Treatment Trial of Nile Tilapia (Oreochromis niloticus) Experimentally Infected with Vibrio alginolyticus Isolated from Sea bass (Dicentrarchus labrax)

BACKGROUND AND OBJECTIVE

In Egypt, Nile tilapia represents the main cultured type due to its economical price, palatability and easy culturing. This study was aimed to elucidate the pathogenicity of V. alginolyticus isolated from diseased sea bass and experimentally infected healthy Nile tilapia fish.

MATERIALS AND METHODS

Healthy Nile tilapia fish were injected I/P with V. alginolyticus isolated from diseased sea bass. Symptoms and mortality rates of infected Nile tilapia fish were recorded during the experimental period. Re-isolation of V. alginolyticus was done from infected tilapia fish by bacteriological methods. For confirmation the pathogenicity of Vibrio isolated either from marine fish or tilapia fish, PCR test was done using tdh and bla gens. Liver and kidney function tests with histopathological examinations of some organs were performed. Treatment trial was done according to the antibiotic sensitivity test.

RESULTS

The isolated Vibrio is highly pathogenic to Nile tilapia fish causing deterioration in all parameters which finished by severe mortalities. Treatment with florfenicol, enrofloxacin, or oxytetracycline reduced the mortality rate and improved liver and kidney function parameters of infected Nile tilapia fish.

CONCLUSION

V. alginolyticus can infect both marine and fresh water fish inducing a high mortality rate. Treatment of infected fish with florfenicol, enrofloxacin, or oxytetracycline reduces the mortality rate.

Adsorption of Cu2+ and Mg2+ ions on silica gel derived from rice hulls ash: Experimental and theoretical studies

Experimental study and quantum chemical calculations have been used to study the adsorption of Cu2+ and Mg2+ on silica gel derived from rice hulls ash. XRD measurements showed that the silica obtained has amorphous structure with BET of 250.1[Formula: see text]m2/g and pzc at pH 2. Adsorption of Cu2+ and Mg2+ on silica at 28[Formula: see text]∘C showed maximum capacities of 0.26 and 0.20[Formula: see text]mmol/g, respectively. In both cases of metal ions, the interaction was explained to proceed via hydrogen bonding through the outer hydration shell. Using density functional theory (DFT), interactions of hydrated metal ions with naked, mono- and di-hydrated silanol have been investigated. Calculations at the used level predict an increase of the entropy upon adsorption interaction with dehydrated silanol. Adsorption of hydrated Cu2+ and hydrated/un-hydrated Mg2+ on silanol is an exothermic process as predicted by B3LYP/6-31+G(d)//HF/6-31+G(d). This, in turn, leads to more negative free energy of reaction compared to experiment, [Formula: see text]59.8 versus [Formula: see text]25.8[Formula: see text]kJ/mol for Cu2+ and [Formula: see text]53.8 versus [Formula: see text]22.6[Formula: see text]kJ/mol for Mg2+. However, the strength of interaction between silica and both ions was reproduced correctly by theory.

Decontamination of radioactive cesium ions using ordered mesoporous monetite

We report herein the fabrication of an environmentally friendly, low-cost and efficient nanostructured mesoporous monetite plate-like mineral (CaHPO₄) as an adsorbent for removal of radioactive cesium ions from aqueous solutions. The phase and textural features of the synthesized mesoporous monetite were well characterized by XRD, FTIR, SEM, HRTEM, DLS, TGA/TDA, and N₂ adsorption/desorption techniques. The results indicate that the cesium ions were effectively adsorbed by the mesoporous monetite ion-exchanger (MMT-IEX) above pH 9.0. Different kinetic and isotherm models were applied to characterize the cesium adsorption process. The fabricated monetite exhibited a monolayer adsorption capacity up to 60.33 mg g⁻¹ at pH of 9.5. The collected data revealed the higher ability of CaHPO₄ for the removal of Cs(i) from aqueous media in an efficient way.

This study involves the identification of environmentally friendly, low-cost and efficient nanostructured mesoporous monetite plate like mineral as an adsorbent for removal of cesium from aqueous solutions.

Comparative Adsorption of Cationic and Anionic Surfactants on Fluorite

The adsorption behaviours of cetyltrimethylammonium bromide (CTAB) and dioctyl sodium sulphosuccinate (AOT) on fluorite mineral were analyzed as examples of the adsorption of cationic and anionic surfactants on salt-type minerals. Although both surfactants gave adsorption densities well below the monolayer capacity, there were considerable differences between the behaviours of the two surfactants. Thus, while the adsorption density of CTAB increased to a plateau value, that of AOT increased to a maximum before decreasing to very low values at high equilibrium concentrations of the surfactant.

Analysis of the behaviour of the surfactants was made using a modified version of the Frumkin adsorption isotherm, taking into account the cross-sectional area of the adsorbed surfactant species and the lateral interaction between their long hydrocarbon chains. The values of the free energy change indicated that both CTAB and AOT underwent adsorption via a physical process, while the lateral interaction coefficient was found to be twice as large in the case of AOT as for CTAB for small or moderate coverage. This latter behaviour was attributed to the fact that while CTAB possesses only one hydrocarbon chain per molecule, AOT has two such chains.

The Adsorption of Sulphonate on Fluorite Single Crystals as Examined by in-situ FT-IR Internal Reflectance Spectroscopy

The adsorption densities of dioctyl sodium sulphosuccinate (AOT) at the surface of a fluorite single crystal were calculated from in situ FT-IR internal reflection spectroscopic data. The results were analyzed according to the modified Frumkin isotherm in order to evaluate the lateral interaction coefficient, a, and the adsorption free energy change, ΔGθ0. The adsorption kinetics of AOT at a fluorite internal reflection element (IRE) were studied. In addition, by monitoring the –CH2 adsorption band using polarized light, it was possible to investigate the orientation of the adsorbed species on the fluorite IRE surface.

Cysteine-Functionalized Chitosan Magnetic Nano-Based Particles for the Recovery of Light and Heavy Rare Earth Metals: Uptake Kinetics and Sorption Isotherms

Cysteine-functionalized chitosan magnetic nano-based particles were synthesized for the sorption of light and heavy rare earth (RE) metal ions (La(III), Nd(III) and Yb(III)). The structural, surface, and magnetic properties of nano-sized sorbent were investigated by elemental analysis, FTIR, XRD, TEM and VSM (vibrating sample magnetometry). Experimental data show that the pseudo second-order rate equation fits the kinetic profiles well, while sorption isotherms are described by the Langmuir model. Thermodynamic constants (ΔG°, ΔH°) demonstrate the spontaneous and endothermic nature of sorption. Yb(III) (heavy RE) was selectively sorbed while light RE metal ions La(III) and Nd(III) were concentrated/enriched in the solution. Cationic species RE(III) in aqueous solution can be adsorbed by the combination of chelating and anion-exchange mechanisms. The sorbent can be efficiently regenerated using acidified thiourea.

Fast removal of uranium from aqueous solutions using tetraethylenepentamine modified magnetic chitosan resin

Chitosan was cross-linked using glutaraldehyde in the presence of magnetite. The resin was chemically modified through the reaction with tetraethylenepentamine (TEPA) to produce amine bearing chitosan. The resin showed a higher affinity towards the uptake of UO2(2+) ions from aqueous medium: maximum sorption capacity reached 1.8 mmol g(-1) at pH 4 and 25 °C. The nature of interaction of UO2(2+) ions with the resin was identified. Kinetics were carried out at different temperatures and thermodynamic parameters were evaluated. Breakthrough curves for the removal of UO2(2+) were studied at different flow rates, bed heights and after 3 regeneration cycles. Hydrochloric acid (0.5 M) was used for desorbing UO2(2+) from loaded resin: desorption yield as high as 98% was obtained.

Fast kinetic and efficient removal of As(V) from aqueous solution using anion exchange resins

Glycidyl methacrylate/methelenebisacrylamide resin with immobilized tetraethylenepentamine ligand was prepared. This pentamine containing resin was transformed to two anion exchange resins through treatment by glycidyl trimethylammonium chloride to give (RI) or hydrochloric acid giving (RII). The resins were used to adsorb As(V) at different experimental conditions using batch and column methods. Kinetics and thermodynamic properties as well as the mechanism of interaction between As(V) and resin active sites were discussed. The maximum adsorption capacities of As(V) on RI and RII were found to be 1.83 and 1.12 mmol/g, respectively. The regeneration and the durability of the loaded resin towards the successive reuse were also investigated.

Effect of structural properties of acid dyes on their adsorption behaviour from aqueous solutions by amine modified silica

Monoamine modified silica particles (MAMS) were prepared and characterized by infrared (FT-IR) and thermogravimetric analysis (TGA). The modified silica particles were used for removal of acid orange 10 (AO-10) and acid orange 12 (AO-12) from their aqueous solutions. The adsorption behaviour of the two dyes was studied at different experimental conditions of pH, contact time, concentration of dye, temperature and salt solution. The adsorption of AO-10 followed pseudo-first order kinetics whereas AO-12 followed pseudo-second order. The two dyes showed different modes of interaction with silica surface. Desorption of the loaded dyes was carried out at pH 10 and found to be 10.4 and 91.6% for AO-12 and AO-10, respectively.

Synthesis of magnetic chelating resins functionalized with tetraethylenepentamine for adsorption of molybdate anions from aqueous solutions

Magnetic resins were synthesized through polymerization of glycidyl methacrylate (GMA) in the presence of divinylbenzene (DVB) or N,N'-methylenebisacrylamide (MBA) as hydrophobic or hydrophilic crosslinker, respectively and in presence of suspended magnetite particles. The resins containing (DVB or MBA) as crosslinker were immobilized with tetraethylenepentamine (TEP) to give the amino resins, GMA/DVB/TEP (R1-en) and GMA/MBA/TEP (R2-en), respectively. The uptake behavior of the two resins was studied towards molybdate anions and uptake capacities of 4.24 and 6.18 mmol/g [as (Mo(VI)] were obtained using (R1-en) and (R2-en). Kinetic studies showed that the adsorption followed the pseudo-second-order model pointing the influence of the textural properties of the resin on the rate of adsorption. Thermodynamic data indicated an endothermic adsorption process. The uptake of Mo(VI) and regeneration of the resins were also studied using the column method. Regeneration efficiency up to 90-96% was reached using ammonia buffer.

Selective separation of mercury(II) using magnetic chitosan resin modified with Schiff's base derived from thiourea and glutaraldehyde

Magnetic chitosan resin was chemically modified by a Schiff's base cross-linker. The interaction of the resin obtained with Hg(II) was studied and uptake value of 2.8 mmol/g was reported. The kinetic and thermodynamic parameters of the adsorption process were estimated. These data indicated that the adsorption process is exothermic and follow the pseudo-second-order kinetics. The selectivity of Hg(II) from other different metal ions in solutions using the studied resin was also reported. Breakthrough curves for the recovery of Hg(II) were studied. The critical bed height was found to be 2.05 cm. The adsorbed Hg(II) was eluted from the resin effectively using 0.1 M potassium iodide.

Synthesis of a quaternary amine anion exchange resin and study [of] its adsorption behaviour for chromate oxyanions

Glycidyl methacrylate/N,N'-methylene bis-acrylamide (GMA/MBA) was prepared and allowed to react with tetraethylenepentamine (TEP) to give glycidyl methacrylate amine resin (RPA) followed by treatment with glycidyl trimethylammonium chloride (GTA) to give glycidyl methacrylate resin bearing quaternary ammonium chloride moieties (RQA). Zeta potential measurements showed that RQA particles are positively charged over pH 2-10 indicating the strong basic nature of the quaternary amine sites. The effect of pH on the recovery of chromate by RPA and RQA was examined. The results indicated that RQA is an efficient sorbent for chromate from both acidic and basic media. The repeated use of RQA was tested through stripping the adsorbed chromate using a mixture of 0.05 NaOH and 2 M NaCl in the case of the uptake from acidic media and using 2 M NaCl solution in the case of alkaline solutions.