الفهرس 
Chapter 1 : IntrodutionOnly 14 pages are availabe for public view
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Abstract
The existence of surface groups on carbon materials is the primary determinant of the electrochemical interface state and characteristics of carbon surfaces, including isoelectric point, stability, ion adsorption, contact resistance, and self-discharge. It is anticipated that the presence of functional heteroatom groups on the surface of carbon materials will increase both their ability to adsorb ions and their hydrophilicity/lipophilicity. As a result, it is thought that altering the surface characteristics of carbon-based materials is an effective way to increase their ability to absorb substances. Numerous methods of nitrogen doping in carbon matrixes exist. In this work, Nitrogen doping activated carbons (NDACs) were prepared by many ways: fish waste (mixture of Atherina hepseetus and Sardina Pilchardus of 60% protein), saw dust, ZnCl2 and urea at high temperature (600, 700, and 800 °C) under a flow of ammonia or nitrogen gases. Utilizing FTIR, TGA, DTA, BET, BJH, MP, t-plot, SEM, EDAX, and XRD, the produced NDACs were examined. Hexavalent chromium and organic dyes like Acid brown 14 and Acid yellow 36 adsorption processes were studied using various isotherm and kinetic models.
In order to test for Acid Brown 14 (AB14) dye adsorption from aqueous solution, nitrogen doped activated carbon (NDAC1) was made from saw dust/zinc chloride (2:1) by heating under flow of ammonia gas at 600, 700, and 800 °C. The prepared activated carbon’s nitrogen mass percentage ranged from 17.99 to 21.43%. Specific surface area, monolayer volume, and mesoporous mean pore diameter for the NDAC1 produced at 600 °C were 281.84 m2/g, 64.753 cm3/g, and 2.352 nm, respectively. The NDAC1 produced at 600 °C and containing 21.12% nitrogen was determined to be the most effective at removing the AB14 dye from water and was given the designation NDAC1-600. We examined the effects of solution pH, starting concentration, and adsorption dose on the AB14 dye adsorption by NDAC1-600. It was discovered that the removal effectiveness of AB14 dye by NDAC1-600 was pH dependent, with the best elimination occurring at pH 1.5. The electrostatic interaction between the positively charged NDAC1-600 sites and the anionic AB14 dye is responsible for the adsorption of the AB14 dye. Both Temkin and pseudo second order (PSO) adsorption kinetic models were used to precisely identify the AB14 dye adsorption. Additionally, the adsorption procedure was monolayer sorption of AB14 dye on NDAC1-600, and the highest adsorption capacity (Qm) was 909.09 mg/g. For the removal of the AB14 dye from water, NDAC1-600 had proven to be a reliable, accessible, and environmentally friendly adsorbent. It may also be used to remove other dangerous contaminants.
Moreover, the formation of self-nitrogen doped activated carbon (NDAC2) by a novel way of employing fish meal (mixture of Atherina hepseetus and Sardina pilchardus of 60% protein) as nitrogen dopant, ZnCl2 as impregnate agent, sawdust as carbon source and water with a mass ratio (2:1:1:12), which subjected to hydrothermal process was also fabricated. The hydrothermal mixture obtained was oven dried and carbonized under flow of nitrogen for 1 h at 600, 700, and 800 °C. The characterization of NDAC2 were performed by the FT-IR spectroscopy, TGA, DTA, surface area analysis (BET, BJH, MP, t-plot), SEM, EDAX, and XRD analyses. The synthesized NDAC2 exhibited unique features such as microporous structure (1.84” " ~ " ”2.01 nm), high surface area (437.51” " ~ " ”680.86 m2/g), volume of total pores (0.22” " ~ " ”0.32 cm3/g) and nitrogen content (12.82” " ~ " ”13.73%). Batch removal tests were achieved to investigate the impact of chromium ions starting concentration (100-400 mg/L), NDAC2-600 dose (0.5-2.5g/L), pH and time of contact (5-120 min). Such helpful characteristics of NDAC2 particularly for NDAC2-600 were suitable to use as an excellent adsorbent for Cr6+ ions with a maximum adsorption capacity (Qm) (769.23 mg/g), and the highest chromium ions adsorption uptake (81.18%) was obtained at pH value 1.5 at room temperature. Both Halsey and Temkin models fitted the adsorption data quite reasonably. The uptake of toxic chromium ions is best represented with pseudo-second-order rate kinetics data.
The fabrication of self-N-doped porous activated carbon (NDAC3) was completed by combining fish waste (with a 60% protein content), which was thought to be a self-nitrogen dopant. In a mass ratio of 5:5:5:1, zinc chloride, urea, sawdust, and fish waste were subjected to hydrothermal treatment at 180 °C for five hours, followed by one hour of pyrolysis under a N2 stream at 600, 700, and 800 °C. AY36 dye recovery from water using the synthetic NDAC3-800 was approved utilizing batch tests. With the use of FTIR, TGA, DTA, BET, BJH, MP, t-plot, SEM, EDAX, and XRD, the synthesized NDAC3 was examined and evaluated. The results showed the successful formation of NDAC3-600, NDAC3-700 and NDAC3-800 with nitrogen mass percentage content (4.21, 8.13 and 9.85 %, respectively). The NDAC produced at 800 °C, designated NDAC3-800, and has the highest nitrogen concentration (9.85%). The specific surface area, monolayer volume, and mean pore diameter of the NDAC3-800 were 727.34 m2/g, 167.11 cm3/g, and 1.97 nm, respectively. The NDAC3-800 indicated the highest percentage of removal when the manufactured NDAC3 was tested to remove AY36 dye. As a result, it is decided to experiment with the AY36 dye removal from water by changing the pH of the solution, the starting dye concentration, the dosage of NDAC3-800, and the period of contact. The optimal pH value of 1.5 provided 85.86% removal efficiency and 232.56 mg/g maximum adsorption capacity (Qm) for the removal of AY36 dye by NDAC3-800. The equilibrium data fit well with the LIM and TIM, whereas the kinetic data had the best fit model with the PSOM. The electrostatic interaction between the AY36 dye and the accessible charged sites on the NDAC3-800 surface can be attributed to the mechanism of AY36 dye adsorption. For the removal of the AY36 dye from water, the NDAC3-800 can be used as an effective, readily accessible, and environmentally safe adsorbent.