http://blogs.najah.edu/author/emp_2105 An-Najah Blogs :: en-us Sat, 27 Jul 2024 17:01:33 IDT Sat, 27 Jul 2024 17:01:33 IDT [email protected] [email protected] http://blogs.najah.edu/staff/emp_2105/article/Efficiency-of-removal-of-cadmium-from-aqueous-solutions-by-plant-leaves-and-the-effects-of-interaction-of-combinations-of-leaves-on-their-removal-efficiencyPublished ArticlesRemoval of cadmium from aqueous solutions using 20 species of plant leaves and combinations of these leaves have been studied Several factors affecting the removal efficiency have been studied The most efficient types of plant leaves for the removal of cadmium are those of styrax plum pomegranate and walnut The interaction effect of the combined leaf samples on the efficiency of removal of cadmium has been found to be additive in combinations involving styrax plant leaves but seems to be antagonistic in all other combinations The optimum experimental conditions for removal of cadmium have been found to be at pH 41 using high concentrations of naturally dried plant leaves using ground leaves and to remove cadmium from agitated aqueous solutions The percentage of metal removed at an initial cadmium concentration of 10 mgl by the most efficient types of leaves have been found to be 85 for styrax leaves 85 for plum leaves 80 for pomegranate leaves 78 for walnut leaves and 77 for meddler leaves The presence of foreign ions or complexing agents has been found to reduce the efficiency of removal of cadmium by plant leaves About 8085 of the cadmium in charged plant leaves has been released under the influence of changing the pH of the solution addition of competing ions and the addition of EDTA The results of removal of cadmium by plant leaves have been found to follow the Freundlich adsorption isotherm first-order reaction with respect to cadmium and to have intra-pore diffusion as the rate-limiting step http:dxdoiorg101016jjenvman200701028http://blogs.najah.edu/staff/emp_2105/article/Removal-of-zinc-from-aqueous-solutions-by-dry-plant-leavesPublished ArticlesRemoval of zinc from aqueous solutions by 15 species of plant leaves was studied The maximum efficiency of removal was found to be by walnut and poplar leaves at pH 6 with a maximum removal of 82 Increasing the concentration of plant leaves increased the removal of zinc up to a limit Agitation of solution increased the efficiency of the removal process The presence of competing and complexing agents affected the removal process negatively but also positively in few cases Source: PROCESS SAFETY AND ENVIRONMENTAL PROTECTION Volume: 81 Issue: B4 Pages: 236-242 Published: JUL 2003http://blogs.najah.edu/staff/emp_2105/article/Levels-of-trace-metals-and-effect-of-body-size-on-metal-content-of-the-landsnail-Levantina-hierosylima-from-the-west-bank-PalestinePublished ArticlesLevels of four trace metals Cu Zn Cd and Pb were determined in the landsnail Levantina hierosylima from four locations in the West Bank Average concentration of the metals was 1269 42 202 and 194 ppm for Cu Zn Pb and Cd respectively Significant differences in metal concentrations were observed between snails from the four sampling sites Jerusalem Abu-Dies Qarawa and Taibeh Differences are most probably due to atmospheric fallout of metals from traffic roads and industrial facilities Effect of snail size weight and shell width on metal content was investigated for the four metals Plotting metal content against soft tissue weight resulted in significant relationships Small snails were found to be richer in Zn Cd and Pb than larger ones Regression coefficients for the relationships were 075 076 and 081 for Pb Cd and Zn respectively Copper content was directly related to body weight regression coefficient = 096 indicating that Cu concentration is independent of body weight Plotting metal content against shell width indicated similar results but with less strong correlation coefficients L hierosylima is a promising bioindicator for metal pollution and further laboratory investigations are needed in order to know more about the uptake and release of metals by this organism Journal of Environmental Science and Health Part A Volume 36 Issue 7 July 2001 pages 1373 - 1388http://blogs.najah.edu/staff/emp_2105/article/Concentrations-of-heavy-metals-in-roadside-soils-plants-and-landsnails-from-the-West-Bank-PalestinePublished ArticlesConcentrations of Cu Cd Pb and Zn were determined in roadside soil plant and landsnail samples along Nablus-Ramallah main road in the West Bank Average concentrations gg-1 dry weight of the four metals in soil samples were Cu: 238 Zn: 1283 Cd: 045 and Pb: 1499 These values were higher than those found in soil samples collected from control sites Metals in roadside plant samples were within normal levels although plants from control sites were found to have slightly less metals Different parts of a plant roots stem leaves were found to accumulate metals in different concentrations The average concentration gg-1 of metals in different plant parts were: Cu: 52 Cd: 10 Pb: 219 and Zn: 518 Average concentrations gg-1 of metals in the three roadside snails were ranging between 121-132 for Cu 18-27 for Cd 21-24 for Pb and 43-69 for Zn Snails were found to magnify Cd to serious levels 30-50 times higher than in plants and soils Lead in snails was about 10 times higher than that in plant leaves and much less than that in roadside soils Other metals in snails did not show abnormal concentrations Journal of Environmental Science and Health Part A Volume 36 Issue 5 May 2001 pages 765 - 778http://blogs.najah.edu/staff/emp_2105/article/Removal-of-Dissolved-Copper-from-Polluted-Water-Using-Plant-Leaves-11-Effects-of-Copper-Concentration-Plant-Leaves-Competing-Ions-and-Other-FactorsPublished ArticlesFactors affecting copper removal from polluted water by poplar Populus euphratica leaves were investigated and a mechanism for copper removal was suggested Increasing the amount of leaves from 5 to 25 gL increased the rate and hence the amount of copper removed Increasing the concentration of copper in solution from 2 to 20 mgL caused a corresponding increase in copper uptake per unit weight of leaves at a constant leaf concentration of 20 gL The uptake of copper ions by poplar leaves was found to be noticeably affected by the presence of other metal ions The effect of these ions could be dependent on the relative affinity of leaves to these ions and copper as well as to pH Depending on the initial concentration the presence of the chelating agent EDTA in the solution considerably reduced the rate and amount of copper uptake Fresh leaves were found to uptake much less copper than dry leaves Rough-crushing or fine-grinding of leaves slightly affected copper uptake Agitation slightly increased the rate of copper uptake and cleaning leaves did not affect its ability to uptake copper The main mechanism for copper removal by poplar leaves is most probably adsorption Other mechanisms such as complexation may play a minor role as well Intrapore diffusion is thought to be the rate-limiting step for the interaction between poplar leaves and copperionshttp://blogs.najah.edu/staff/emp_2105/article/Removal-of-Dissolved-Copper-Prom-Polluted-Water-Using-Plant-Leaves-I-Effects-of-Acidity-and-Plant-SpeciesPublished ArticlesRemoval of copper from polluted water by plant leaves was studied using 15 species Copper was recovered in variable percentages depending on the species and pH value of the solution Copper recovery from a 20 mgL copper solution ranged between 88 in poplar leaves and 33 in oak leaves For all leaves studied maximum copper recoveries were found to be between pH 4 and 6 depending on the plant species At pH 2 the copper was not removed by the plant leaves studied Adsorption was suggested as the main mechanism for the reaction between copper ions and plant leaves with a reaction order equal to onehttp://blogs.najah.edu/staff/emp_2105/article/Removal-of-cadmium-from-polluted-water-using-decaying-leaves---effect-of-acidityPublished ArticlesThe effect of pH on the removal of cadmium from aqueous solutions by dry leaves has been studied Reed leaves showed a high capability of cadmium adsorption at almost any pH The adsorption was particularly high at pH 1 Cypress oak and pine leaves showed lower adsorption of cadmium ions at low pH values and this adsorption increased steadily at higher pH values Reed and oak leaves have been found more efficient for removing cadmium from aqueous solutions than cypress and pine leaves in acidic neutral or basic media Reed was particularly efficient at very low pH which makes it suitable for removing cadmium from polluted water affected by acid rain Almost all of the cadmium present in solutions having concentrations 10mgL was removed by reed leaves within 24 hours Journal of Environmental Science and Health Part A Volume 34 Issue 4 July 1999 pages 835 - 851http://blogs.najah.edu/staff/emp_2105/article/Removal-of-cadmium-from-polluted-water-using-decaying-leaves-mdash-effects-of-type-of-leaves-and-of-concentration-of-cadmiumPublished ArticlesThe removal of cadmium from aqueous solutions by reed leaves cypress leaves oak leaves pine leaves and reed roots has been studied Reed leaves have been found efficient for removing cadmium from aqueous solutions Almost all of the cadmium present in solutions having concentrations ranging between 1 mgL and 6 mgL was removed by reed leaves within few days Pine leaves and reed roots showed only little capability for removing cadmium from aqueous solutions The results obtained on reed leaves were found to follow the Frendlich adsorption isotherm Journal of Environmental Science and Health Part A Volume 31 Issue 10 November 1996 pages 2503 - 2513http://blogs.najah.edu/staff/emp_2105/article/Effect-of-root-treatment-of-cauliflower-parsley-and-spinach-plants-with-copper-and-zinc-on-the-plant-growthPublished ArticlesThe effect of copper and zinc ions as growth - inhibitors of plants was studied by the root-treatment of cauliflower parsley and spinach plants Both copper and zinc showed an obvious growth-inhibition effect on the growth of the studied plants as well as on their various parts The sensitivities of cauliflower parsley and spinach plants towards treatment with copper and zinc solutions were compared between each other as well as between their various parts The toxicity effects of zinc and copper on the growth of plants were compared Copper showed higher toxic effect on the growth of treated cauliflower spinach and parsley plants as well as on the growth of the various parts of treated plants Journal of Environmental Science and Health Part A Volume 30 Issue 10 December 1995 pages 2123 - 2132http://blogs.najah.edu/staff/emp_2105/article/Growth-metal-uptake-and-uptake-distribution-of-spinach-and-parsley-plants-irrigated-with-copper-solutionsPublished ArticlesThe effects of irrigation of spinach and parsley plants with copper solutions on plant growth and on metal uptake by plant were studied Copper was found to inhibit the growth of spinach and parsley plants The growth of spinach plants was more inhibited by treatment with copper than parsley plants Both copper concentration and the total content of copper in treated plants increased with the increase of concentration of copper in solutions used for treatment The copper content was highest in the leaves in comparison with the other parts of treated plants Only very small portions of the added copper were allowed to be translocated from soil into plant Journal of Environmental Science and Health Part A Volume 30 Issue 9 October 1995 pages 2057 - 2069http://blogs.najah.edu/staff/emp_2105/article/Effects-of-several-factors-on-the-growth-and-on-the-metal-uptake-and-uptake-distribution-of-okra-plant-treated-with-cadmiumPublished ArticlesSeveral factors affecting the growth and the uptake of cadmium by okra plants were studied using both root - treatment and foliar - treatment These factors were the concentration of cadmium type of treatment soil composition presence of foreign ions salinity acidity and temperature Both growth of plant and cadmium uptake by plant were affected highly by the concentration of cadmium type of treatment soil composition salinity and temperature Acidity of solutions has only a little and irregular effect A synergistic combined effect of lead copper and zinc with cadmium was observed on the growth of plant but not regular on the uptake of cadmium Journal of Environmental Science and Health Part A Volume 30 Issue 9 October 1995 pages 2027 - 2040http://blogs.najah.edu/staff/emp_2105/article/Effects-of-several-factors-on-the-growth-and-on-the-metal-uptake-distribution-of-pepper-plants-treated-with-cadmiumPublished ArticlesSeveral factors affecting the growth and the metal uptake of pepper plants treated with cadmium solutions have been studied These include concentration of cadmium type of treatment type of soil plant species and some properties of solutions used for treatment such as acidity degree of salinity and temperature Cadmium had an obvious effect on the growth of pepper plants Foliar-treated plants were affected more than root-treated plants The least degree of growth-inhibition and of cadmium uptake was found in plants grown in soils with high organic matter content Various species of pepper plants acted very differently towards cadmium treatment Both growth-inhibition and cadmium uptake was increased in plants treated with acidic saline and hot solutions Journal of Environmental Science and Health Part A Volume 30 Issue 8 September 1995 pages 1659 - 1684http://blogs.najah.edu/staff/emp_2105/article/Effect-of-irrigation-with-lead-and-cadmium-on-the-growth-and-on-the-metal-uptake-of-cauliflower-spinach-and-parsleyPublished ArticlesThe effect of root-treatment of cauliflower spinach and parsley plants with lead and cadmium were studied Both metal ions showed obvious growth inhibition of treated plants with cadmium having higher toxicity on growth than lead Cadmium was more concentrated in the edible parts of the three treated plants whereas lead was more concentrated in the edible parts of cauliflower and spinach plants only Metal ion concentrations and total metal ion content of treated plants increased with the increase of concentration of cadmium or lead ions in solutions used for treatment The uptake of metal ion per unit concentration decreased in treated plants with the increase of concentration of cadmium or lead ions in solutions used for treatment Metal ion concentration and metal uptake were higher in the plants treated with cadmium than those treated with lead Journal of Environmental Science and Health Part A Volume 30 Issue 4 May 1995 pages 831 - 849http://blogs.najah.edu/staff/emp_2105/article/Removal-of-lead-from-polluted-water-using-decaying-leavesPublished ArticlesDecaying leaves have been proven capable of partially removing lead from polluted water Several factors affecting the removal process have been studied These include the concentration of lead ions concentration of leaves drying leaves degree of crushing of leaves leaf extracts pH agitation and presence of competing and of complexing agents The relative capability of some common types of leaves for the removal of lead from water has been studied The release of lead from leaves saturated with lead ions has been studied under the effect of varying pH addition of competing ions and the addition of complexing agents The results of the present work indicate that the interaction between lead ions and leaves is mainly an adsorption process and fit the Freundlich adsorption isotherm whose parameters have also been calculated A fractional order of reaction 07 has been determined for the reaction between lead ions and leaves using two methods of evaluation A mechanism in which film diffusion being the most probable limiting step has been suggested Journal of Environmental Science and Health Part A Volume 29 Issue 10 December 1994 pages 2087 - 2114http://blogs.najah.edu/staff/emp_2105/article/A-role-for-decaying-leaves-in-mitigating-the-harmful-effects-of-acid-rain-Effects-of-acidity-foreign-ions-concentration-of-leaves-and-locationPublished ArticlesDecaying leaves have been found capable of resisting the effects of acid rain via their ability to buffer water In a previous study the buffering action of five common types of leaves cypress oak pine cinchona and ficus was investigated In the present study the effects of several factors on the buffering ability of these leaves have been studied These factors are acidity presence of foreign ions concentration of leaves and location The studied factors have been found not to affect the pattern of variation of pH of the leaf suspensions with time but to affect the pH value reached by these suspensions Ficus leaves have shown a distinct copability of neutralizing acidic waters Journal of Environmental Science and Health Part A Volume 29 Issue 3 April 1994 pages 467 - 475http://blogs.najah.edu/staff/emp_2105/article/A-role-for-decaying-leaves-in-mitigating-the-harmful-effects-of-acid-rainPublished ArticlesHarmful effects of acid rain have been considered a serious problem In this paper we have studied the ability of several common types of leaves to mitigate the effect of acid rain via the ability of these leaves to act as buffers in water The pH of leaf suspensions of cypress pine oak cinchona and ficus leaves has been determined and its variation with time has been followed The buffer capacities for these leaf suspensions have also been determined at several times over a long period of time The effect of dilution on this buffer capacity has been studied The speeds at which the various leaf suspensions adjust their pH value when disturbed have been studied The capability of the various leaves studied here to act as a buffer can be arranged in the order: Ficus cypress ~ cinchona pine ~ oak Journal of Environmental Science and Health Part A Volume 29 Issue 1 January 1994 pages 115 - 127http://blogs.najah.edu/staff/emp_2105/article/Effects-of-root-and-foliar-treatments-with-lead-cadmium-and-copper-on-the-uptake-distribution-and-growth-of-radish-plantsPublished ArticlesThe effects of treatment of radish plants with cadmium lead and copper were studied Both root treatment and foliar treatment were used All three elements were found to inhibit the growth of radish plants Cadmium and lead were greater growth inhibitors than copper on the plant Effects of cadmium and copper were greater on the growth of shoots while the effect of lead was greater on the growth of roots Foliar treatment was more harmful to plant growth than root treatment The uptake of metal ions and the distribution of this uptake in the roots and shoots of treated plants were determined Cadmium and copper uptake by plant was concentrated mostly in the shoots while the uptake of lead was concentrated more in the roots of treated radish plants The amount of metal uptake increased with the increase in metal ion used in treatment of plants The amount of uptake was higher in foliar-treated plants than in root-treated plants Concentration of cadmium and lead exceeded the maximum allowed limit in foods in most cases; concentration of copper exceeded the maximum allowed limit in food only in one sample The percentage of metal ions taken up by plants from the total amount of metal ions added during treatment was very small This percentage was comparatively higher in the case of foliar treatment than in the case of root treatment It was also higher from solutions having low concentrations of metal ions than from solutions having high concentrations of metal ions Environment International Volume 19 Issue 4 1993 Pages 393-404 http://blogs.najah.edu/staff/emp_2105/article/Combined-Effects-of-Cadmium-Lead-and-Copper-on-the-Growth-and-on-Metal-Uptake-of-Broad-Beans-Carrots-Radishes-and-Marrow-VegetablesPublished Articles Toxic symptoms of plants treated with a metal ion may not always be due to the increase of the uptake of this metal by plant but might be the result of the effect of the addition of this metal on the uptake of the other metal ions by plant Thus the study of the effects of combined treatments with more than one metal is important In the present study we have studied using root-treatment and foliar-treatment the combined effect of lead cadmium and copper on the growth of broad beans radishes carrots and marrow vegetables The effect of presence of each metal ion on the uptake of the other metal ions on the various parts of the plants by both root-treatment and foliartreatment of plants have also been studied The results have shown that the combined effect of metal ions differs from one case to another with variation of the metal ions piant part of piant or type of treatment http://blogs.najah.edu/staff/emp_2105/article/Effects-on-growth-and-uptake-distribution-of-root-and-foliar-treatments-of-marrow-plants-with-cadmium-and-lead-solutionsPublished ArticlesIn this study the effects of root and foliar treatments of marrow plants with cadmium and lead solutions on the growth of the various parts of plant roots stem leaves and fruits have been studied Growth inhibition of the various parts of treated plants has been compared with each other and for the two types of treatment The toxicity of cadmium on the growth of plant has been compared with the toxicity of lead on the various parts of plants treated by root or by foliar-treatment with metal ions Cadmium and lead uptake by plants and the distribution of this uptake between the various parts of treated plants have been determined and commented on Percentages of cadmium or lead taken by plant from the total amount of cadmium or lead added during treatment have been calculated and found to be very small This percentage has been found to be higher in foliar-treated plants and from dilute solutions than in root-treated plants and from more concentrated cadmium or lead solutions Journal of Environmental Science and Health Part A Volume 27 Issue 8 December 1992 pages 2173 - 2190http://blogs.najah.edu/staff/emp_2105/article/Effects-of-root-and-foliar-treatments-of-carrot-plants-with-lead-and-cadmium-on-the-growth-uptake-and-the-distribution-of-uptake-of-metals-in-treated-plants-Published ArticlesToxicity of cadmium and lead on the growth of carrot plants has been studied Cadmium has been found to be more toxic than lead especially on the shoots of carrot plants Foliar treatment has been compared with root-treatment for the two elements on carrots and on their roots and shoots Concentrations and total contents of lead and cadmium in whole plant in roots and in shoots have been determined for treated carrot plants and compared in root-treatment with foliar-treatment Explanations have been suggested whenever possible to illucidate the results obtained Percentages of the metals taken by plants from the whole amounts of metal added during treatment have been calculated and related to type of metal used concentration of metal in solutions used for treatment and the way of treatment Journal of Environmental Science and Health Part A Volume 27 Issue 7 October 1992 pages 1739 - 1758http://blogs.najah.edu/staff/emp_2105/article/Effects-on-growth-and-uptake-of-broad-beans-Vicia-fabae-L-by-root-and-foliar-treatments-of-plant-with-lead-and-cadmiumPublished ArticlesUptake of toxic metals by plants has been of great interest to environmental scientists because this might harm the growth of plant and cause health hazard to man and animal In this study the effects of two elements lead and cadmium which cause high concern because of their cummulative nature have been studied on broad beans Both elements have been found to affect the growth of broad beans and this effect increased with the increase of concentration of metal in solutions used for root-treatment or for foliar-treatment of plant The effect of foliar-treatment was very much higher than the effect of root-treatment by lead or cadmium Cadmium was found more toxic to plant growth than lead The effect of cadmium treatment was more on the growth of fruits while the effect of lead treatment was more on the roots of broad beans The least affected part by lead or cadmium was the stem of plant Both the concentration and the whole content of metal in plants and its varoius parts roots stem leaves and fruits increased steadily with the increase of cadmium or lead concentration in solutions used for either root-treatment or foliar-treatment Concentration of metal ions was higher in roots and leaves than in fruits and stems of treated plants The uptake of metal to plant was calculated to be a very small part of the total amount of metal added during treatment Some explanations have been suggested in this study to explain the results obtained Journal of Environmental Science and Health Part A Volume 27 Issue 7 October 1992 pages 1619 - 1642http://blogs.najah.edu/staff/emp_2105/article/Uptake-of-cadmium-from-water-by-beech-leavesPublished ArticlesUptake of cadmium from aqueous solutions by beech leaves has been studied The effect of several factors on both rate and amount of this uptake has been studied These factors include concentration of leaves concentration of cadmium pH competing ions and drying leaves The pattern of the curves showing the loss of cadmium from solution has been explained Applicability of the Frendlich adsorption isotherm on the present results has been examined and the parameters of this isotherm have been calculated The order of reaction between cadmium ions and beech leaves has been determined and a mechanism for this reaction has been suggested Journal of Environmental Science and Health Part A Volume 27 Issue 3 April 1992 pages 603 - 627http://blogs.najah.edu/staff/emp_2105/article/Effect-of-competition-on-the-adsorption-of-some-ions-copper-zinc-zirconium-selenium-and-strontium-on-river---mudPublished ArticlesThe effect of presence of several ions as competing ions during the adsorption process of copper zinc zirconium selenium and strontium on river-mud has been studied The effect of concentration of competing ions on their competitive efficiencies has been concluded The competitive efficiencies of the ions studied here have been compared and arranged Journal of Environmental Science and Health Part A Volume 24 Issue 7 October 1989 pages 809 - 821http://blogs.najah.edu/staff/emp_2105/article/Spectrophotometric-Determination-of-Cobalt-II-Using-55-Dimethyl-123--Cyclohexanetrione-12-Dioxime-3--Thiosemicarbazone-Published ArticlesThe reagent 55-dimethyl-123-cyclohexanetrione 12-dioxime 3-thiosemicarbazone DCDT has been used for the spectrophotometrie determination of cobalt II Various factors affecting the sensitivity of this determination have been studied These factors include wavelength standing time and pH The range of applicability of Beers law on this determination has been concluded and its sensitivity has been calculated and compared with other reagents used for Spectroscopy Letters Volume 21 Issue 5 June 1988 pages 411 - 420http://blogs.najah.edu/staff/emp_2105/article/Effect-of-nickel-treatment-on-the-growth-of-egg-plantPublished ArticlesNickel may be a potential cause of damage to plant and a health hazard to man by being transferred to him through plant In this study the effect of nickel treatment on the growth of egg-plant has been studied Both root-applied treatment and foliar-applied treatment have been used The effect of nickel treatment on the nickel concentration in the various parts of plant has been studied The effect of nickel treatment on the total nickel content of the various parts of plant and the percentage of this nickel content from the total nickel content of the whole plant has been also looked into Journal of Environmental Science and Health Part A Volume 23 Issue 4 May 1988 pages 369 - 379http://blogs.najah.edu/staff/emp_2105/article/Removal-of-nickel-II-from-water-using-decaying-leaves---Effects-of-pH-and-type-of-leavesPublished ArticlesNickel has been known to be toxic Water becomes contaminated with nickel via several sources Thus developing ways for the removal of nickel from water is important Leaves have been proved to be capable for removing nickel from aqueous solutions This removal process has been found to be very dependent on both pH and the type of leaves Four common types of leaves have been studied over a wide range of pH The best pH and type of leaves for the removal of nickel from aqueous solutions have been concluded Journal of Environmental Science and Health Part A Volume 23 Issue 3 April 1988 pages 183 - 197http://blogs.najah.edu/staff/emp_2105/article/1-2-Quinolylazo--245-Trihydroxybenzene-as-a-Reagent-for-the-Spectrophotometric-Determination-of-Cobalt-IIPublished ArticlesThe reagent 1-2-quinolylazo-245-trihydroxybenzene QAT6 has been used for developing a method for the spectrophotometric determination of cobalt II Various factors influencing the sensitivity of this method have been studied These factors include wavelength standing time and pH The range of applicability of this method for the determination of cobalt has been determined The sensitivity of the method has been compared with other spectrophotometric mthods used for the determination of cobalt The effect of several ions as interferents with the determination of cobalt has been investigated The Composition of the Co-QATB complex its stability constant and its free energy of formation have been determined Spectroscopy Letters Volume 21 Issue 1 January 1988 pages 35 - 44http://blogs.najah.edu/staff/emp_2105/article/Explanation-of-the-Shape-of-Calibration-Graphs-Obtained-for-Mercury-Zinc-and-Copper-in-Stream-Water-SamplesPublished ArticlesCalibration graphs have been obtained for mercury zinc and copper ions using buffered pH 74 stream water and centrifuged stream water samples Two hypothesis explaining the shape of the obtained calibration graphs have been suggested; one refers the shape to the adsorption of-trace elements on the suspended particles and on the container surfaces the other hypotheses refers the shape of calibration graphs to the presence of chemical interference The strength of the two hypotheses has been compared The effect of time on the shape of the calibration graphs has also been investigatedhttp://blogs.najah.edu/staff/emp_2105/article/Effect-of-adsorption-on-calibration-graphs-obtained-for-lead-cadmium-and-copper-in-natural-water-samples-Published ArticlesCalibration graphs for lead cadmium and copper have been obtained in natural water in centrifuged natural water and in distilled water These calibration graphs were repeated in each medium one time when acidified to PH 22 and another time when buffered to pH 74 The shape of the calibration graphs obtained in the various types of media has been explained with reference to adsorption of metal ions on the suspended particles of the natural water and on the container surfaces An equation describing the adsorption process has been applied on the calibration graphs obtained for lead cadmium and copper in natural water samples The effect of time on the shape of calibration graphs has been also looked into Journal of Environmental Science and Health Part A Volume 22 Issue 2 February 1987 pages 125 - 139http://blogs.najah.edu/staff/emp_2105/article/Spectrophotometric-determination-of-cadmiumII-using-2-5-bromo-2-pyridylazo-5-diethylaminophenolPublished ArticlesThe complex of cadmium with the reagent 2--5-bromo-2-pyridylazo-5-diethylaminophenol 5-Br-PADAP has been studied The composition stability constant and free energy change of formation of the complex have been determined A sensitive spectrophotometric method for the determination of cadmium has been developed and applied for a range of concentration of 0440 gml cadmium using the complex Cd-5-Br-PADAP The optimum conditions for maximum sensitivity of determination such as standing time pH wavelength and order of addition have been determined The effect of foreign ions on this method has been also studied Microchemical Journal Volume 34 Issue 3 December 1986 Pages 251-253