Abstract
In this work, an anodized porous alumina (APA) membrane has been proposed to remove heavy metal ions from water samples between the 10 nM to 1 mM concentration range through ion concentration polarization. The results have been verified by monitoring the change in current for different concentrations of heavy metal ions in water samples using chronoamperometryand linear sweep voltammetry at a minimal potential value. This device can remove excess amount of heavy metal ions at the surface levels of water bodies by using a miniaturized device array and a potential source. The device can also be reused using a square wave voltammetry after stripping the pre-deposited ions.
Introduction
Materials and Methods
References
[1] S. Yassin and J. F. Martonik, “Urinary Cadmium Levels in the U.S. Working Population, 1988–1994,” Journal of Occupational and Environmental Hygiene, vol. 1, no. 5, pp. 324–333, May 2004
[2] O. Faroon et al., “Toxicological Profile for Cadmium,” Agency for Toxic Substances and Disease Registry, Atlanta, GA, 7440-43–9, Sep. 2012.
[3] P. Vinayak, V. Maharshi, B. Mitra, and M. Singh, “REGENERABLE ANODIZED POROUS ALUMINA DEVICE AND A METHOD OF FABRICATION THEREOF,” Jun. 02, 2022. Indian patent application no. 202211031722
Acknowledgement
P.V. and V.M. acknowledge Ph. D. fellowship support from the Ministry of Human Resources & Development (MHRD). M.S. acknowledges support from the Department of Science & Technology (TMD/CERI/BEE/2016/035(G)). B.M. and M.S. acknowledge support from Digital Indian Corporation (Young Faculty Research Fellowship). All authors acknowledge access to facilities in the Department of Chemistry, Nanoscale Research Facility (NRF) and the Central Research Facility (CRF).
Conclusions
The anodized porous alumina shows efficient removal of heavy metal ions from water samples in a wide 10-3 to 10-8 M concentration range by at least 30 %. The device can be used for the onsite removal of heavy metal ions from water bodies by changing the area of the device or by forming an array of devices to increase its efficiency.
Department Name
Industrial Significance
Anodized porous alumina-based devices are an efficient alternative to traditionally used techniques for removing heavy metal ions from contaminated and tap water samples. The device is energy efficient, and the water wastage is significantly less than the RO systems used for water purification.
Technology Readiness Level: 7
Reusable porous alumina-based device for removal of heavy metal ions from water bodies and effluents discards
Priya Vinayak, Vikram Maharshi, Madhusudan Singh, Bhaskar Mitra
Department of EE, IIT Delhi
Result
Industry Day Theme # {HealthCare}
Table 1. Limits set by various agencies for heavy metal ions in different sources1-3.
Fig 1. Impact of heavy
metal ions over human body
Fig 2. Area of application : Contaminated water bodies and fresh water bodies and different techniques to remove heavy metals
Adsorption
Reverse Osmosis
Heavy Metal Removal
Ion Exchange Membrane
Ion
Concentration Polarization
Membrane Filtration
Electrodialysis
Chemical Precipitation
Fig 2a. Device Fabrication, b) Anodization Process
c) Cross sectional FESEM and FESEM image of anodized porous alumina
Fig 3. Mechanism of removal of heavy metal ions from water using anodized porous alumina device through ion concentration polarization
Fig 4a). Removal of lead ions from water samples using linear sweep voltammetry 4b) Electrochemical impedance spectroscopy data at different applied voltages to demonstrate the effect of applied bias over the removal of lead ions from water.
Fig 4a). Removal of copper ions from water samples using chronoamperometry (current change with concentration indicates the removal of copper ions from water) 4b) FESEm image of high concentration copper deposited over anodized porous alumina(FESEM indicates the growth of copper in pores at higher concentrations) 4c) EDX mapping shows the deposited copper in the pores of APA