorption is commonly used, where the VOCs are removed as the contaminated air passes through a column packed with adsorbent. Key factors that influence the adsorption process include temperature, gas concentration, bed length, and regeneration of the adsorbent material. Common adsorbents for VOC removal include activated carbon beads and fibers, which can be used in continuous adsorption/desorption systems.
This document discusses adsorption, which refers to the accumulation of solutes at solid-solution interfaces in soils. There are two main types of adsorption - physical and chemical. Adsorption is determined through batch or column experiments by measuring the removal of solutes from solution onto an adsorbent. The relationship between the solute adsorbed and its equilibrium concentration is described by adsorption isotherms, with common models including linear, Freundlich, Langmuir, and BET isotherms. Adsorption of ions onto soil surfaces can occur through mechanisms such as electrostatic exchange or covalent bonding, and depends on properties of both the ion and soil surface.
Removal of cadmium from aqueous solution using cobalt silicate precipitation ...IJSIT Editor
This document discusses the removal of cadmium from aqueous solutions using cobalt silicate precipitation tubes (CoSPT) as an adsorbent. CoSPT was synthesized through a "silica garden" process and found to be an effective adsorbent for cadmium. Batch adsorption studies were conducted to determine the effect of contact time, adsorbent dose, initial cadmium concentration, temperature, and pH. Experimental data fit the Langmuir and Freundlich isotherm models well. Kinetic studies showed that the pseudo-second order model provided the best fit. The maximum adsorption capacity of CoSPT for cadmium was estimated to be 319 mg/g based on
The document discusses adsorption equilibria and regeneration. It defines adsorption as the accumulation of matter at the interface between two phases, such as a gas and a solid surface. The document then describes different types of adsorption including physical adsorption, chemical adsorption, and ion exchange. Common adsorption isotherm models are also summarized, such as the Langmuir, Freundlich, BET, and Temkin isotherms. Finally, five types of physisorption isotherms are described that can occur on solid surfaces depending on the material properties.
Adsorption is the process where matter accumulates at the interface between two phases, such as a gas transferring to the surface of a liquid. This occurs due to higher surface energy at interfaces compared to interior molecules. Adsorption equilibria can be modeled using isotherms such as Langmuir, Freundlich, and BET, which relate the amount adsorbed to concentration in solution. Factors like adsorbate properties, pH, temperature, and presence of other solutes influence adsorption extent and isotherm shape.
This document outlines Dr. Priy Brat Dwivedi's discussion on validation, kinetic modeling, and thermodynamics of adsorption process experiments. It discusses key topics like adsorption applications, adsorption vs absorption, adsorption isotherms, thermodynamics, and kinetics. Examples are provided on modeling adsorption isotherms using the Langmuir and Freundlich models. The importance of calculating thermodynamic parameters like Gibbs free energy, enthalpy, and entropy is highlighted. First-order and second-order kinetic models are introduced to study adsorption kinetics.
The document discusses surface chemistry and adsorption. It defines adsorption as molecules of a substance accumulating on the surface of a solid or liquid. Adsorption occurs due to unbalanced surface forces and is exemplified by ammonia adsorbing onto charcoal. Adsorption can be physical or chemical depending on the strength of attraction. Factors like temperature, surface area, and gas/solid properties affect adsorption extent. Adsorption finds applications in areas like vacuum production, gas masks, desiccation, catalysis and water softening.
This document discusses various adsorption isotherms and equations used to describe adsorption processes in soils. It introduces common adsorption isotherms like Freundlich, Langmuir, BET, and Gibbs isotherms. The Freundlich equation describes adsorption in dilute solutions. The Langmuir equation assumes monolayer adsorption onto specific sites. The BET equation extends Langmuir to model multilayer adsorption. Finally, the Gibbs equation relates adsorption to changes in surface tension at liquid-gas interfaces.
Adsorption is a reversible process which is shown by solids like activated charcoal, zeolite, silica clay, alumina etc.The solute present in the feed continuously interacts with the absorbent and gets adsorbed
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
1. Adsorption is the accumulation of atoms, molecules, or ions on the surface of an adsorbent material. It is a surface phenomenon where adsorbate adheres to the surface of an adsorbent.
2. Factors that affect adsorption include the nature and surface area of the adsorbent, pressure and temperature of the adsorbate gas, and the affinity between adsorbate and adsorbent.
3. Two main types of adsorption are physical adsorption (physisorption) and chemical adsorption (chemisorption), which differ in their strength of interaction and reversibility.
The document discusses adsorption as a treatment method for removing pollutants like dyes and heavy metals from industrial effluents. It covers topics like the chemistry of adsorption, adsorption isotherms, factors affecting adsorption like pH and temperature. It also discusses the use of agricultural waste materials as low-cost adsorbents for wastewater treatment and their characterization. Activating the agricultural wastes through chemical or physical treatment can enhance their adsorption capacity. Analytical techniques are used to study the surface properties of adsorbents and how they influence adsorption.
1. Adsorption isotherms describe the amount of adsorbate on an adsorbent as a function of pressure or concentration at constant temperature. The Freundlich and Langmuir models were early mathematical fits to isotherm data.
2. The Langmuir model assumes single-layer adsorption on equivalent sites, while the BET model accounts for multilayer adsorption. The Kisliuk model considers interactions between adsorbed molecules that increase the probability of additional adsorption.
3. The Henderson-Kisliuk model describes self-assembled monolayer adsorption, where molecules first form a "lying down" structure then transition to a "standing up" orientation
- Adsorption occurs when a gas or liquid accumulates on the surface of a solid, forming a film. It differs from absorption which involves diffusion into the bulk.
- The Langmuir adsorption model describes monolayer adsorption on uniform sites but makes assumptions that do not always apply. The BET model extends it to account for multilayer adsorption.
- The Temkin isotherm accounts for indirect interactions between adsorbed molecules which affect heat of adsorption and coverage at high pressures.
The document discusses surface chemistry and catalysis. It defines key terms like adsorption, absorption, interface and provides differences between adsorption and absorption. It describes different types of adsorption like physical and chemical adsorption. Factors affecting adsorption like nature of adsorbent and adsorbate, surface area, temperature, pressure are explained. Different models of adsorption isotherms including Freundlich and Langmuir isotherms are introduced.
This document discusses different types of adsorption including physical, chemical, and exchange adsorption. It provides details on physical adsorption such as the forces involved and its exothermic and reversible nature. Chemical adsorption forms strong bonds and is usually irreversible. Exchange adsorption involves charged sites on the adsorbent surface. Common adsorbents like activated carbon, silica gel, and zeolites are also described. Adsorption isotherms models including Langmuir and Freundlich are summarized which relate the amount of adsorbate removed to its concentration at equilibrium.
The document discusses different adsorption isotherm models including Freundlich, Langmuir, and BET isotherms. The Freundlich isotherm accounts for heterogeneous adsorption sites while the Langmuir isotherm assumes monolayer adsorption. The BET isotherm built upon Langmuir's assumptions to account for multilayer adsorption. Key factors in adsorption include pressure, temperature, surface energy, and the equilibrium between adsorbed and gaseous molecules. Adsorption amounts level off at high pressures when all adsorption sites are filled.
1. Surface chemistry is the study of processes that occur at the interface between two bulk phases, such as liquid-liquid, liquid-solid, or gas-solid.
2. There are two main types of interactions between substances and surfaces: adsorption, where molecules adhere to the surface, and absorption, where molecules enter and spread within the surface or bulk material.
3. Adsorption can be physical (weak van der Waals forces) or chemical (stronger chemical bonding), and adsorption equilibria determine how much of a substance will adsorb based on conditions like pressure, temperature, and surface area.
This document discusses the topics of adsorption, catalysis, and surface chemistry. It defines key terms like adsorption, adsorbent, adsorbate, and describes factors that affect adsorption like temperature, pressure, and surface area. It distinguishes between physisorption and chemisorption. It also defines and provides examples of different types of catalysis like homogeneous and heterogeneous catalysis. Theories of catalysis discussed include intermediate compound formation theory and adsorption theory. Applications of adsorption and catalysis are also mentioned, including catalytic converters.
This document discusses Langmuir adsorption isotherm, which explains monolayer adsorption of gases onto surfaces. It assumes adsorption occurs at specific identical sites, with no lateral interactions between adsorbed molecules. Langmuir derived an equation showing the relationship between fraction of surface coverage (θ) and gas pressure (P), based on equilibrium between adsorption and desorption rates. This model applies at low pressures and assumes only monolayer coverage, with limitations at high pressures where multilayers can form. The document also outlines assumptions, derivation of the Langmuir equation, and applications for measuring moisture adsorption.
The students measured the surface area of charcoal using the adsorption of acetic acid. They titrated solutions with varying concentrations of acetic acid exposed to charcoal to determine the equilibrium concentration and moles of acid adsorbed per gram of charcoal. Plotting these values showed they were directly proportional, allowing the students to determine the monolayer capacity from the slope. Using this monolayer capacity, the students calculated the surface area of the charcoal to be 657.35±20.22 m2/g, which was within 48% of the literature value. The adsorption was found to follow the Langmuir isotherm model of adsorption on a homogeneous surface.
The document discusses adsorption, which is the process by which a substance accumulates at the interface between a solid and liquid or gas phase. It defines key terms like adsorbate, adsorbent, and driving force. The document notes that activated carbon is commonly used as an adsorbent in wastewater treatment due to its high surface area. Factors affecting adsorption include surface area, particle size, contact time, and affinity between solute and adsorbent. Adsorption follows either a Langmuir, BET, or Freundlich isotherm model depending on the system. The Langmuir model assumes monolayer adsorption onto specific sites and can be derived using rate equations
Type of adsorption- Pharmaeutical Physical ChemistrySanchit Dhankhar
Adsorption
Adsorption versus absorption, Desorption
Types of adsorption: Physisorption and Chemisorption
Factors affecting adsorption
Adsorption isotherms: Freundlich and Langmuir
Gibbs adsorption isotherm
Bet equation and its use in surface area determination
Applications
ADSORPTION
Adsorption is the process in which matter is extracted from one phase and concentrated at the surface of a second phase. (Interface accumulation). This is a surface phenomenon as opposed to absorption where matter changes solution phase, e.g. gas transfer. This is demonstrated in the following schematic.
A Method For Evaluating the Sorption Capacity of The SorbentsIJMERJOURNAL
ABSTRACT: A new method for evaluating the sorption capacity of the sorbents is offered. The proposed model is based on the adsorption data of the sorbent depending on the sorption duration in static mode. The new model allows to quickly and easily evaluate the duration of sorbent saturation. The formula of this relationship is determined by means of plotting of sorbent saturation curve on the base of experimental data, and using of Exel Trendline program. After the appropriate calculations and plotting q from time the sorption capacity of the sorbent is estimated. The model, as a primary parameter, includes time. The experimental data were obtained on the base of peat-containing sorbent for sorption of copper and cobalt. Sorption processes were evaluated by ICP-MS.
The document discusses various topics related to states of matter and adsorption isotherms. It begins by explaining the particulate theory of matter proposed by Democritus and developed by Dalton. It then describes the three traditional states of matter - solid, liquid, and gas - and how their properties, such as density, differ. A fourth state of matter, plasma, is also introduced. The document then discusses adsorption isotherms and models such as Langmuir and Freundlich isotherms that describe the relationship between gas or liquid concentration and adsorption. Examples are provided to illustrate applying these isotherm models.
This document discusses various adsorption isotherms and equations used to describe adsorption processes in soils. It introduces common adsorption isotherms like Freundlich, Langmuir, BET, and Gibbs isotherms. The Freundlich equation describes adsorption in dilute solutions. The Langmuir equation assumes monolayer adsorption onto specific sites. The BET equation extends Langmuir to model multilayer adsorption. Finally, the Gibbs equation relates adsorption to changes in surface tension at liquid-gas interfaces.
Adsorption is a reversible process which is shown by solids like activated charcoal, zeolite, silica clay, alumina etc.The solute present in the feed continuously interacts with the absorbent and gets adsorbed
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
1. Adsorption is the accumulation of atoms, molecules, or ions on the surface of an adsorbent material. It is a surface phenomenon where adsorbate adheres to the surface of an adsorbent.
2. Factors that affect adsorption include the nature and surface area of the adsorbent, pressure and temperature of the adsorbate gas, and the affinity between adsorbate and adsorbent.
3. Two main types of adsorption are physical adsorption (physisorption) and chemical adsorption (chemisorption), which differ in their strength of interaction and reversibility.
The document discusses adsorption as a treatment method for removing pollutants like dyes and heavy metals from industrial effluents. It covers topics like the chemistry of adsorption, adsorption isotherms, factors affecting adsorption like pH and temperature. It also discusses the use of agricultural waste materials as low-cost adsorbents for wastewater treatment and their characterization. Activating the agricultural wastes through chemical or physical treatment can enhance their adsorption capacity. Analytical techniques are used to study the surface properties of adsorbents and how they influence adsorption.
1. Adsorption isotherms describe the amount of adsorbate on an adsorbent as a function of pressure or concentration at constant temperature. The Freundlich and Langmuir models were early mathematical fits to isotherm data.
2. The Langmuir model assumes single-layer adsorption on equivalent sites, while the BET model accounts for multilayer adsorption. The Kisliuk model considers interactions between adsorbed molecules that increase the probability of additional adsorption.
3. The Henderson-Kisliuk model describes self-assembled monolayer adsorption, where molecules first form a "lying down" structure then transition to a "standing up" orientation
- Adsorption occurs when a gas or liquid accumulates on the surface of a solid, forming a film. It differs from absorption which involves diffusion into the bulk.
- The Langmuir adsorption model describes monolayer adsorption on uniform sites but makes assumptions that do not always apply. The BET model extends it to account for multilayer adsorption.
- The Temkin isotherm accounts for indirect interactions between adsorbed molecules which affect heat of adsorption and coverage at high pressures.
The document discusses surface chemistry and catalysis. It defines key terms like adsorption, absorption, interface and provides differences between adsorption and absorption. It describes different types of adsorption like physical and chemical adsorption. Factors affecting adsorption like nature of adsorbent and adsorbate, surface area, temperature, pressure are explained. Different models of adsorption isotherms including Freundlich and Langmuir isotherms are introduced.
This document discusses different types of adsorption including physical, chemical, and exchange adsorption. It provides details on physical adsorption such as the forces involved and its exothermic and reversible nature. Chemical adsorption forms strong bonds and is usually irreversible. Exchange adsorption involves charged sites on the adsorbent surface. Common adsorbents like activated carbon, silica gel, and zeolites are also described. Adsorption isotherms models including Langmuir and Freundlich are summarized which relate the amount of adsorbate removed to its concentration at equilibrium.
The document discusses different adsorption isotherm models including Freundlich, Langmuir, and BET isotherms. The Freundlich isotherm accounts for heterogeneous adsorption sites while the Langmuir isotherm assumes monolayer adsorption. The BET isotherm built upon Langmuir's assumptions to account for multilayer adsorption. Key factors in adsorption include pressure, temperature, surface energy, and the equilibrium between adsorbed and gaseous molecules. Adsorption amounts level off at high pressures when all adsorption sites are filled.
1. Surface chemistry is the study of processes that occur at the interface between two bulk phases, such as liquid-liquid, liquid-solid, or gas-solid.
2. There are two main types of interactions between substances and surfaces: adsorption, where molecules adhere to the surface, and absorption, where molecules enter and spread within the surface or bulk material.
3. Adsorption can be physical (weak van der Waals forces) or chemical (stronger chemical bonding), and adsorption equilibria determine how much of a substance will adsorb based on conditions like pressure, temperature, and surface area.
This document discusses the topics of adsorption, catalysis, and surface chemistry. It defines key terms like adsorption, adsorbent, adsorbate, and describes factors that affect adsorption like temperature, pressure, and surface area. It distinguishes between physisorption and chemisorption. It also defines and provides examples of different types of catalysis like homogeneous and heterogeneous catalysis. Theories of catalysis discussed include intermediate compound formation theory and adsorption theory. Applications of adsorption and catalysis are also mentioned, including catalytic converters.
This document discusses Langmuir adsorption isotherm, which explains monolayer adsorption of gases onto surfaces. It assumes adsorption occurs at specific identical sites, with no lateral interactions between adsorbed molecules. Langmuir derived an equation showing the relationship between fraction of surface coverage (θ) and gas pressure (P), based on equilibrium between adsorption and desorption rates. This model applies at low pressures and assumes only monolayer coverage, with limitations at high pressures where multilayers can form. The document also outlines assumptions, derivation of the Langmuir equation, and applications for measuring moisture adsorption.
The students measured the surface area of charcoal using the adsorption of acetic acid. They titrated solutions with varying concentrations of acetic acid exposed to charcoal to determine the equilibrium concentration and moles of acid adsorbed per gram of charcoal. Plotting these values showed they were directly proportional, allowing the students to determine the monolayer capacity from the slope. Using this monolayer capacity, the students calculated the surface area of the charcoal to be 657.35±20.22 m2/g, which was within 48% of the literature value. The adsorption was found to follow the Langmuir isotherm model of adsorption on a homogeneous surface.
The document discusses adsorption, which is the process by which a substance accumulates at the interface between a solid and liquid or gas phase. It defines key terms like adsorbate, adsorbent, and driving force. The document notes that activated carbon is commonly used as an adsorbent in wastewater treatment due to its high surface area. Factors affecting adsorption include surface area, particle size, contact time, and affinity between solute and adsorbent. Adsorption follows either a Langmuir, BET, or Freundlich isotherm model depending on the system. The Langmuir model assumes monolayer adsorption onto specific sites and can be derived using rate equations
Type of adsorption- Pharmaeutical Physical ChemistrySanchit Dhankhar
Adsorption
Adsorption versus absorption, Desorption
Types of adsorption: Physisorption and Chemisorption
Factors affecting adsorption
Adsorption isotherms: Freundlich and Langmuir
Gibbs adsorption isotherm
Bet equation and its use in surface area determination
Applications
ADSORPTION
Adsorption is the process in which matter is extracted from one phase and concentrated at the surface of a second phase. (Interface accumulation). This is a surface phenomenon as opposed to absorption where matter changes solution phase, e.g. gas transfer. This is demonstrated in the following schematic.
A Method For Evaluating the Sorption Capacity of The SorbentsIJMERJOURNAL
ABSTRACT: A new method for evaluating the sorption capacity of the sorbents is offered. The proposed model is based on the adsorption data of the sorbent depending on the sorption duration in static mode. The new model allows to quickly and easily evaluate the duration of sorbent saturation. The formula of this relationship is determined by means of plotting of sorbent saturation curve on the base of experimental data, and using of Exel Trendline program. After the appropriate calculations and plotting q from time the sorption capacity of the sorbent is estimated. The model, as a primary parameter, includes time. The experimental data were obtained on the base of peat-containing sorbent for sorption of copper and cobalt. Sorption processes were evaluated by ICP-MS.
The document discusses various topics related to states of matter and adsorption isotherms. It begins by explaining the particulate theory of matter proposed by Democritus and developed by Dalton. It then describes the three traditional states of matter - solid, liquid, and gas - and how their properties, such as density, differ. A fourth state of matter, plasma, is also introduced. The document then discusses adsorption isotherms and models such as Langmuir and Freundlich isotherms that describe the relationship between gas or liquid concentration and adsorption. Examples are provided to illustrate applying these isotherm models.
Pakistan; Removal of heavy metals from Water Through Adsorption Using SandV9X
This article examines the removal of heavy metals (Pb, Cr, Cu, Zn) from aqueous solutions using ordinary sand as an adsorbent. Batch experiments were conducted by adding sand to metal salt solutions and measuring metal concentration after 24 hours. The data fit the Langmuir adsorption isotherm model well. The maximum amount of metal adsorbed to form a monolayer (am) was highest for Pb and lowest for Zn, indicating Pb's stronger interaction with sand. This preference is attributed to the metals' relative abilities to hydrolyze, with more easily hydrolyzed ions (like Pb2+) favoring chemisorption to silicate surface sites. The study concludes that while sand
Equilibrium and kinetic study on chromium (vi) removal from simulatedGJESM Publication
Gooseberry seed powder was investigated as a novel biosorbent for the removal of chromium (VI) from simulated wastewater. Batch experiments were conducted to determine the effects of parameters such as pH, contact time, initial metal concentration, and adsorbent dosage on chromium removal efficiency. Maximum removal of 96% was achieved under optimal conditions at pH 2 within 60 minutes of contact time. Adsorption isotherm and kinetic models were applied to understand the adsorption mechanism, with the data fitting well to the Langmuir isotherm model and pseudo-second order kinetic model. The results indicate that gooseberry seed powder has potential as an effective and economical adsorbent for chromium removal.
Titanium Cerium Ferrite ( Tcf ) Was Prepared By A Simple...Dana Boo
The document discusses the characterization of three mesoporous materials: SBA-15, thiol-functionalized SBA-15, and bismuth-functionalized SBA-15. Nitrogen adsorption/desorption isotherms show that all three samples have type IV isotherms, indicating mesoporous structures with pore sizes larger than 5.6 nm. The pore diameter decreases with each functionalization step due to molecules attaching within the pores. BET surface area and pore volume also decrease with each functionalization as groups occupy the internal pore space. The design of a uniform mesoporous structure is favorable for functionalization and applications.
1) The document summarizes a study that assessed the effectiveness of using bottom ash as an adsorbent for removing lead (Pb) from wastewater. Physical, chemical, and mineralogical characterization of bottom ash was performed, along with tests to determine its Pb adsorption capacity and kinetics.
2) Kinetic data showed that Pb adsorption by bottom ash fit the pseudo-second order model best. Adsorption isotherm analysis indicated that the Freundlich isotherm model governed the equilibrium process.
3) The study concluded that bottom ash is an effective and low-cost adsorbent for removing Pb from wastewater, with its adsorption capacity increasing
Adsorption, concentration, and recovery of aqueous heavy metal ions with the ...Fabian Andres Granobles
The document investigates the adsorption of copper and chromium ions from wastewater using the root powder of Eichhornia crassipes. The maximum adsorption capacities were 32.51 mg/g for copper and 33.98 mg/g for chromium under optimal pH conditions of 5-6. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy showed that functional groups containing OH and COOH contributed to adsorption through complex formation. During adsorption, calcium, magnesium, and potassium ions were discharged from the root powder, indicating an ion exchange mechanism. Combusting the saturated adsorbent generated products with high concentrations of metal ions, providing an effective way to concentrate and recover the metals from wastewater.
This document provides information about adsorption, including definitions, examples, and applications. It defines adsorption as the accumulation of molecules on a surface, with the adsorbent being the surface and the adsorbate being the accumulated substance. There are two main types of adsorption: physical adsorption via van der Waals forces, and chemical adsorption via chemical bonds. Factors that affect adsorption include properties of the adsorbate and adsorbent, as well as surface area, pressure, and temperature. Common applications of adsorption include decolorization, gas masks, vacuum systems, catalysis, indicators, chromatography, and moisture control.
Adsorption is the process where gas, liquid, or dissolved molecules accumulate on the surface of a solid or liquid. It is different from absorption, where the substance diffuses into another. Adsorption occurs in natural and industrial systems due to surface energy, and can be described through isotherms relating amount adsorbed to pressure or concentration. Common adsorbents used are activated carbon, silica gel, zeolites, and their characteristics, such as surface area, determine their applications such as purification.
Removal of Heavy Metals from Aqueous Solutions by Modified Activated Carbon f...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
11.biosorption of heavy metals from aqueous solutions using water hyacinth as...Alexander Decker
This document summarizes a study that investigated using water hyacinth fiber as a low-cost biosorbent for removing copper and zinc ions from aqueous solutions. The study examined the effect of initial solution concentration, initial biomass concentration, and temperature on biosorption. Equilibrium adsorption data fit well with four isotherm models (Langmuir, Freundlich, Temkin, Dubinin-Radushkevich). Results showed that water hyacinth has a high affinity and sorption capacity for copper and zinc ions, with maximum capacities of 99.42 mg Cu2+ and 83.01 mg Zn2+ per 1 g of biomass. The study demonstrated that water hyacinth fiber is an
kapasitas adsorpsi tanah napa terhadap ion krom (III)Syukrya Ningsih
This document summarizes a study that determined the maximum adsorption capacity of Napa soil for chromium ions (Cr3+). The study investigated various parameters that affect adsorption capacity including pH, initial chromium concentration, particle size, temperature of heating the adsorbent, solution flow rate. The results showed that optimum adsorption of chromium ions occurred at pH 5, initial concentration of 250 mg/L, particle size of 850 μm, temperature of heating the adsorbent at 125°C, and flow rate of 20 drops/min. Under these conditions, the maximum adsorption capacity of Napa soil for chromium ions was determined to be 3.28 mg/g.
The document summarizes research on the adsorption of copper(II) and nickel(II) ions onto a polymeric resin called PMBMNen. Key findings include:
1) The resin showed maximum adsorption (88-90%) of copper and (86-88%) of nickel at pH 6, reaching equilibrium within 60 minutes.
2) Adsorption increased with concentration but decreased with increasing flow rate and volume of metal solutions.
3) Adsorption data fit the Freundlich isotherm model best, and thermodynamic parameters (negative ΔH, ΔS, ΔG) indicated spontaneity and exothermic adsorption.
4) The resin effectively removed
Adsorption, types of adsorption, physisorption, chemisorption, mechanism of adsorption, Difference between adsorption and absorption, Factors affecting adsorption, applications of adsorption-
Gas masks
Adsorption indicators
Chromatographic separation
Removal of coloring matter
Heterogeneous catalysis
Controlling humidity
Curing diseases
Froth flotation process
Production of high vacuum
Purification,
adsorption equilibrium, adsorption isotherms, Langmuir isotherm- assumptions, Langmuir equation, limitations of Langmuir isotherm, equation, Freundlich isotherm- Assumptions of Freundlich Isotherm,Limitations of Freundlich Isotherm,Differences between Freundlich and Langmuir adsorption isotherms, BET isotherm-Drawbacks of BET adsorption theory, Types of BET adsorption isotherms, Differences between Langmuir and BET adsorption isotherm, Applications of BET isotherm, Why is Langmuir surface area always higher than BET surface area?
Temkin isotherm, D-R isotherms, Drawbacks of D-R Isotherm, Drawbacks of Temkin Isotherm, Uses of D-R isotherms, applications of adsorption isotherms -Spontaneity,
Exothermicity,
Percentage removal of adsorbate,
Langmuir parameters- maximum adsorbent uptake and affinity between adsorbent and adsorbate,Freundlich parameters- adsorption capacity of adsobents.
BET isotherms- specific surface area, pore size distribution curves
D-R parameters- adsorption mechanism
Temkin parameters- adsorbent-adsobate interactions
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Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. There are two types: physical adsorption (physisorption) which involves weak van der Waals forces, and chemical adsorption (chemisorption) which involves covalent bonding. Adsorption is described by isotherm models like the Freundlich and Langmuir isotherms, which relate the amount of adsorbate to its pressure or concentration at equilibrium. Activated carbon is commonly used as an adsorbent due to its high surface area and pore volume. Adsorption has applications in gas masks, water treatment, chromatography and catalysis.
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Adsorbents are solids or liquids that can attract and hold other molecules or atoms onto their surfaces through weak intermolecular forces. Adsorption is used in chromatography to separate mixtures and is dependent on factors like the properties of the adsorbent and adsorbate. Common adsorbents used include activated alumina and charcoal due to their large surface area, mechanical stability, and ability to adsorb a wide variety of compounds without reacting. Adsorption has several applications including air and water purification, humidity control, and separation techniques like adsorption chromatography and ion exchange.
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Pakistan; Adsorption of Heavy Metals In Slow Sand Filters Systems
1. T WATER TREATMENT: MUHAMMAD, PARR, SMITH and WHEATLEY
24th WEDC Conference Islamabad, Pakistan, 1998
SANITATION AND WATER FOR ALL
Adsorption of heavy metals in slow sand filters
Nur Muhammad, Jeremy Parr, Michael D. Smith and Andrew D. Wheatley, WEDC
CHEMICAL CONTAMINANTS AT low concentrations are dif- adsorption isotherm is often used for adsorption of a solute
ficult to remove from water. Chemical precipitation, re- from a liquid solution. The Langmuir adsorption isotherm
verse osmosis and other methods become inefficient when is perhaps the best known of all isotherms describing
contaminants are present in trace concentrations. The adsorption and is often expressed as:
process of adsorption is one of the few alternatives avail-
Qe= XmKCe/(1+KCe) (Casey, 1997)
able for such situations (Huang and Morehart, 1991). A
number of adsorbent materials have been studied for their where:
capacity to remove heavy metals, including activated car-
Qe is the adsorption density at the equilibrium solute
bon, activated alumina, ion exchange resins, crushed coals
concentration Ce (mg of adsorbate per g of adsorbent)
etc. Some of these materials, such as ion exchange resins are
Ce is the concentration of adsorbate in solution (mg/l)
totally effective but expensive and others, such as coal and
Xm is the maximum adsorption capacity corresponding to
straw, are inexpensive but ineffective. Activated carbon is
complete monolayer coverage (mg of solute adsorbed per g
very effective in removing heavy metals, but is readily
of adsorbent)
soluble under extreme pH conditions (Huang and
K is the Langmuir constant related to energy of adsorption(l
Blankenship, 1989). Peat moss has been found as very
of adsorbent per mg of adsorbate)
effective in adsorbing heavy metals (Ho, 1995). In the
The above equation can be rearranged to the following
present study Slow Sand Filters (SSFs) are tried to remove
linear form:
heavy metals and found very effective (Muhammad et al,
1997). Experimental results on the influences of process Ce/Qe = 1/XmK + Ce/Xm
variables in removing heavy metals by SSFs demonstrated
The linear form can be used for linearisation of experi-
that adsorption was one of the mechanisms of the removal
mental data by plotting Ce/Qe against Ce. The Langmuir
of heavy metals (Muhammad et al, 1997). To confirm this
constants Xm and K can be evaluated from the slope and
prediction/hypothesis, batch adsorption tests were carried
intercept of linear equation.
out. This paper deals with the results of the batch adsorp-
tion tests to establish adsorption isotherms and adsorption
capacity of the sand for the selected heavy metals. Freundlich isotherm
Herbert Max Finley Freundlich, a German physical chem-
ist, presented an empirical adsorption isotherm for non-
Adsorption Isotherms ideal systems in 1906. The Freundlich isotherm is the
Two important physiochemical aspects for the evaluation earliest known relationship describing the adsorption equa-
of the adsorption process as a unit operation are the tion and is often expressed as:
equilibria of the adsorption and the kinetics. Equilibrium
studies give the capacity of the adsorbent (Ho, 1995). The Qe= KfCe1/n (Casey, 1997)
equilibrium relationships between adsorbent and adsorb- where:
ate are described by adsorption isotherms, usually the ratio
between the quantity adsorbed and that remaining in Qe is the adsorption density (mg of adsorbate per g of
solution at a fixed temperature at equilibrium. There are adsorbent)
two types of adsorption isotherms : Langmuir adsorption Ce is the concentration of adsorbate in solution (mg/l)
isotherms and Freundlich adsorption isotherms. Kf and n are the empirical constants dependent on several
environmental factors and n is greater than one.
This equation is conveniently used in the linear form by
Langmuir isotherm
taking the logarithmic of both sides as:
Irving Langmuir, an American chemist who was awarded
the Nobel prize for chemistry in 1932 for “his discoveries lnQe = lnKf + 1/n lnCe.
and researches in the realm of surface chemistry”, devel-
oped a relationship between the amount of gas adsorbed on A plot of lnCe against lnQe yielding a straight line
surface and the pressure of that gas. Such equations are now indicates the confirmation of the Freundlich isotherm for
referred to as Langmuir adsorption isotherms, a theoretical adsorption. The constants can be determined from the
adsorption isotherms in the ideal case. The Langmuir slope and the intercept.
346
2. T WATER TREATMENT: MUHAMMAD, PARR, SMITH and WHEATLEY
Method used for Batch Adsorption Tests and Cd. Similarly the values of lnCe were plotted against
The method developed by Ho in 1995 was used for the the values of lnQe, also giving straight lines for all four
batch adsorption tests for different heavy metals. The heavy metals. The linear equations and the correlation
procedures for the tests are as follows: coefficients are summarised in Table 5. These results (and
the fact that the regression coefficients were very close to
• 1g of sand as an adsorbent was taken in 250 mls of metal one, indicating good linearity) confirm that the adsorption
solution. The concentration of the adsorbent was 4 g/l. of Cu, Cr, Pb and Cd on sand follow the two theroies of
• the conical flasks were capped and shaken in the flask adsorption - the Langmuir and the Freundlich adsorption
shaker at 200rpm for 4 hours. isotherm (respectively).
• the temperature was fixed at 20°C and pH was adjusted The Langmuir constant Xm (maximum adsorption capac-
at 7.2 to 7.5. ity) and the Freundlich constant Kf were obtained from the
• at least five different concentrations of each metal were linear equations. The values are summarised in Table 6.
considered. The maximum adsorption capacity of sand is the highest
• the sample was filtered through Whatman 540 mm for Pb followed by Cu, Cr and Cd. The Freundlich constant
filter paper and the effluent concentration determined. Kf for Cu is greater than the other heavy metals. It may be
• Qe was determined and Ce vs Ce/Qe and lnCe vs lnQe due to the higher influent concentration of Cu. The values
were plotted. of n for all four heavy metals were obtained as greater than
one which indicates good adsorption of these metals onto
Results and discussions sand.
To establish the adsorption isotherms and evaluate the
adsorption capacity of sand, individual metal was tested in
Conclusions
triplicate. The results described here are the average of three
• The results build on earlier work (Muhammad et al,
sets of tests.
1997) in showing that slow sand filters are effective in
Batch adsorption test results for Cu, Cr, Pb and Cd the removal of heavy metals. This has particular signifi-
Tables 1, 2, 3, and 4 describe summaries of the batch cance to developing countries as SSFs are probably the
adsorption test results to establish Langmuir and Freundlich most appropriate water treatment option in such cir-
isotherms. cumstances. In addition, many developing countries
The values of Ce was plotted against the values of Ce/Qe, suffer from chemical contamination of water supplies,
yielding straight line relatrionships for each of Cu, Cr, Pb largely due to uncontrolled industrial activity - and so
Table 1. Summary of the batch adsorption test results for Cu
No of obsrvations C (mg/l) Q (mg/g of sand) Ce /Q lnC lnQ
e e e e e e
1 940 145.0 6.48 6.84 4.98
2 1860 250.0 7.44 7.52 5.52
3 2750 312.5 8.80 7.92 5.74
4 3200 332.5 9.62 8.08 5.80
Table 2. Summary of the batch adsorption test results for Cr
No of obsrvations C (mg/l) Q (mg/g of sand) Ce /Q lnC lnQ
e e e e e e
1 128.0 28.9 4.43 4.85 3.36
2 268.5 55.8 4.82 5.60 4.02
3 404.6 79.9 5.06 6.00 4.38
4 560.0 108.6 5.60 6.32 4.69
347
3. T WATER TREATMENT: MUHAMMAD, PARR, SMITH and WHEATLEY
Table 3. Summary of the batch adsorption test results for Pb
No of obsrvations C (mg/l) Q (mg/g of sand) Ce /Q lnC lnQ
e e e e e e
1 68.0 15.0 4.54 4.22 2.71
2 96.0 20.5 4.70 4.56 3.02
3 260.0 54.0 4.80 5.56 3.99
4 355.0 71.5 4.96 5.87 4.27
Table 4. Summary of the batch adsorption test results for Cd
No of obsrvations C (mg/l) Q (mg/g of sand) Ce /Q lnC lnQ
e e e e e e
1 115.8 14.3 8.1 4.75 2.66
2 256.3 29.3 8.8 5.55 3.38
3 412.9 40.4 10.2 6.02 3.70
4 543.6 49.2 11.1 6.30 3.90
Table 5. Linear regression data for Langmnuir and Freuanlich isotherms
Langmuir data Freundlich data
Heavy metal linear equation correlation linear equation correlation
coefficient r2 coefficient r2
Cu y=0.0011x+5.390 0.9916 y=0.6709x+0.418 0.9867
Cr y=0.0018x+4.275 0.9439 y=0.901x-1.0163 0.9996
Pb y=0.0012x+4.5108 0.9022 y=0.9521x-1.3128 0.9999
Cd y=0.0072x+7.1472 0.9893 y=0.7937x-1.0759 0.9957
(note: for Langmuir data x=Ce and y=Ce/Qe ; for Freundlich data x=lnCe and y=lnQe)
Table 6. Comparison of the isotherm constants
Heavy metal Langmuir Constant Xm Freundlich Constant Kf
(Maximum adsorption capacity
in mg/g of sand)
Cu 719.0 1.52
Cr 556.0 0.36
Pb 833.0 0.27
Cd 139.0 0.34
348
4. T WATER TREATMENT: MUHAMMAD, PARR, SMITH and WHEATLEY
a water treatment technique which is able to deal with H O, Y.S., 1995, Adsorption of Heavy Metals from Waste
such pollutants in an effective way is very valuable. Streams by Natural Materials, PhD Thesis, The Univer-
• Adsorption of Cu, Cr, Pb and Cd onto sand satisfied the sity of Birmingham, UK.
Langmuir and Freundlich isotherms. HUANG, C.P., and BLANKENSHIP, B.W., 1989, The
• The adsorption capacity of sand was the highest for Pb Removal of Mercury(II) from Dilute Aqueous Solution
followed by Cu, Cr and Cd. by Activated Carbon, Water Research, 18, pp 37-46
• The values of Freundlich exponent n were greater than HUANG, C.P., and MOREHART, A.L., 1991, Protein
one for all four heavy metals confirming the adsorption Competition in Cu(II) Adsorption in Fungal Mycellia,
of these metals onto sand. Water Research, 25, pp 1365-1375.
• Hence the hypothesis of adsorption of heavy metals in MUHAMMAD, N., PARR, J., SMITH, M.D., and
slow sand filters as a significant mechanism of removal WHEATLEY, A.D., 1997, Removal of Heavy Metals by
is confirmed by the batch adsorption test results. Tra- Slow Sand Filtration, Proceedings of the 23rd WEDC
ditionally, much of the treatment capacity of SSFs has International Conference on Water Supply and Sanita-
been attributed to the action of the microbiological tion, Durban, South Africa, pp 167-170.
schmutzdecke layer. This research shows that the
adsorption activity of the sand bed is also significant.
NUR MUHAMMAD, WEDC.
JEREMY PARR, WEDC.
References MICHAEL D. SMITH, WEDC.
CASEY, T.J., 1997, Unit Treatment Processes in Water ANDREW D. WHEATLEY, Department of Civil
and Wastewater Engineering, John Wiley and Sons Ltd, Engineering.
England, pp113-114
349