الفهرس 
BIOSORPTION OF INORGANIC CONTAMINANTS from WATER USING DIFFERENT TYPES OF WOODY-SAWDUST NANOPARTICLESOnly 14 pages are availabe for public view
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Abstract
A batch biosorption experiments were conducted to investigate and characterize
some chemical properties of sawdust nanoparticles (nSD) that produced from
mechanically milling and the bulk sawdust collected; to evaluate the potential of
different woody sawdust nanoparticles for phosphate biosorption capacity; study the
operating parameters including contact time, initial concentration, pH, temperature,
dosage, size, competing ion, and the possible mechanisms responsible for phosphate
removal from water by the high-sorptive biosorbent; to test the stability, regeneration
and reusability of phosphate-loaded biosorbent; and to test the phosphate removal
efficiency of the high-sorptive biosorbent on real agricultural wastewater. To achieve
these objectives, series of experiments were conducted. Bougainvillea spectabilis
(stem wood), Eucalyptus camaldulensis L. (wood-branch), and Psidium guaja L.
(wood-branch) were collected from Alexandria, Egypt during pruning processes. Bark
of the woody species was removed, and the wood was transferred to flakes or sawdust
in a sawmill in Alexandria .Stock solution of 1000 mg/L PO4
-3
or NH4
+was prepared
using KH2PO4 and NH4Cl salts. Different concentrations of phosphate/ammonium
solutions were prepared freshly prior to its use. The woody-sawdust was oven-dried at
approximately 50-60 ᵒC, and then mechanically ground by a RETSCH RMl00
electrical mortar grinder (Ball mill) to produce nanoscale sawdust particles (diminish
the particle size to <100 nm). The characteristics and element contents of all sawdust
nanoparticles were investigated using scanning electron microscopy (SEM), and
quipped with energy-dispersive X-ray spectroscopy (EDX). The surface structure of
sawdust nanoparticles (nSD) was explored with Fourier transform infrared
spectroscopy (FTIR) to illustrate the functional groups of the nanoparticle surfaces.
The specific surface area of nanoparticles was determined using the method of
Brunauer et al., (1938). All these measurements were carried out by standardized
methods that have been routinely used for nanomaterial studies. Conducting
biosorption experiments was performed by shaking 0.1 g of nSD with 10 mL (1:100
ratio) of phosphate/ammonium solutions with various concentrations (5, 10, 20, 40,
80, 160 and 320 mg/L) . The agitation was conducted at 400 rpm for 2 hours to reach
sorbate-sorbent equilibrium. At 0.5, 1, 2, 5, 10, 15, 20, 30, 40, 60, 90 and 120
minutes, aliquot was taken for phosphate/ammonium kinetics determination. Then,
centrifugation and filtration of supernatant were done. To assess quantitatively and
102
qualitatively the adsorption efficiency of the sawdust nanoparticles, the most famous
isotherm models (Langmuir, Freundlich, Temkin, Elovich, Fowler-Guggenheim,
Kiselev, and Hill-de Boer) were investigated. Moreover, the most well-known kinetic
models (power function, parabolic diffusion, first order, and Elovich) were used to
test the fitness of experimental data. Both determination coefficient (R2) and standard
error of estimate (SE) were the basis to select the best-fit model .