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1. Taibah University, Faculty of Applied Science, Al-Madinah Al-Munawarah, KSA
2. Taibah University, Faculty of Science, Al-Madinah Al-Munawarah, KSA
Received: December 03, 2011 / Accepted: December 29, 2011 / Published: February 25, 2012.
Abstract: The efficiency of grounded date stone (Phoenix dactylifera L.) as biosorbent for water remediation was investigated. The sorption of Saudi Arabia date stones is supposed to take place mainly by electrostatic attraction between negatively charged stones surface and metals. The stone surface is negative because of translocation of sugars and proteins (containing N, S and P) from dates to stones. Various physicochemical parameters that influence the speciation and mobility of metal contaminants such as pH, contact time, adsorbent mass, and adsorbate initial concentration was applied. The general trend is that the metal uptake increases when the pH increases.
Key words: Date stone, extraction, heavy elements, adsorbent mass, contact time.
1. Introduction??
Ground, surface, and processing water frequently contain dissolved heavy metals that may arise from operations of mines, factories, and other industries. These metals are frequently difficult and expensive to remove. Metal-contaminated waters may include ions of copper, zinc, nickel, lead, cadmium, mercury, chromium, and uranium. All of these elements have toxicity to animals, plants, and other organisms or may deleteriously affect sensitive environments. In addition, even more innocuous materials may have low limits for discharge under certain conditions. A variety of reactions may occur which influence the speciation and mobility of metal contaminants including acid/base, precipitation/dissolution, oxidation/ reduction, sorption or ion exchange. Precipitation, sorption, and ion exchange reactions can retard the movement of metals in groundwater. The rate and extent of these reactions will depend on factors such as pH, Eh, complexation with other dissolved constituents, sorption and ion exchange capacity of the geological materials, and organic matter content. Ground-water flow characteristics also influence the transport of metal contaminants. Adsorption onto activated carbon is very effective method for metal removal but its use is limited because of high cost. Biosorption, the passive uptake of heavy metals by biomaterials, can be both highly efficient and of low cost. The date (Phoenix dactylifera L.) has been an important crop in arid and semiarid regions of the world. It has always played an important part in the economic and social lives of the people of these regions. Saudi Arabia is considered to be one of the date producing countries; the number of these trees is estimated to be over 4 million and around 100,000 tons of dates are produced annually. Biosorbent is defined as one which is abundant in nature, or is a by-product of waste material from industry or agriculture such as orange wastes [1], olive stones [2], papaya wood [3], grape stalk waste, peas,
inferred that the percent removal of metal ion increases with increasing adsorbents doses from (0.1-0.2 g) for lead and (o.1-0.8) for copper. After that there were non significant increases in removal percentages. This suggests that after a certain dose of adsorbent, the maximum adsorption is attained and hence the amount of ions bound to the adsorbent and the amount of free ions remains constant even with further addition of the dose of adsorbent. The increase in removal percentage with increase in adsorbent dose is due to the greater availability of the exchangeable sites or surface area at higher concentration of the adsorbent.
3.1.5 Potentiometric Measurements
The samples under treatment were measured by the selective sensor [9] for Cu metal ions and the results obtained were in agreement with that obtained with that of AAS.
4. Conclusions
The aim of this paper is to assess the ability of date stone to adsorb Cu(II) and Pb(II) ions from aqueous solutions. The effect of the solution pH, contact time and adsorbent dosage on the removal these ions was studied. Taking into consideration of the above results, it can be concluded that the date stone is a suitable adsorbent for the removal of Cu(II)and Pb(II) ions from aqueous solution in terms of low cost, natural and
We would like to extend our thanks and appreciation to The Deanship of Scientific Research, Taibah University, KSA for supporting this project by grant No. 431/700.
References
[1] A.B. Prez-Marin, A. Ballester, F. Gonzlez, M.L. Blzquez, J.A. Muoz, J. Sez, et al., Study of cadmium, zinc and lead biosorption by orange wastes using the subsequent addition method, Bioresource Technology 99 (17) (2008) 8101-8106.
[2] G. Blazquez, F. Herna′inz, M. Calero, L.F. Ruiz-Nunez, Removal of cadmium ions with olive stones: the effect of some parameters, Process Biochemistry 40 (2005) 2649-2654.
[3] S. Asma, A.M. Washeed, I. Muhammed, Removal and recovery of heavy metals from aqueous solution using papaya wood as a new biosorbent, Separation and Purification Technology 45 (2005) 25-31.
[4] H. Bena?ssa, Screening of new sorbent materials for cadmium removal from aqueous solutions, Hazardous Materials 132 (2006) 189-195.
[5] S. Schiewer, S.B. Patil, Pectin-rich fruit wastes as biosorbents for heavy metal removal: Equilibrium and kinetics, Bioresource Technology 99 (2008) 1896-1903.
[6] G.H. Pino, L.M.S. De Mesquita, M.L. Torem, G.A.S. Pinto, Biosorption of cadmium by green coconut shell powder, Minerals Engineering 19 (2006) 380-387.
[7] E. Augustine, H. Yuh-Shan, Effect of pH on cadmium biosorption by coconut copra mea, Hazardous Materials 139 (2007) 356-362.
[8] F. Pagnanelli, S. Mainelli, F. Veglio, L. Toro, Heavy metal removalby olive pomace: Biosorbent characterization and equilibrium modeling, Chemistry Engineering of Science 58 (2003) 4709-4717.
[9] W.H. Mahmoud, A.H. Kamel, M.S. Mostafa, Response characteristics of copper- selective polymer membrane electrodes based on a newly synthesized macrocylcic calix[4]arene derivative as a neutral carrier ionophore, Electroanalysis 22 (2010) 2453-2459
[10] S.A. Al-barrak, S.M. Elsaid, Pesticides Removal from drainage Waste water using some agriculture wastes, Pakistan Journal of biological Science 8 (3) (2005) 374-378.
[11] P. Lodeiro, J.L. Barriada, R. Herrero, M.E. Vicente, The marine macro algae Cystoseira baccata as biosorbent for cadmium(II) and lead(II) removal: kinetic and equilibrium studies, Environmental Pollution 142 (2006) 264-273.
[12] C.F. Baes, R.E. Mesmer, The hydrolysis of cations, Wiley, New York, 1976.
[13] R.M. Smith, A.E. Martell, Critical stability constants, Plenum Press, New York, 1976.
[14] B. Stephen, N. Sulochana, Carbonised jackfruit peel as an adsorbent for the removal of Cd (II) from aqueous solution, Bioresource and Technology 94 (2004) 49-52.
[15] Y. Bulut, N. Gozubenli, H. Aydyn, Equilibrium and kinetics studies for adsorption of direct blue 71 from aqueous solution by wheat shells, J. Hazard Mater. 144(2007) 300-306.
[16] Y. Bulut, Z. Baysal, Removal of Pb(II) from waste water using wheat bran, J. Environ. Manage. 78 (2006) 107-113.
2. Taibah University, Faculty of Science, Al-Madinah Al-Munawarah, KSA
Received: December 03, 2011 / Accepted: December 29, 2011 / Published: February 25, 2012.
Abstract: The efficiency of grounded date stone (Phoenix dactylifera L.) as biosorbent for water remediation was investigated. The sorption of Saudi Arabia date stones is supposed to take place mainly by electrostatic attraction between negatively charged stones surface and metals. The stone surface is negative because of translocation of sugars and proteins (containing N, S and P) from dates to stones. Various physicochemical parameters that influence the speciation and mobility of metal contaminants such as pH, contact time, adsorbent mass, and adsorbate initial concentration was applied. The general trend is that the metal uptake increases when the pH increases.
Key words: Date stone, extraction, heavy elements, adsorbent mass, contact time.
1. Introduction??
Ground, surface, and processing water frequently contain dissolved heavy metals that may arise from operations of mines, factories, and other industries. These metals are frequently difficult and expensive to remove. Metal-contaminated waters may include ions of copper, zinc, nickel, lead, cadmium, mercury, chromium, and uranium. All of these elements have toxicity to animals, plants, and other organisms or may deleteriously affect sensitive environments. In addition, even more innocuous materials may have low limits for discharge under certain conditions. A variety of reactions may occur which influence the speciation and mobility of metal contaminants including acid/base, precipitation/dissolution, oxidation/ reduction, sorption or ion exchange. Precipitation, sorption, and ion exchange reactions can retard the movement of metals in groundwater. The rate and extent of these reactions will depend on factors such as pH, Eh, complexation with other dissolved constituents, sorption and ion exchange capacity of the geological materials, and organic matter content. Ground-water flow characteristics also influence the transport of metal contaminants. Adsorption onto activated carbon is very effective method for metal removal but its use is limited because of high cost. Biosorption, the passive uptake of heavy metals by biomaterials, can be both highly efficient and of low cost. The date (Phoenix dactylifera L.) has been an important crop in arid and semiarid regions of the world. It has always played an important part in the economic and social lives of the people of these regions. Saudi Arabia is considered to be one of the date producing countries; the number of these trees is estimated to be over 4 million and around 100,000 tons of dates are produced annually. Biosorbent is defined as one which is abundant in nature, or is a by-product of waste material from industry or agriculture such as orange wastes [1], olive stones [2], papaya wood [3], grape stalk waste, peas,
inferred that the percent removal of metal ion increases with increasing adsorbents doses from (0.1-0.2 g) for lead and (o.1-0.8) for copper. After that there were non significant increases in removal percentages. This suggests that after a certain dose of adsorbent, the maximum adsorption is attained and hence the amount of ions bound to the adsorbent and the amount of free ions remains constant even with further addition of the dose of adsorbent. The increase in removal percentage with increase in adsorbent dose is due to the greater availability of the exchangeable sites or surface area at higher concentration of the adsorbent.
3.1.5 Potentiometric Measurements
The samples under treatment were measured by the selective sensor [9] for Cu metal ions and the results obtained were in agreement with that obtained with that of AAS.
4. Conclusions
The aim of this paper is to assess the ability of date stone to adsorb Cu(II) and Pb(II) ions from aqueous solutions. The effect of the solution pH, contact time and adsorbent dosage on the removal these ions was studied. Taking into consideration of the above results, it can be concluded that the date stone is a suitable adsorbent for the removal of Cu(II)and Pb(II) ions from aqueous solution in terms of low cost, natural and
We would like to extend our thanks and appreciation to The Deanship of Scientific Research, Taibah University, KSA for supporting this project by grant No. 431/700.
References
[1] A.B. Prez-Marin, A. Ballester, F. Gonzlez, M.L. Blzquez, J.A. Muoz, J. Sez, et al., Study of cadmium, zinc and lead biosorption by orange wastes using the subsequent addition method, Bioresource Technology 99 (17) (2008) 8101-8106.
[2] G. Blazquez, F. Herna′inz, M. Calero, L.F. Ruiz-Nunez, Removal of cadmium ions with olive stones: the effect of some parameters, Process Biochemistry 40 (2005) 2649-2654.
[3] S. Asma, A.M. Washeed, I. Muhammed, Removal and recovery of heavy metals from aqueous solution using papaya wood as a new biosorbent, Separation and Purification Technology 45 (2005) 25-31.
[4] H. Bena?ssa, Screening of new sorbent materials for cadmium removal from aqueous solutions, Hazardous Materials 132 (2006) 189-195.
[5] S. Schiewer, S.B. Patil, Pectin-rich fruit wastes as biosorbents for heavy metal removal: Equilibrium and kinetics, Bioresource Technology 99 (2008) 1896-1903.
[6] G.H. Pino, L.M.S. De Mesquita, M.L. Torem, G.A.S. Pinto, Biosorption of cadmium by green coconut shell powder, Minerals Engineering 19 (2006) 380-387.
[7] E. Augustine, H. Yuh-Shan, Effect of pH on cadmium biosorption by coconut copra mea, Hazardous Materials 139 (2007) 356-362.
[8] F. Pagnanelli, S. Mainelli, F. Veglio, L. Toro, Heavy metal removalby olive pomace: Biosorbent characterization and equilibrium modeling, Chemistry Engineering of Science 58 (2003) 4709-4717.
[9] W.H. Mahmoud, A.H. Kamel, M.S. Mostafa, Response characteristics of copper- selective polymer membrane electrodes based on a newly synthesized macrocylcic calix[4]arene derivative as a neutral carrier ionophore, Electroanalysis 22 (2010) 2453-2459
[10] S.A. Al-barrak, S.M. Elsaid, Pesticides Removal from drainage Waste water using some agriculture wastes, Pakistan Journal of biological Science 8 (3) (2005) 374-378.
[11] P. Lodeiro, J.L. Barriada, R. Herrero, M.E. Vicente, The marine macro algae Cystoseira baccata as biosorbent for cadmium(II) and lead(II) removal: kinetic and equilibrium studies, Environmental Pollution 142 (2006) 264-273.
[12] C.F. Baes, R.E. Mesmer, The hydrolysis of cations, Wiley, New York, 1976.
[13] R.M. Smith, A.E. Martell, Critical stability constants, Plenum Press, New York, 1976.
[14] B. Stephen, N. Sulochana, Carbonised jackfruit peel as an adsorbent for the removal of Cd (II) from aqueous solution, Bioresource and Technology 94 (2004) 49-52.
[15] Y. Bulut, N. Gozubenli, H. Aydyn, Equilibrium and kinetics studies for adsorption of direct blue 71 from aqueous solution by wheat shells, J. Hazard Mater. 144(2007) 300-306.
[16] Y. Bulut, Z. Baysal, Removal of Pb(II) from waste water using wheat bran, J. Environ. Manage. 78 (2006) 107-113.