Quality assessment of drinking water of Multan city, Pakistan in context with Arsenic and Fluoride and use of Iron nanoparticle doped kitchen waste charcoal as a potential adsorbent for their combined removal

In majority cities of Pakistan, ground water is the main source of drinking water supply in the taps. Studies from different areas of Pakistan reported the presence of arsenic (As3/5+) and fluoride (F−) in drinking water supplies and can be envisaged as a deep-rooted cause of daily exposure of these in humans. The present study was planned with three way approach, i.e., to assess drinking water quality in Multan city, a highly populated and industrial activity area; synthesis of nano-adsorbent for simultaneous, effective and low-cost removal of fluoride and arsenic and manage waste by utilization of kitchen waste for synthesis of the nano-adsorbent. Out of 30 samples collected, 80% and 73% samples were found exceeding maximum residual limits (MRL) for F− and As3/5+, respectively, while 53% samples had both As3/5+ and F− concentrations greater than MRL. All these water samples were then treated with prepared nano-adsorbent, i.e., iron nanoparticles doped kitchen waste charcoal after evaluating the optimized experimental parameters and application of adsorption, kinetics and thermodynamic models. The nano-adsorbent showed high removal efficacy 81–100% for F− and 13–100% for As3+.

Study of Effect of Size on Iron Nanoparticle by Molecular Dynamics Simulation

We use the molecular dynamics simulation to study iron nanoparticles (NPs) consisting of 4000, 5000, 6000 atoms at temperatures of 300 and 900 K. The crystallization and microstructure were analyzed through the pair radial distribution function (PRDF), the potential energy per atom, the distribution of atom types and dynamical local structure parameters <fx>, where x is the bcc, ico or 14. The simulation indicated that amorphous NP contains a large number of ico-type atoms that play a role in preventing the crystallization. Amorphous NP is crystallized through transformations of f14 > 0 and fbcc = 0 type to bcc-type atoms when it is annealed at 900 K upon 40 ns. The growth of crystal clusters happens parallel with changing its microstructure. The behavior of the crystal cluster resembles the nucleation process described by classical nucleation theory. Furthermore, we found that the amorphous NP has two parts: the core has the structure similar to the one of amorphous bulk, in while the surface structure is more porous amorphous. Unlike amorphous NP, the crystalline NP also has three parts: the core is the bcc, the next part the distorted bcc and the surface is amorphous. Amorphous and crystalline NPs have part core which has the structure not depend on size. Doi: 10.28991/HIJ-2021-02-03-01 Full Text: PDF