الفهرس 
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Abstract
The environmental pollution with industrial wastewater pollutants, especially heavy metals, is one of the most prominent problems in the world, especially Egypt. These metals have the ability to change the functions of important biological molecules such as protein, enzymes and amino acid, which leads to serious diseases in animal and human himself.
The field study was conducted in three Egyptian governorates (El-Sharkia, El-Menofia and El-Fayium) by collecting samples of fish, soil, vegetables, and industrial wastewater from three sites of each governorate to study the concentration of lead, copper, cadmium, iron and zinc.
In the present study the concentrations of 5 heavy metals (Pb, Cu, Cd, Fe and Zn) in the collected wastewater samples were studied and indicated that the highest mean concentration of Fe and Zn (6.24 mg/L and 3.21 mg/L respectively), were observed in F1site: Koum Oshim industrial region in El-Fayium governorate, while, the greatest mean concentration of Cu (9.99 mg/L) was detected in S1 site (Abbasa drain) in El-Sharkia governorate. Moreover, the highest mean concentration of Pb and Cd (12.7 and 1.61 mg/L, respectively) was showed in M1 (Quesna industrial zone) and M2 (El- Khadrawia drain) sites respectively, in El-Menofia governorate. According to FAO and WHO, the MPL for Pb , Cd, Cu, Fe and Zn are 5 , 0.01, 2, 5, 2 mg/l respectively.
The current results of the wastewater physciochemical paramerters indicated that the TDS (total dissolved solids) values ranged between 381-1485 mg/L and the highest value was observed in M1 site in El-Menofia governorate and the highest value of the EC (electrical conductivity) was detected in the same region (2122 μs/cm). Meanwhile the pH values was in the alkaline range in the three governorates (7.1-8.4) and the greatest value (8.4) was showed in M1 site. The DO (disolved oxygyn) values were ranged between 0.2-1.4 mg/L . The acceptable limits of EC and TDS are 1000 μs/cm and 500 mg/l respectively.
In the current study, the collected fish samples were used as bio-indicator of heavy metals pollution in aquatic ecosystems. The concentration of lead, copper, cadmium, iron and zinc in the collected Nile tilapia samples was investigated. The highest mean concentration of Fe and Cu (314 and 11.2 mg/L, respectively) was detected in F1 site (Koum Oshim industrial region) in El Fayium governorate, while the greatest mean concentration of Pb (1.984 mg/L) was observed in M1 site (Quesna industrial zone) in El-Menofia governorate. The mean concentration of Cd and Zn was within MPL (30 mg/kg for Zn and 0.2 mg/kg for Cd) in the three governorates. The Maximum Permissible Limits for Pb, Cu and Fe are 0.5, 10, 146 mg/kg respectively.
Concerning to the concentration of the five metal ions in the collected soil samples, our results indicated that the highest concentration of Cd and Fe (22.10 and 3512 mg/ kg , respectively) was detected in M1site (Quesna Industrial Zone) in El-Menofia governorate, however the mean cocentration of Fe was elevated in all sites in the three governorates. Meanwhile, the mean concentration of pb was less than the MPL (100 mg/kg) in all sites in the three governorates. The greatest mean concentration of Cu was showed in F1 site (155.87 mg/kg) in El-Fayium governrate and in S1 site (81.21 mg/kg) in El-Sharkia governorate, while the mean concentration of Zn (22.33-54.12 mg/kg) was less than the MPL (200 mg/kg) in all sites in the three governorates. The MPL of CD, CU and Fe are 8, 60, and 1000 mg/kg respectively.
In the present study, the concentration of the five metals in the collected leafy vegtables (Lactuca Sativa “lettuce”, Trifolium alexandria ”clover” and Spinacia Oleracea ”spinach”) were investigated in 3 sites in the three governorates. The mean concentration of Pb in the collected vegetables samples in three governorates was ranged between 0.04-6.4 mg/kg and it was less than the MPL reported by FAO/WHO (5 mg/kg) except the clover samples collected from M2 site (El-Khadrawia drain) in El-Menofia governorate while, the mean concentration of Cd was ranged between 0.0014-0.62 mg/kg (MPL = 0.3 mg/kg) and the greater mean concentration was detected also in clover samples collected from M2 site. Also our data recorded that the mean concentrations of Zn and Cu in all sites are less than the MPL proposed by FAO/WHO (60 mg/kg of Zn and 40 mg/kg of Cu). Concerning to the mean concentration of Fe in the collected vegetables samples, present results indicated that it was not exceeded the MPL( 500 mg/kg) in most of the study sites except in F1 site (Koum Oshim region) and in F3 site (Bahr Hassan Wassef) in El-Fayium governorate (517 and 508 mg/kg, respectively).
The current study showed the evaluation of the removal effect of three heavy metals ions (Pb 2+, Cd2+ and Cu2+) from industrial wastewater by using three synthesized chitosan- based nanocomposites (ZnO@ chitosan: ZOCS, magnetite@ chitosan: MCS and hematite@ chitosan: HCS core shell).
The synthesized compounds characterized by using SEM, TEM, XRD and FTIR. The prepared chitosan showed non homogenous and non-smooth surface with straps and shrinkage. Concerning to the morphology of ZOCS, our data indicated formation of globular morphology with core and thin shell with an average size 58 nm, in addition to the Photographic studies also indicated the MCS morphology with the spherical magnetite particles which were attached on the surface of MCS NC particles with a condensed amount with particles size in the range of 8 – 40 nm (Average size 24 nm). Also, HCS images showed dumbbell-shaped crystals hematite particles aggregated to form bundles and encapsulated into the spherical dumb shaped HCS nanocomposite with particle size from 40 to 80 nm (Average size 60 nm).
In the present study, the effect of pH, initial metal ion concentration, nanocomposite dosage and equilibrium contact time were investigated. The current results showed that the maximum removal capacities of Pb2+, Cu2+ and Cd2+ was recorded at pH 6, 4 and 6.5 respectively, by using the three synthesized nanocomposites. The maximum removal percentage of Pb2+ was recorded at 90%, 96% and 93% by ZOCS and MCS and HCS NC respectively, while for Cd2+ was 74%, 86% and 79% by using ZOCS and MCS and HCS NC respectively , and the optimum removal percentage of Cu2+ was 53%, 82% and 69% by usage of ZOCS and MCS and HCS NC respectively. The current results showed that the pH was an effective parameter to the adsorption capacity where, it play a role in the surface charge of ZOCS NC, MCS NC and HCS NC and the concentration of toxic ions active sites of ZOCS, MCS and HCS.
The present study also indicated that the equilibrium contact time was a critical parameter of absorption efficiency. The equilibrium contact time of ZOCS was 30 min for Pb(II) and 60 min for Cd(II) and Cu(II), While the equilibrium time in case of MCS reached at 30 min for Pb(II) , Cd(II) and 90 min for Cu(II) . The contact time of HCS was 60 min for Pb(II)and Cu(II) and 30 min for Cd(II). Furthermore, the adsorption of toxic ions increased with increasing the contact time till reached at constant state called equilibrium time. At the beginning, fast removing is may be due to the abundant available binding sites on the surface of the adsorbent and after that, other empty surface sites were difficult to be absorbed due to repulsive forces between the adsorbate molecules.
from data of the present study, the adsorption of metal ions was adsorbent dose-dependent, an optimum adsorbent dose is essentially required to maximize the interactions between metal ions and adsorption sites of adsorbent in the solution. The effect of adsorbent dose on Pb(II), Cd(II) and Cu(II) ions adsorption was investigated for ZOCS where, it was found that Pb(II) removed at 0.1 g/l, Cd(II) and Cu(II) removed at 0.5 g/l. Concerning to MCS, it was detected that Pb(II), Cu(II)and Cd(II) removed at 0.5 g/l ,whereas, Pb(II) removed at 0.5 g/l, Cd(II)and Cu(II) removed at 0.8 g/l in case of HCS. It was found that the adsorption of metal ions increased with increasing amount of the composite but further increase in concentrations results in a decrease in removal efficiency.
In the current work, the impact of initial concentrations of metal ions on removal efficiencies was studied in the range of 10.0-160.0 mg/L. An initial concentration of 10 mg/L was associated with 91%, 73% and 52% removal efficiencies of Pb(II), Cd(II) and Cu(II), respectively for ZOCS, while 96%, 85% and 81% removal efficiencies of Pb(II), Cd(II) and Cu(II), respectively for MCS and 94%, 83% and 76% removal efficiencies for Pb(II), Cd(II) and Cu(II), respectively for HCS. It is evident that the removal efficiencies decreased with the increasing initial concentrations, where metal ions concentration was increased, while the nanocomposites active sites were not increased correspondingly so, the rate of adsorption become low by increasing initial concentration.
In the present study, the recovery capacity of metal ions from ZOCS, MCS and HCS nanocomposites was tested by restoration using 0.01M Na2EDTA and the capacities were > 97.2 % for Pb(II), > 93% for Cd(II) and > 91% for Cu(II) in case of ZOCS while, they were > 97.8% for Pb(II), > 94% for Cd(II) and > 92% for Cu(II) in case of MCS and > 98% for Pb(II), > 94% for Cd(II) and > 91% for Cu(II) in case of HCS. The recovery capacity of ZOCS, MCS and HCS nanocomposites for three ions was fully recovered with significant recovery capacity during four cycles.
The present results showed the removal rates of some metal ions (Pb2+, Cd2+ and Cu2+) from nine wastewater samples from three governorates where, samples were treated under condition of pH 5.5, 0.5 mg/L (ZOCS or MCS or HCS), shaking time 1 hr and room temperature. The removal rates of ZOCS were > 94.4% for Pb (II), > 93.2% for Cd(II) and > 88.9% for Cu(II) ; while the removal rates of MCS were > 97 % for Pb (II), > 94.9% for Cd(II) and > 89.3% for Cu(II); and in case of HCS NC, the removal rates were > 96.5% for Pb (II), > 95% for Cd(II) and > 89.5% for Cu(II) in the presence of coexisting ions Na, K and Ca and there is no significant influence on the removal efficacy.