The current work discusses the removal of brilliant dyes. These dyes were Brilliant Cresyl Blue (BCB) and Brilliant Green (BG) by the use of poly acrylic acid hydrogel beads (PAA). We examined the adsorption isotherms and found that the factors preferring it are temperature and salt, shaking effects, wet PAA, (BCB) and (BG) follows Freundlich equation more than other equations. Based on the results, there is a positive correlation between adsorption of dyes (BCB and BG) and temperature (Endothermic process). We calcauted the thermodynamic functions (ΔG, ΔS, and ΔH). The ion strength effects on the adsorptions at (20 °C) increased adsorption if the salt concentrationsis high. We treated the kinetics outcomes based on Lagergren Equation for the first-order and the second-order equations. The kinetics experimental data show that the adsorptions were the pseudo first-order change based on the changing conditions.

Biopolymer/layered silicate composites have shown unique advantages and potentials for the passive targeting of drugs because they can overcome the burst drawbacks of organic carrier, increase the drug utilization and enhance the controllable capability of drug release. Furthermore, the biocompatibility and nontoxicity of biopolymers is retained, and therefore it is promising and applicable in pharmaceutical fields. The main research aim of this work was to develop a series of biopolymer/layered silicate composite beads based on chitosan (CTS) and Laponite (LA) by a simple ionic cross-linking reaction using sodium tripolyphosphate as the cross-linker. The resultant beads were characterized by Fourier transform infrared spectroscopy, scanning electronic microscope and X-ray diffraction analysis. The swelling behaviour in physiological pH solutions (7.4 and 1.2), drug encapsulation efficiency and controlled release behaviour were also investigated by using Ofloxacin as the model drug to reveal the effects of introduced LA. The results indicate that the incorporation of LA remarkably improved the swelling behaviour, enhanced the drug entrapment efficiency, and slowed down the drug release behaviour in contrast to the pure organic CTS beads. The exfoliated LA clay could act as a physical cross-linker to facilitate the formation of network structure between the CTS and LA. It is suggested that LA may be developed as an effective additive for fabricating a sustained drug delivery system.

Hypothesis: In recent years, scientists and researchers have been looking for new and advanced materials for use in various fields, including drug delivery and biotechnology. One of the attractive  materials that has been considered in this field is chitosan-based bionanocomposite hydrogel beads. Chitosan-based bionanocomposite hydrogel beads have attracted attention as carriers in drug delivery systems due to their inherent properties such as excellent biocompatibility, high swelling, and high storage capacities.Methods: First graphene quantum dots (GQDs) were prepared by the pyrolysis method, and then their magnetic properties were obtained using iron nanoparticles (MGQD). Next they were coated with chitosan hydrogel (CS-MGQD) and finally loaded with methotrexate (MTX/CS-MGQD). This unique combination of the properties of chitosan hydrogel, the magnetic properties of graphene quantum dots, and the ability to adjust drug release has been able to create an important milestone in the field of drug delivery research and the compatibility of drugs with the biological environment. Through various analyses, including FTIR to analyze the spectra of the functional groups, XRD to identify the crystal structure, and SEM to examine the morphology of the samples, the success of the synthesis and formation of the desired compound was confirmed.Findings: The fabricated CS and CS-MGQD hydrogel beads were loaded with about 84% and 64% MTX, respectively. The results of the swelling behavior and drug release behavior showed that the hydrogel beads experience pH-dependent swelling and release of MTX. In addition, investigating the effect of MGQD concentration on swelling behavior and drug release showed that CS-MGQD has favorable stability and controllable drug release in an acid environment. Also, the Weibull kinetic model was found to be the best-fitting model for the release of MTX from CS-MGQD at pH 5. These findings suggest that the prepared magnetic bionanocomposite hydrogel beads have a good potential for pH-sensitive implantable drug delivery in the treatment of cancerous tissue.

Highly practical conditions were accomplished to prepare new ionically cross linked polymer network hydrogel beads (Caralgi) composed of polysaccharides carrageen an and sodium alginate. Disodium phosphate and the acetate derivatives of betamethasone were simultaneously loaded while the hydrogel network was being formed. A maximum loading efficiency of 91% was achieved at pH 4.8 and temperature 75 ؛C. The morphology of the Caralgi hydrogels with and without drug was investigated using SEM analysis. A more regulated morphology was observed when the drug was incorporated into the hydrogel. The in vitro release behaviour of the drug loaded Caralgi samples prepared under various conditions was also studied. The full natural system has exhibited release behaviour with no burst effect. No major difference was found in the loading and release when a highly water-soluble derivative of the drug, i.e., betamethasone disodium phosphate was used.

In this study chitosan hydrogel beads with porosity ~ 0.86 and diameter ~ 2 ± 0.07 mm were prepared from 85 % deacetylated chitosan for removal of Cd2+ ions from aqueous solutions. Chitosan powder was dissolved into dilute acetic acid as solvent and formed into spherical beads using a phase inversion technique. The effect of temperature, initial concentration of Cd2+ ions, and the period of agitation were perused to achieve the best isotherm model.Freundlich model was better fitted than Langmuir model (R2 > 0.99 and R2> 0.93 respectively, at pH of 6.3, and shaker speed of 200 rpm), the constants of Langmuir and Freundlich models were calculated, which RI. value and qmax (mg/g wet weight) at 30°C, 40°C, 50°C showed maximum uptake capacity of 61.35 (mg/g wet weight) obtained at 30°C. The calculated heat of adsorption was -8.69,-7.051, -5.513 kJ mol-1 at 30, 40, 50 °C respectively which verified an exothermic process. Kinetic studies of the adsorption phenomena were conducted in a batch system by initial concentrations from 100 to 500 mgL-1 until the equilibrium concentration Ce (mgL-1) was reached. First-order, and second-order kinetic models were used; the experimental data were in reliable compliance with second-order kinetic model with R2 value greater than 0.97. The rate constants of the kinetic models were also calculated and tabulated. To investigate the surface morphology of the chitosan beads before and after adsorption process, they were observed by the use of Scanning Electron Microscopy (SEM). The surface characterization of the beads in both cases showed metal ions binding toward the surface of porous chitosan beads. All of the experiments carried out at pH of 6.3 and agitation rate of 200 rpm, which were opted according to optimum status of previous researcher’s reports.

Removal of copper ions from aqueous solutions was carried out using a synthesized hydrogel polymeric made by sodium alginate/zeolite/chitosan. At first, a batch experiment was done to determine the diffusion coefficient. And then a column with radial feeding was designed and made. The continuous experiment was carried out with a feed by 500 ppm concentration, a flow rate of 16 cm3/min, and hydrogel beads with a radius of 1. 5 mm during the 97 min. Mass transfer and sphere diffusion equations were extracted in the bed and solved numerically. Concentration profile versus time derived from this model. To evaluate the model the results were compared by experimental data. The results show that the model has 9. 8% error. The effects of parameters including concentration (350, 500, and 700 ppm), a flow rate of 30, 16, 7. 5 mL /min, and particle radius of 1. 1. 5 and 2mm were investigated via model. The results showed that with increasing initial concentration, the lifetime of the bed was increased from 70 minutes to 76 minutes. As the flow rate increased, the filling time of the column decreased from 167 minutes to 37 minutes, and as the radius increased, the life span of the column has not sensible changes.

Dyes are a main source of pollutants in textile plant effluents. Due to their molecular structure، they are usually toxic، carcinogenous، and persistent in the environment. The aim of the present work was to explore the removal of basic blue159 (BB159) using magnetic sodium alginate hydrogel beads. Magnetic sodium alginate hydrogel beads were initially synthesized accoriodng to Rocher method using CaCl2 as a crosslink agent. Fourier transform infrared spectroscopy (FTIR) was then employed to examine the functional groups on the surface of the magnetic sodium alginate hydrogel beads. In a third stage، the magnetic properties of the beads were measured using a vibrating sample magnetometer (VSM) and the magnetic parameters were calculated. Subsequently، the effects of such parameters as adsorbent dosage، pH، initial concentration of dye، and contact time were evaluated on the BB159 removal efficiency of the adsorbent used. Finally، the Langmuir، Freundlich، Temkin، and B. E. T models were exploited to study the adsorption isotherm of BB159 onto the magnetic sodium alginate hydrogel beads. It was found that the magnetic sodium alginate beads possess both – COO and – OH groups that play important roles in the adsorption of the positively charged BB159 dye. A saturation magnetization equal to 21/8(emu/g) was obtained for the sodium alginate beads/nano Fe3O4. Results also revealed that the highest dye removal from aqueous solutions was achieved at pH=11 in 120 minutes for 9 grams of the adsorbent. The study indicated that BB159 removal using the magnetic sodium alginate hydrogel beads as the adsorbent obeys the Langmuir model. Moreover، it was shown that the efficiency of the process for BB159 removal from aqueous solutions was satisfactory (85%).

Swelling behaviour is one of the important properties of hydrogel-based drug delivery systems, which always affects the diffusion of solvent into and release of drugs from drug loaded microcapsules. In this study, the swelling behaviour of alginate-chitosan beads at acidic and basic conditions, to simulate gastric and intestinal media, were investigated. Spherical hydrogel beads were prepared by addition of aqueous sodium alginate and alginate-N,O-carboxymethyl chitosan (NOCC) solutions into CaCl2 solution. These hydrogel beads were then transferred into a chitosan solution to obtain chitosan coated beads. The effect of concentration of calcium chloride, residence time for ionic cross-linking, concentration of chitosan, addition of NOCC into alginate solution, coating of alginate-NOCC by chitosan as well as drying method on the swelling behaviour of the alginate-chitosan beads was studied. It was found that swelling degree of the air-dried and chitosan coated beads was lower than that for freeze-dried and uncoated beads, respectively. In addition, the presence of NOCC in the network resulted in reducing swelling of hydrogel beads. Swelling degree of hydrogels in basic media (pH 7.4) was also much higher than that in acidic media (pH 1.2). Thus, alginate-NOCC-chitosan beads are good candidate to be studied as colon-specific drug delivery systems.

In this study chitosan hydrogel beads with porosity ~ 0.86 and diameter ~ 2±0.07 mm were prepared from 85% deacetylated chitosan for removal of Cd2+ ions from aqueous solutions. Chitosan powder was dissolved into dilute acetic acid as solvent and formed into spherical beads using a phase inversion technique. The effect of temperature, initial concentration of Cd2+ ions, and the period of agitation were perused to achieve the best isotherm model. Kinetic studies of the adsorption phenomena were conducted in a batch system by initial concentrations from 100 to 500 mgL-1 until the equilibrium concentration Ce (mgL-1) was reached. To investigate the surface morphology of the chitosan beads before and after adsorption process, they were observed by the use of Scanning Electron Microscopy (SEM). The surface characterization of the beads .in both cases showed metal ions binding toward the surface of porous chitosan beads. All of the experiments carried out at pH of 6.3 and agitation rate of 200 rpm. Results show that wastewater treatment by Biopolymers is possible and may compete and/or replace the prevailing conventional methods.