► The reactor used in the study was a rotating cylinder packed with cation exchange resin. ► The experimental data were analyzed using different isotherms. ► The equilibrium data fit well in the ...Langmuir isotherm. ► The experimental data were analyzed using four sorption kinetic models. ► Results show that the Elovich equation provides the best correlation for the biosorption process.
The present study is concerned with the mass transfer and kinetics study of zinc ions removal from aqueous solution using a cation exchange resin packed in a rotating cylindrical basket reactor. The effect of various experimental parameters on the rate of zinc ion removal, such as initial zinc ion concentration, packed bed rotation speed and temperature has been investigated. In addition to find a suitable equilibrium isotherm and kinetic model for the zinc ion removal in a batch reactor. The experimental isotherm data were analyzed using the Langmuir, Freundlich and D–R equations. The equilibrium data fit well in the Langmuir isotherm. The experimental data were analyzed using four sorption kinetic models, pseudo-first and second-order equations, the Elovich and the intraparticle diffusion model equation, to determine the best fit equation for the biosorption of zinc ions onto purolite C-100 MH resin. Results show that the Elovich equation provides the best correlation for the biosorption process.
In this study, a novel continuous flow-circulation photocatalytic reactor was acquired for treatment of synthetic wastewater containing a binary mixture of ammonia and phenol. Performance of the ...photo-reactor was examined using synthesized N-Doped ZnO Beads (N-ZnB) within the existence of Hydrogen peroxide (H2O2) and UV irradiation. The Beads of catalyst were synthesized using modified sol–gel method. A protocol was followed for the characterization of N-ZnB catalyst by performing some common analytical methods such as SEM, EDS, Raman and DRS. N-Doping narrows in band gap energy as calculated from DRS the band gab energy reduced from 3.2 eV to 3.16 eV and reduces electron – hole pair recombination and accordingly improves the efficiency of ammonia and phenol photo-degradation. The optimum photo-degradation conditions were detected by examining the effect of operational parameters as the flow rate, pH, catalyst dosage, H2O2 concentration and initial concentration for both ammonia and phenol. At optimum conditions, N-ZnB catalyst achieved 98.3% and 95.8% degradation for both ammonia and phenol, respectively, after 2 hr of UV irradiation. Also, the reusing ability and strength of N-ZnB was investigated. The developed beads could be used as an effective catalyst for the degradation of binary mixture of ammonia and phenol from wastewater.
In this study, two activated carbons were prepared from loofa, loofa carbon-1 (LC1) and loofa carbon-2 (LC2). The surface structure of LC1 and LC2 were analyzed by scanning electronic microscopy ...(SEM). The ability of LC1 and LC2 to remove reactive orange (RO) dye from aqueous solutions by adsorption has been studied. A series of experiments were conducted to assess the effect of system variables such as initial pH, initial metal ion concentration and temperature. The results showed that the adsorption of dye was maximal at the lowest value of pH (pH =1) and the most suitable sorption temperature was 25°C with maximum capacities of 38.3 and 50 mg/g for LC1 and LC2 respectively. Langmuir, Freundlich, Dubinin–Radushkevich (D–R), Temkin and Harkins–Jura isotherms were used to analyze the equilibrium data at different temperatures. The adsorption kinetics was found to follow a pseudo-first-order rate kinetic model. In addition, various thermodynamic parameters, such as standard Gibbs free energy (▵
G
0), standard enthalpy (▵
H
0), standard entropy (▵
S
0), and activation energy (
E
a) have been calculated. The sorption process of reactive orange (RO) dye onto different activated carbons prepared from loofa was found to be spontaneous and exothermic process.
Biosorption of colours is an important technology for treatment of different types of industrial wastewaters containing dyes. The objective of this study was to convert green alga Ulva lactuca to dye ...adsorbents for wastewater treatment. The importance of commonly available green alga Ulva lactuca was investigated as viable biomaterials for the biological treatment of synthetic basic blue 9 (5-ch1oro-N,N,N
′
,N
′
-tetramethyl-5λ
4
-phenothiazine-3,7-diamine) effluents. The results obtained from the batch experiments revealed the ability of the green algae to remove the basic blue 9, and this was dependent on the dye concentration, pH, and algal biomass. We investigated the equilibrium and kinetics of adsorption, and the Langmuir and Freundlich equations were used to fit the equilibrium isotherm. The adsorption isotherm of basic blue 9 followed both the Langmuir and Freundlich models with a correlation coefficient of ∼0.96-0.99, and the adsorption kinetics followed the pseudo-second-order model (R
2
=1.0). The maximum adsorption capacity was about 40.2 mg of dye per gram of dry green algae at pH 10, 25 g l
−1
dye and 2.5 g l
−1
alga concentrations. This study demonstrated that the green algae could be used as an effective biosorbent for the treatment of dye-containing wastewater streams.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
With over 58 million cases and 6 million deaths by August 2022, the Coronavirus disease 2019 (COVID-19), causing severe acute respiratory syndrome coronavirus 2 (SARs-CoV-2), has had an ...insurmountable impact on the world's population. This is one of the worst health crises since 1918's influenza pandemic. There are four subvariants of Omicron; BA.1, BA.1.1, BA.2 and BA.3. As a result of new mutations in its spike protein, most of which occur in its receptor binding site, the Omicron variant appears to be more transmissible and less resistant to vaccination and antibody response. Understanding Omicron's virology and mutations is essential to developing diagnostic and therapeutic methods. A thorough assessment of control measures, as well as timely adjustment of control measures, requires addressing such issues as re-infection risk, vaccine response, booster vaccine doses, and the increased rate of Omicron infections. This review article aims to look at the current information about the different types of SARs-CoV-2, focusing on the new subtype BA.2.75. Keywords: outbreak, Omicron, subvariant, BA.2.75, COVID-19
The present study is concerned with the removal of Cd (II) ions from wastewater by cementation on zinc Raschig rings placed in a rotating basket reactor. The influence of several parameters on the ...rate of cementation such as initial concentration of cadmium ions, temperature, basket rotation speeds and diameter of zinc rashing rings have been investigated. The rate of cementation was found to increase with increasing bed rotational speed and temperature. On the other hand the rate decreases with increasing the initial cadmium ions concentration in solution and the diameter of zinc Raschig rings. The activation energy was found to be 3.99 kCal/mol. The present reactor proved to be an efficient reactor for cementation reactions in view of its high area per unit volume and its high rate of mass transfer. Rates of cementation which can be expressed in terms of the rate mass transfer were correlated to the controlling parameters by the dimensionless equationSh=0.046Re0.45Sc0.33
The present mass transfer data was found to agree with the surface renewal theory.
Abstract Our aim was to evaluate the long-term outcomes of prosthetic treatment and orbital expansion in the management of microphthalmia syndromes. We did a retrospective single-centre study of all ...cases of microphthalmia treated between 1989 and 2010. The patients were divided into three groups: isolated microphthalmia, microphthalmia associated with micro-orbitism, and complex microphthalmia syndrome. To evaluate the results a score was computed for each patient by assessing the length of the palpebral fissure, the depth of the conjunctival fornix, and local complications together with an evaluation of the satisfaction of patients and their families. Forty-four children were included (27 boys and 17 girls). Twenty-seven had unilateral microphthalmia (61%) and 17 bilateral microphthalmia (39%). Twelve patients were lost to follow up. The mean duration of follow-up was 12 years (range 4–21). Management involved an ocular conformer in only 31 patients (71%). The treatment was deemed satisfactory in all except 10 children. Surgical treatment with orbital expansion permitted good symmetry of the orbital cavities with a final mean difference of 9% (range 3–17) compared with the initial 16.8% (range 13.6–20.3). The prosthetic treatment gives satisfactory results. Despite limited indications and difficult follow-up, our experience emphasises the value of surgical treatment for severe micro-orbitism.
The removal of copper and nickel ions from aqueous solutions was evaluated using an ion-exchange resin, purolite C100-MB packed in a perforated rotating basket reactor. The cation-exchange ...performance of the resin was determined by batch equilibrium method. The present reactor can replace batch agitated vessel where the resin was fluidized by rotating impeller. The effect of rotational basket speed, pH, contact time, temperature, and coexisting metal ions were demonstrated. The reusability of the resin was also studied to estimate the effectiveness of the purolite C100-MB resin. Equilibrium experimental data were successfully described by Langmuir isotherm models. An empirical design procedure based on sorption equilibrium conditions was used for predicting the size of ion exchange reactor. Experimental data were analyzed according to the surface reaction and intraparticle models. Kinetic experiments demonstrated that experimental data for purolite C100-MB resin obey pseudo-second-order models with rates limited by particle diffusion. Various thermodynamic parameters have been calculated. The sorption process of copper and nickel ions onto purolite C100-MB resin was found to be spontaneous and exothermic process.
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