Effective removal of heavy metals andEffective removal of heavy metals anddyes from drinking water utilizingdyes from drinking water utilizingbio-compatible magnetic nanoparticlebio-compatible magnetic nanoparticleDepartment of Microbiology, University of Kalyani,Kalyani – 741235, West Bengal, India.
Aim & Objective :Aim & Objective :Here we investigated the use of magneticnanoparticles for removal of heavy metal(Cr) and dyes (MG) from drinking water ina cost-effective, rapid, environment friendlyway.
1. Synthesis and characterization of ironnanoparticle by a novel technique.2. Reactivity of as synthesized particle onmicrobial growth for bio-compatibilityproperties.3. Potentiality of the surface modified particletowards removal of heavy metals (e.g – Cr) anddyes (e.g – Malachite Green (MG)) from water.
1. Synthesis of iron nanoparticle by a1. Synthesis of iron nanoparticle by anovel technique:novel technique:Same volume of FeSO4 and KNO3 are taken in a tube.The mixture was reduced by 8(M) ammonia solution.A black slurry was produced.Nanoparticles were separated using magneticdecantation and washed with methanol.The nanoparticles were kept in methanol andsurface modified accordingly for various applications.
Characterization of the synthesizedCharacterization of the synthesizediron nanoparticle :iron nanoparticle :As synthesized iron nanoparticles were characterized usingTEM, SEM and Zeta potential (ζ) of it was also measured.From TEM image the size of the iron particle was found tobe 6 to 7 nm.SEM image implied amorphous nature of the nanoparticlewhich is again supported by the SAED pattern analysis.Zeta potential (ζ) of the particle was found to be –26.9 mV.
SAED pattern of iron nanoparticle TEM image of iron nanoparticleZeta potential data of iron nanoparticleSEM image of iron nanoparticle
Surface modification of iron nanoparticle –Synthesis of Glutathione coated iron nanoparticle :It was prepared by slowly adding 1 g of iron nanoparticle in 30 mMglutathione solution (pH – 9) under steering condition (2000 rpm).Synthesis of Sodium Dodecyl Sulfate (SDS) coated ironnanoparticle :For SDS coating 5% (w/v) SDS solution was prepared in water andto it 1 g of iron nanoparticle was added slowly under steeringcondition (515 rpm).
UV-Vis spectrophotometric data demonstratingthe surface fictionalization of iron nanoparticle bySDS and GSH with control :
2. Bacterial growth experiment :2. Bacterial growth experiment :The comparative study on growth ofbacteria under normal condition andunder the influence of magneticnanoparticle was carried out.Various concentration of nanoparticles(i.e 100 μg/mL, 200 μg/mL ) wereadded into 50 mL LB mediumcontaining E. coli DH5α (a) and B.subtilis (b) separately, along withcontrol to track the normal microbialgrowth . Optical density measurementat 600 nm indicated the bacterialgrowth interacting with nanoparticleand the viability was determined froma plot of the log of the optical densityversus time.
3. Potentiality of the surface modified3. Potentiality of the surface modifiedparticle towards removal ofparticle towards removal ofA) heavy metals (e.g – Cr)A) heavy metals (e.g – Cr)andandB) dyes (e.g – Malachite Green (MG))B) dyes (e.g – Malachite Green (MG))from water.from water.
A) Uptake studies of Chromium (VI)A) Uptake studies of Chromium (VI)in batch process :in batch process :Cr(VI) uptake studies have beenperformed using glutathionated ironnanoparticles. Adsorption studieswere performed by adding differentconcentration (0.1 – 1.0 µg/mL) ofpotassium di-chromate to 100µg/mL,200µg/mL and 400µg/mL of GSH-loaded iron nanoparticles separately(at pH 7). After desired incubation (24h at 37 ± 2 °C) Cr(VI) loadednanoparticles were separated withmagnetic decantation and thesupernatant has been analyzed forCr(VI) concentration using Cr(VI)specific colorimetric reagent S-diphenylcarbazide (DPCZ).
Effect of pH on Cr(VI) adsorption :Effect of pH on Cr(VI) adsorption :Chromium(VI) absorption by the GSH-iron nanoparticle was evaluatedat different pH (3, 11).
B) Absorption studies of Dye (MalachiteB) Absorption studies of Dye (MalachiteGreen – MG) using SDS coated ironGreen – MG) using SDS coated ironnanoparticle :nanoparticle :MG uptake studies were performed ina batch process. Adsorption studieswere performed by adding watersample containing MG to SDS-loadediron nanoparticles . At pH 3.0 theadsorption was highest . Afterincubation (24 hr) the MG loadednanoparticles were separated withmagnetic decantation. Concentrationof MG in the supernatant wasmonitored spectrophotometrically bymeasuring the absorbance of thesolution at 627 nm.
Conclusion :Conclusion :Our preliminary study of heavy metal removal (Cr(VI)) and dye(MG) removal using surface functionalized iron nanoparticleshowed excellent efficiency. This novel and convenient procedureis safe, rapid and inexpensive for adsorption and removal oftoxic compounds from water compared to the other troublesomemethods.Further study to optimize the adsorption efficiency should beperformed that would develop cost effective, reusable platformto mitigate the pollution.
The research work has been carried out with the financial support ofUniversity Grant Commision, Govt. of India(Major Research Project-41-1178/2012(SR))andUniversity of Kalyani, Nadia, West Bengal.Acknowledgement :Acknowledgement :
References :References :1) A. Afkhami, R. Moosavi, T. Madrakian; Talanta, 2010 ,785: 82.2) W. Zhang;Journal of Nanoparticle Research, 2003, 323: 5.3) Chatterjee S, Bandyopadhyay A , Sarkar K ; 2011 , Journal ofNanobiotechnology. 9:34.4) Urone. PF ; 1955, Anal. Chem. 27: 1354–1355.5) Culp SJ, Beland FA ; 1996. J. Am. Coll. Toxicol. 15: 219-238.6) Hiraide M, Sorouradin MH, Kawaguchi H ; Anal. Sci, 1994, 10: 125-128.