الفهرس | Only 14 pages are availabe for public view |
Abstract The present thesis is divided into three chapters: Chapter (1): which include introduction and literature review of wastewater pollution by organic and inorganic compounds and their harmful effects on the environment. Hence, light is focused on Cr(VI) and methylene blue dye as two representative types of water pollutants. Also, a survey is illustrated on the feature of biosorbents use for wastewater treatment from the organic and inorganic compounds as pollutants. Chapter (2): which deal with experimental work, methods of solutions preparations and different measurements carried out during the present study. Chapter (3): which includes the results and discussion where it is divided into two parts: Part (1) preparation of magnetic – Schiff base chitosan composite from shrimp peels and its use in removal of Cr(VI) from wastewater. This type of biosorbent was prepared by the reaction of extracted chitosan from shrimp peels with ferrous, ferric ions and Schiff base, where the structure and morphology of the prepared composite were identified using FTIR, SEM and EDX. The composite was characterized by fast and higher sorption toward Cr(VI) ions from aqueous solution at abroad ranges of pH value. Significant differences were also detected on SEM and EDX analyses after Cr(VI) sorption. Its removal efficiency reached to 99.1% with Cr(VI) concentration up to 400 mg/L. The sorption isotherm was described by the Langmuir equation and the process was endothermic and spontaneous with increased randomness. The uptake kinetics was described by the pseudo-second order rate equation. The sorption capacity declined as the increase of NaCl concentration. Cr(VI) ions were efficiently desorbed from loaded sorbent with alkaline solution of 2 M of NaCl in 0.5 M NaOH. The sorbent was reused through four sorption/desorption cycles with a limited loss in efficiency less than 2.78 % at the fourth sorption cycle. Part (2) preparation of biosorbent extracted from bivalve shells for removal of methylene blue dye from wastewater. In this part, CaCO3 was extracted in the form of aragonite from bivalve shells from Port Said city shores, where the structure and morphology of the biosorbent were examined using FTIR, SEM, Zeta potential and Energy Dispersion X-ray. The surface area of CaCO3 particles was measured using methylene blue dye. The obtained results indicated that it had a removal percentage more than 93.6% with concentration up to 20 mg/L. The sorbent showed a fast kinetics for M.B sorption. The nature of interaction between the dye and the sorbent was found to be dependent upon the acidity of the medium. The adsorption isotherms were well fitted by the Langmuir equation. Uptake kinetics was correctly fitted by the pseudo-second order rate equation. The sorption reaction was spontaneous at high temperature and non-spontaneous at low temperature. The randomness of the system increased with M.B sorption. The sorbent maintained its high sorption capacity even under drastic conditions of high ionic strength. It was successfully tested for color removal form dyeing facility with efficiency reached to 95%. So, the present study recommends using of ecofriendly biosorbents extracted from shrimp peels and bivalve shells. It was proved that these two biosorbents have high removal efficiency against chromium and M.B dye, respectively. |