Showing 10 results for Samadi
A Rahmani, R Norozi, M.t Samadi, A Afkhami,
Volume 1, Issue 2 (10 2009)
Abstract
Background and Objectives:Groundwater treatment by nano particles has received increasing interest in recent years. Chromium is a commonly identified contaminant in soils and groundwater. Zero-valent iron, as a natural reduction agent can be used in controlling of contaminated sites. The aim of this research is investigation of hexavalent chromium removal from aqueous solutions by using of iron nano particles the effective parameters. Materials and Methods: In this research the synthesized of the iron nano particles has performed by addition of NaBH4 to FeCl3·6H2O solution and Cr(VI) reduction efficiency in Batch system was studied. Also the impact of the important field parameters including pH, initial chromium concentration, nano zero valent iron concentration and retention time were investigated.
Results:The results of this research showed that synthesized particles were in nano scale. In pH=3, chromium inlet concentration of 10 mg L-1, nano zero valent iron concentration 0.5 g L-1 and 2 minute retention time, 100% of Cr(VI) was removed.
Conclusion:The concentration of nano zero valent iron had significant effect on the reduction of Cr(VI).The reaction occurred in a wide range of pH value and the reaction efficiency increased significantly with decreasing initial pH. The significant removal efficiency, high rate of process and short reaction time were showed that iron nano particles have significant potential in removal ofCr(VI) from contaminated water.
A.h Sayyahzadeh, M.t Samadi,
Volume 2, Issue 2 (16 2009)
Abstract
Backgrounds and Objectives: Municipal Solid Waste (MSW) management and planning without adequate and reliable data about its physical components and generation rate are not obtainable. Because of MSW collection and landfilling expenses, in last decades, reuse and recycle of its components as an environmental object have been considered.
Materials and Methods:In this research, in order to determine the possibility of source recycling application in Malayer and physical composition of MSW, samples were taken by Truck-Load method and cluster random sampling from autumn 2006 until summer 2007 and analyzed for physical components percents. The obtained data were analyzed by One-Way ANOVA and Tuky statistical test. Also, public partnership was investigated. Public opinion deliberation was accomplished by dividing the city into several clusters. Questionnaires were filled by oral interview conversation.
Results: The results showed that average daily generation rate was 138 Tons and 0.88 Kg per person per day. The average percent of recyclable materials was about 11% of total daily generated wastes. Also 99% of residents had positive response to source recycling plans.
Conclusion: In general, by planning of enforceable reuse and recycling programmes, could avoid of 15 Tons of recyclable materials burial and save 19 millions Rials each day.
M.t Samadi, R Nourozi, S Azizian, Y Dadban Shahamat, M Zarabi,
Volume 2, Issue 3 (25 2009)
Abstract
Backgrounds and Objectives: Determination of Fluoride in drinking water has received increasing interest, duo to its beneifical and detrimental effects on health. The aim of this research is investigation of Effect of activated alumina in fluoride concentration reduction in drinking water.
Materials and Methods: Expriment in batch system and with change effective parameters such as pH(5, 7,9), equilibration time (30, 60, 90, 120 minute), initial fluoride concentration(1.4, 2, 2.4 mg/l) and activated Alumina dosage (0.1, 0.2, 0.3 gr/l) was investigated. Also found data of this research were fited with Langmuir and Freundlich models, kinetic data with pseudo- first order, pseudo- second order and modifited pseudo- first order models.
Results: The results showed that with increasing of pH of solution, removal efficiency was decreased and optimum pH was found to be in the range of 5 to 7. Also removal efficiency of fluoride was increased with increasing of adsorbent dosage and decreasing of initial concentration of fluoride. Adsorption isotherm data show that the fluoride sorption followed the Langmuir model (r2=0.98). Kinetics of sorption of fluoride onto Activated alumina was well described by pseudo- second order model.
Conclusion: The concentration of Activated Alumina had significant effect on the reduction of fluoride ions concentration in water.The higher fluoride removals were observed for batch experiments at pH=5 because no free fluoride ion is present in the solutions, and it could be casued by electrostatic interactions between the surface of alumina and the dominant fluoride species in solution The kinetic model can adequately describe the removal behaviors of fluoride ion by alumina adsorption in the batch system.
M Khodadadi, M.t Samadi, A.r Rahmani, R Maleki, A Allahresani, R Shahidi,
Volume 2, Issue 4 (9 2010)
Abstract
Backgrounds and Objectives: Water contamination by pesticides is considered as an environmentalproblem today. In terms of agricultural development and diversity of plant pests, the use of pesticides has been increasing. Hamedan province has a suitable agricultural condition, it has enjoyed significant development in this respect. Among all the cities of Hamedan province, Hamedan city has the highest rank in tiller crops. Therefore, yearly use of pesticides is increasing in this area which could be a serious threat to water resources of the city. The aim of this survey was determinaton of Organophosphorous and Carbamat pesticides residue in drinking water resources of Hamadan in 2007.
Materials and Methods: In this survey, 126 water samples were collected from 7 drinking water resources of Hamedan during 12 consecutive months in 2007. for determination of these pesticides,two methods (solid- phase extraction and Liquid-Liquid extraction) were adopted .and samples were analyzed by means of HPLC and GC/MS applying standard methods.
Results: Final results showed that the most concentration of Chlorpyrifos and Carbaryl pesticides were found to be about 3.85 ppb (part per billion) and 1.8 ppb in spring and June respectively the maximum concentration of Diazinon was about 36.5ppb in October (autumn).The minimum concentration of the three pesticides was detected in winter. According to the statistical test Two - Way ANOWA there were significant differences among pesticides concentrations in the water samples in different seasons (p<0.05) . However, there wasn't a significant difference in pesticides concentrations in surface and ground water samples(p>0.05).
Conclusion: Different studies have shown that pesticides residue concentration in water samples have a relationship with the amount of pesticides used in an area, physical and chemical refractory properties of pesticides and environmental conditions. Thus, using resistant pollutants such as pesticides will be a serious threat to health of water consumers if they are not properly controlled.
M.t Samadi, M. H Saghi, M. Shirzad, J. Hasanvand, S. Rahimi,
Volume 3, Issue 1 (3 2010)
Abstract
Backgrounds and Objectives:In Iran , indicated that the municipal landfill leachate has been one of the major problem for environment. In the operations, leachate treatment is a very difficult and expensive process. Although, young leachate can be treated easily by biological treatment, COD removal efficiency are usually low due to high ammonium ion content and the presence of toxic compounds such as metal ions. Treatment of leachate is necessary.The aim of this study is reduction of Chemical Oxygen Demond (COD) and Total Suspended Solids (TSS) from hamedan city sanitary landfill leachate by three coagulants: alum, PAC and ferrous sulfate.
Materials and Methods: This experimental study was conducted to investigate the effect of treatment of landfill leachate by a coagulation-flocculation process. The effects of different amounts of coagulant and different pH values on the coagulation processes were compared.
Results:Result shown the high efficiency for reduction of CODby PAC in pH=12 and concentration of 2500(mg/l (62.66%), and by alum in pH=12 and concentration of 1000 (mg/l) (60%) , by ferrous sulfate in pH=2 and concentration of 1000 (mg/l) (70.62%). Also result shown the high efficiency for TSS removal by PAC in pH=12 and 2500(mg/l) concentration of PAC was 58.37%, with alum in pH=2 and 1500 (mg/l) concentration of alum was39.14% , by ferrous sulfate in pH=7 and 2500(mg/l) concentration of ferrous sulfate was 35.58%.
Conclusion:The best coagulant for COD removal is ferrous sulfate.The physico-chemical process may be used as a useful pretreatment step, especially for fresh leachates, prior to post-treatment (polishing) step for partially stabilized leachates.
M.t Samadi, M.h Saghi, K. Ghadiri, M. Hadi, M. Beikmohammadi,
Volume 3, Issue 1 (3 2010)
Abstract
Backgrounds and Objectives:Phosphate discharges from domestic and industrial waste water to water bodies. High concentrations of phosphate in water stimulate the eutrophication phenomenon that causes taste and odor in water, losing dissolved oxygen and aquatic life in rivers or surface waters. Aim of this study is survey of phosphate adsorption on simple nano zeolite Y and nano zeolite Y that was modified with a cationic surfactant (HDTMA-Br).
Materials and Methods:In This study we used simple nano zeolite Y and nano zeolite Y in form of Surfactant Modified Zeolites (SMZs) using batch tests to adsorption of Phosphate fromAqueous Solutions. The adsorbants were contacted with different initial phosphor concentrations (5, 10 and 15 mg/l), pH (4, 7, 12), contact time (30, 60, 90, 120, 150 and 180 minutes) and weight of adsorbant (0.2, 0.4, 0.6, 0.8 and 1g). the extracted solution was determined for Phosphate concentration by the ammonium molybdate and tin chloride method with spectrophotometric detection at 680 nm. Results:Results of this study show that, with increase in contact time, decrease in pH, increase in zeolites concentration and decrease in initial phosphate concentration, the removal efficiency increased. And the Both isotherm of Langmuir and Freundlich models (r2 > 0.997 and r2 > 0.996 respectively) were agreement with adsorption equilibrium of phosphate. Reduced Chi-Sqr For Langmuir and Freundlich models were (0.00079) and (0.0011) respectively. Pseudo first-order kinetic models fits well with experimental data (r2>0.963).
Conclusion: From this survey, it is concluded that performance of modified nano zeolite Y for adsorption of phosphate in same conditions is better than non-modified zeolite Y. In general the modified nano zeolite Y presented a good profile for removal of phosphate. Therefore SMZs is a suitable candidate for removal of Phosphate molecules from contaminated solutions in contaminated waters.
M Shirzad Siboni, M. T Samadi, A.r Rahmani, A.r Khataee, M Bordbar, M.r Samarghandi,
Volume 3, Issue 3 (4 2010)
Abstract
Backgrounds and Objectives: Industrial wastewater included the heavy metal is one of the important sources of environmental pollution. Hexavalent chromiumand divalent nickel are founded in plating wastewater which is harmful for human health and environment. Therefore, the purpose of this research is investigation of photocatalytic removal of hexavalent chromium and divalent nickel from aqueous solution using UV/TiO2 process in a batch system.
Materials andMethods: At first, reactor was designed. Then, optimumdosage of TiO2 was obtained equal to 1 g/L, with variation TiO2 dosage at constant pH and initial concentrations of hexavalent chromium and divalent nickel. The effect of pH, contact time and initial concentration of hexavalent chromium was studied at the constant amount of TiO2 (1gr/L).
Results: The result showed that photocatalytic removal efficiency increased with increasing reaction time and TiO2 dosage. In addition, it was found that removal efficiency of hexavalent chromium was decreased by increasing initial chromium concentration and pH. But, photocatalytic removal efficiency of nickel ion was increased and decreased by increasing of pH and initial nickel concentration, respectively.
Conclusion: The results showed that UV/TiO2 was an effective method in removal of hexavalent chromium and divalent nickel from aqueous solutions
M Khodadadi, M.t Samadi, A.r Rahmani,
Volume 4, Issue 3 (1 2011)
Abstract
Background and Objectives: Water pollution by pesticides has adverse effects on the environment and human health, as well .In recent years, advanced oxidation processes, have been gone through to a very high degree for pesticides removal. Poly-Aluminum chloride (PAC) used for water treatment, can be effective on pesticides removal. The aim of this research was to study the use of UV/O3 and PAC in the removal of pesticides from drinking water.
Materials and Methods: In this descriptive- analytical survey, specific concentrations of pesticides (1,5,10,15,20 ppm)namely Diazinon, Chlorpyrifos, Carbaril were prepared through addition to deionized water. Dichloromethane was used for samples&apos extraction, samples extracted with Liquid- Liquid & Solid-phase extraction , finally entered bath reactor at pH (6,7,9) .The samples then exposed to UV/O3at contact time of (0.5,1,1.5 and 2 hours) . In the PAC pilot , the effects of various concentrations of pesticides, and PAC - ranging (12/24 and 36 ppm) were investigated for the efficacy of pesticides removal. All samples analyzed by GC/MS/MS and HPLC.
Results: It was found that in UV/O3 reactor, with the rise of pH, decrease in pesticides concentration, and rise of contact time, the efficiency of removal increased too. In the PAC pilot, increase in PAC concentration and decrease in pesticides concentration , both increased the efficiency. Besides, both of the methods showed high efficiencies in the removal of both pesticides,i-e. halogenated Organophosphorus (Chlorpyrifos) , non- halogenated Organophosphorus (Diazinon) at the degree of over (%80 ) In case of carbamate pesticides (e.g. Carbaril) efficiency was over (>%90). One-Way Anova & Two -Way Anova were used to analyze the obtained data.
Conclusion: According these results these two methods are suggested for the removal of pesticides from aqueous solutions.
Mohamad Taghi Samadi, Roghaye Nourozi, Mohamad Hadi Mehdinejad, Reza Aminzadeh,
Volume 5, Issue 4 (15 2013)
Abstract
Backgrounds and Objectives: Determination of arsenic(As) in drinking water has received increasing interest due to its detrimental effects on health. The aim of this research is to investigate effect of coating coral limestone using aluminum sulfate as an adsorbent on the arsenic(V) removal efficiency from aqueous solution.
Materials and Methods: In this laboratory scale study, we prepared coral lime granules using mesh 30 during several stages. Then, we investigated the arsenate removal efficiency under different conditions and changing main factors including pH, contact time and amount of no coated and aluminum sulfate-coated adsorbent. Moreover, we fitted our results with Langmuir and Freundlich models and kinetic data with pseudo- first order, pseudo- second order and modified pseudo- first order models.
Results: We found that increasing pH from 3 to 10 at arsenate concentration of 500 ppb and 5 g/l adsorbent and 120 min contact time, removal efficiency for no coated and coated adsorbent was reduced from 100 to 86.2% and from 100 to 92.2% respectively. Increasing concentration of both adsorbents from 1 to 5 g/l at contact time 120 min increased the removal efficiency from 76 to 99.2% and from 66.3 to 91.1% respectively. Arsenate removal efficiency was directly proportional with the amount of adsorbent and contact time and reversely proportional with the initial concentration of arsenate and pH. The removal efficiency of the coated adsorbent was more than uncoated adsorbent. Langmuir was the best sorption isotherm model for arsenate in these two processes and absorption kinetic was well described with second order models.
Conclusion: Excellent removal efficiency, cost-effectiveness process, and lack of environmentally harmful substances make application of the Persian Gulf offshore corals a reasonable adsorbent to remove environmental contaminants such as arsenate.
Z Rahmani, M Harati, Mr Rahmani, Y Poureshgh, Mt Samadi,
Volume 9, Issue 2 (9-2016)
Abstract
Background and Objective: Surfactants can be found in soaps, detergents, pharmaceutical products, personal care products, as well as in leather industries. In this study, adsorption of Sodium Dodecyl Sulfate (SDS) on magnetic multi-walled carbon nanotubes in the aqueous solutions was investigated.
Materials and methods: Surfactant concentration, adsorbent dosage, and pH values were considered as variables. Residual surfactant was measured using methylene blue method and adsorbent characteristic was determined by X-Ray diffraction and Fourier transform infrared spectroscopic analysis. Adsorption capacity, adsorption isotherm, and kinetic reaction were also investigated.
Results: Adsorption investigations demonstrated that the increase in initial SDS concentration or pH values, led to the decrease in SDS adsorption. Conversely, the same result was achieved by decreasing adsorbent dosage. After 120 min SDS adsorption became stable. By increasing in SDS concentration from 15 to 150 mg/L, adsorption capacity improved from 8 to 61 mg/g. Isotherm and kinetic data demonstrated that experimental data pursued Langmuir isotherm (R2=0.993) and pseudo-second order equation (R2=0.992).
Conclusion: Magnetic multiwall carbon nanotubes can be used as an effective and useful sorbent for SDS removal due to several advantages including: high adsorption capacity, relatively low equilibrium time, and easy separation of magnetic multiwall carbon nanotubes from aqueous solutions.
