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1 ISSN: X CODEN: IJPTFI Available Online through Research Article REMOVAL OF NITRATE IONS BY NANO-PARTICLES OF ZERO VALENT IRON MAGNETIC BY SPECTROPHOTOMETER Narges Chamkouri* Abadan School of Medical Sciences, Abadan, Iran. Received on Accepted on Abstract In this study, a simple and sensitive spectrophotometric method was proposed for the removal of nitrate from water samples by nano-particles of zero valent iron magnetic as the adsorbent. The influence of variables on, including ph, amount of adsorbent, contact time, temperature, and centrifugation time were investigated and optimized. Under the optimum conditions, the calibration graphs are linear in the range of mg L -1, relative standard deviations (RSD) less than 5% (n= 3), detection limit of 0.1 mg L -1, and removal of nitrate ion in water samples was in the ranges of 87-96%. The method was successfully applied for removal of nitrate ion in water samples. Keywords: Nitrate, nano-particles of zero valent iron magnetic, spectrophotometer. Introduction The chemical contamination in food and water have raised public and scientific interest due to their dangerous effects on human health [1]. Water is important sources of uptake the essential material by body of human, but its quality has a great impact on human health. Toxic pollutants and heavy infiltration of water are causing human health and disease organisms. Nitrate is one of the most common chemical contaminant for both plant growth and nitrogenous fertilizers are routinely applied to agricultural lands worldwide to increase crop production [2]. Nitrite is not ordinarily found in high concentration in either surface water or in groundwater, but can be presented as an intermediate step in the oxidation of ammonia or in the reduction of nitrate. Nitrate contamination of surface water and groundwater in many parts of the world leads to environmental problems [3]. Biological reduction of nitrate to nitrite in the body can lead to illness in children aged less than six months is metoglobin disease [3-4]. Some studies have shown that pregnant women who drink water with high nitrate concentrations have been used; the incidence of malformations in infants at high risk of miscarriage, and decreased oxygen delivery to the baby through the mother's IJPT Sep-2015 Vol. 7 Issue No Page 9116

2 blood is effective and in case of water with high nitrate concentration is about 29 ppm to 75 percent increased risk of miscarriage in pregnant women and may increase the risk of bladder cancer in women [5-6]. However, the continuous ingestion of nitrite can have serious implications for animal and human health [5-8]. In recent years, nanotechnology has been developed as an important technology for water treatment. Zero-valent iron nanoparticles, a high capacity for recovery of ph and nitrate removal from water resources and environment play a role in the removal of these ions. Iron zero by taking oxygen from nitrate to reach higher capacities and the nitrogen gas is converted to iron precipitation. Zero-valent metals in polluted water are factors for reform, among these metals, the use of zero-valent iron (NZVI) due to the abundance of cheap, non-toxic and capable of rapid response and high efficiency in the analysis of priority pollutants [7]. Schoemen et al. showed in a study on water, iron-containing compound is a method for nitrate removal. In this study it was found that the particle size is smaller and therefore much more reactive nanoparticles with nitrate ion removal rate are increased [8]. Huang and colleagues showed in a study of zero-valent iron nitrate removal at ph equal 4 was over 90% [9-13]. In this work, adsorption feasibility of NZVI has been assessed for nitrate removal from aqueous solution. The influence of variables, including ph, amount of adsorbent, contact time, temperature, and centrifugation time were investigated and optimized. The proposed methods were successfully applied for the removal of nitrate from water by spectrophotometer. Experimental Instrumentation A double beam spectrophotometer (PG Instruments, model T80 + UK) was used. PH value measurements were performed on a ph meter (Metrohm, model 827, Switzerland) using a combined glass electrode. Before application, the ph meter was calibrated with standard buffers (ph=4.0 and ph=7.0). Deionized water was obtained from Milli-Q (Bedford, MA, USA) and used in all experiments. The final ph was adjusted by adding 1.0 M hydrochloric acid or sodium hydroxide solutions. Materials and reagents: All reagents were used analytical grade and were purchased from Merck (purity higher than 99%). Deionized water was obtained from Milli-Q (Bedford, MA, USA) and used in all experiments. The ph buffer solutions were prepared from sodium dihydrogen phosphate (0.02 mol L -1 ). A stock solution 3000 mg L -1 was prepared by dissolving phenol red in water. Working solutions at the concentration of 2500 mg L -1 were prepared by diluting appropriate volumes of the standard stock solutions with deionized water. IJPT Sep-2015 Vol. 7 Issue No Page 9117

3 Nitrate removal studies: Removal of nitrate was investigated by batch experiments. A stock nitrate solution 2500 mg L -1 was used in removal experiments. Working solutions at the concentration of 2500 mg L -1 were prepared by diluting appropriate volumes of the standard stock solutions with deionized water. A fixed amount of the nano particle was added to nitrate solution and was taken in a 25 ml beaker. The solid part was centrifuged for 4 min at 3500 rpm. Properties of Nanoparticles: Magnetic nanoparticles of zero-valent iron made in this study have a purity of 95%, the size of nanoparticles and 8-18 nm, m 2 g-specific surface shape is spherical. Results and Discussion In order to optimize the analytical variables was optimized by one-at-a time method. In this method influence of variables including, ph, amount of adsorbent, contact time, temperature, and centrifugation time were investigated and optimized. Investigation the ph effect: ph is an important factor influencing nitrate removal. One of the main parameters controlling the ph of the reaction of nitrate ion is removed. For determining the ph of the reaction of nitrate by zero-valent iron is related to the following factors are considered. 1 - Being directly involved in ion H + 2- H + ions on the absorption of iron nitrate levels affect the active sites 3 - How to make a large extent influenced by the solution ph [13]. Nitrate removal rate increased with increasing ph to 3 and then nitrate removal rate decreases. Iron oxides are positively charged at low ph, such as nitrates better absorb negative ions in high ph can cause adsorption of cations [14-17]. In order to investigate the effect of ph on nitrate adsorption, the ph of the nitrate solutions (50 mgl -1 ) were adjusted from According to the obtained results, it can be concluded that the nitrate adsorption was increased when the sample ph was decreased to 3.0. The results are shown in Fig. 1. Finally, ph of 3.0 was chosen as the optimum ph sample solution for the following experiments. Nitrate removal rate increased with increasing ph to 3.0 and then nitrate removal rate decreases. The result is shown in Fig.1. IJPT Sep-2015 Vol. 7 Issue No Page 9118

4 Figure-1: Effect of ph solution. Different amount of adsorbent The results indicated that the quantitative removal rate of nitrate was obtained in the range of g. Therefore, 1.2 g of nano-adsorbent was used for further experiments. The results are shown in Fig. 2. Figure-2: The amount of adsorbent. Contact time of the adsorbent The nitrate removal by the nanostructures was investigated as a function of contact time. It was fund that removal of nitrate increased with time. Effect of contact time on the recoveries was examined in the range of 0-5 min. The maximum removal rate was obtained 4 min. Therefore, 4 min was found to be the optimum contact time. The results are shown in Fig. 3. Figure-3: Evaluation of sorbent contact time. IJPT Sep-2015 Vol. 7 Issue No Page 9119

5 Evaluation Solution Temperature Narges Chamkouri* et al. International Journal Of Pharmacy & Technology Preformance of the proposed method at different temperature was evaluated. The effect of temperature on the removal rate was evaluated over different temperatures ranging from 10 ºC - 35 ºC. In our study, the contact surface between extraction solvent and the aqueous samples is very large and there is no limiting any effect caused by slow mass transfer. Therefore, this is clear that temperature cannot affect the removal rate. Finally, 25 ºC was taken to be the optimum temperature. In higher temperature, recoveries decreased. The results are shown in Fig. 3. Figure-4: Evaluation Solution Temperature. Concentration of nitrate in contact with the adsorbent Iron nanoparticles increases with increasing concentration and solution ionic strength nitrate removal rate increases. According to studies carried out in various concentration of nitrate solution with the highest efficiency absorbent absorbent concentration is 20,000 mg L -1. The results show that the sorbent sorbent performance in all areas of fairly high concentrations of nitrate removal was investigated. Low concentrations of nitrate ion, nitrate ion transport in the nanoparticles can be done more efficiently. Figure (5) Figure-5: Evaluation of the nitrate solution. IJPT Sep-2015 Vol. 7 Issue No Page 9120

6 Effect of foreign ions The influence of foreign ions that might be adsorbed on the nano investigated in order to identify potential interferences. Effect of alkaline, alkaline earth and transition metal ions and some anions on complex formation of nitrite with nano was investigated. The tolerance limit for a foreign ion was taken as the largest amount of the ions that could be present with the nitrite and gives the adsorption within 5% of that of the nitrite ions alone.the degree of tolerance for some alkaline, alkaline earth and transition metal ions are presented in Table 1. Table 1.Tolerance limits in the concentration of 50 mg L -1 of nitrate (relative error ± 5.0%). Foreign Tolerance limit ng L -1 SO 2-4, SO 2-3, Co 2+, 3- PO AS 3+, Sb 3+, Pb 2+, Cd Hg 2+, Cu 2+, Mn 2+, Fe Li +, K +, NH 4 +, CO 3 2- Ca 2 +, NO 3 -, C 2 O Analytical figures Analytical figures of merit including, limit of detection (LOD), and RSD. Under the optimal conditions obtained above, the analytical performance of the proposed method was investigated. Under the optimum conditions, the calibration graphs are linear in the range of mg L -1. The limit of detection (LOD) determined as three times the standard deviation of 10 blank measurements divided by the slope of the calibration curve was less than 0.1 mg L 1. The relative standard deviation (RSD) was less than 5%. The correlation coefficients (R) for all calibration curves were The accuracy of the proposed method was estimated by determining the recoveries of the analytes by spiking experiments. Removal rate of nitrate in real and synthesis samples The predictive ability of method was determined using several water samples. The results obtained water samples (W1-W4) are summarized in Table 2. The results showed that satisfactoryies could be obtained using the recommended method. The data obtained by this method revealed the ability of this method in the removal nitrate from water samples. IJPT Sep-2015 Vol. 7 Issue No Page 9121

7 Table-2. Added and Found nitrate concentration (mg L -1 ) in real samples (W1-W4). Samples drinking water mineral water W1 Added 0 0 Found Removal% W2 Added Found Removal% W3 Added Found Removal% Conclusions W4 Added Found Removal% Today, nanoparticles are very efficient in removing toxic and heavy metals. NZVI has a high capacity for reduction of nitrate and its removal from water resources. ph is one of the basic parameters controlling nitrate reduction reaction. The advantages of this this method including recoveries in water samples was in the ranges of 87-96%. Calibration curve are linear in the range of mg L -1, relative standard deviations (RSD) less than 5% (n= 3), detection limit of 0.1 mg L -1, operation in room temperature, lower contact times and the use of simple and inexpensive method. It was demonstrated that the method could effectively be used with a simple UV Vis spectrophotometer, which allows a large number of samples to be generated on a day-to-day basis for environmental or industrial applications, such as water analysis. Finally, the method has been successfully applied for removl of Nitrate ion in water samples. References 1. A. Nuhoglu, T. Pekdemir, E. Yildiz, B. Keskinler, G. Akay, Drinking water denitrificationby a membrane bioreactor, Water Res. 36 (2002) A. Liu, M. Ming, R.O. Ankumah, Nitrate contamination in private wells in ruralalabama, United States, Sci. Total Environ. 346 (2005) IJPT Sep-2015 Vol. 7 Issue No Page 9122

8 3. Haiping Luo,Prevention of iron passivation and enhancement of Nitrate reduction by electron supplementation, Chemical Engineering journal 160(2010) (Journal Paper). 4. Ya Hsuan Liou a,shang-lien Loa,Chemical reduction of an unbuffered Nitrate solution using catalyzed and uncatalyzed nanoscale iron particles, Journal of Hazardous Materials B127(2005) Ya Hsuan Liou a, Shang-Lien Loa,Chemical reduction of an unbuffered Nitrate solution using catalyzed and uncatalyzed nanoscale iron particles, Journal of Hazardous Materials B 127(2005) I.F. Cheng, R. Muftikian, Q. Fernando, N. Korte, Reduction of nitrate to ammoniaby zero valent iron, Chemosphere 35 (1997) Y.H. Huang, T.C. Zhang, Effects of low ph on nitrate reduction by iron powder,water Res. 38 (2004) Y.M. Chen, C.W. Li, S.S. Chen, Fluidized zero valent iron bed reactor for nitrate removal, Chemosphere 59 (2005) ChoeS, Liljestrand HM,Khim J. Nitrate reduction by zero-valent iron under different ph regimes. Applied Geochemistry2004; 19(3): Jiang Z L,Zhang W, Qiong DU, et al.nitrate reduction using nanosized zero-valent iron supported by polystyrene resins Role of surface functional groups. Water research 2011;23(8):1-8003; 15: Li X D, Elliott W,Zhang XW. Zero-valent iron nanoparticles for abatement of environmental pollutants: Materials and engineering aspects. Critical reviews in solid state and materials sciences 2006; 31(4): ChoeS, Liljestrand HM,Khim J. Nitrate reduction by zero-valent iron under different ph regimes. Applied Geochemistry 2004; 19(3): Jiang Z L,Zhang W, Qiong DU, et al.nitrate reduction using nanosized zero-valent iron supported by polystyrene resins: Role of surface functional groups. Water research 2011;23(8): Xiang W. An overview. Nanoscale iron particles for environmental remediation. Nanoparticle Research 2003;5: Schoeman JJ, Steyn A. Nitrare removal with revers Osmosis in a rural area in South Africa.Desalination 2003; 15: Corresponding Author: Narges Chamkouri narges.chamkouri@gmail.com IJPT Sep-2015 Vol. 7 Issue No Page 9123