Higher Maximum Capacity Research Articles

Performance assessment and isotherm modeling of dye uptake by h3po4 and zncl2 modified activated carbon animalis from poultry droppings

Activated carbon animalis was prepared from poultry droppings by H3PO4 and ZnCl2 activation at 5 and 15 minutes dwells time. Four different isotherms were used to model data obtained from adsorption of textile dye from waste water. Applicability of the models followed the trend; Langmuir (R2 = 0.87-0.989) > Radushkevich – Dubinin (R2=0.731-0.973)> Frendhich (R2=0.735-0.967) > Temkin (R2=0.742-0.951). The Langmuir separation factor (RL) revealed thefavorable nature of the adsorption. Samples, activated at longer time with ZnCl2 gave the best quality carbon with high saturation capacity (qD), high mean free energy (ED) and high maximum capacity (qm), but least adsorption energy (BD). Adsorption was majorly monolayer on uniform strategies, with no transmigration of adsobate. The overall results in this assessment indicate that percentage dye removal ranged between 28-63.60%, 38-76.00%, 33.58-50.40% and 24.83-76.00% for pd/A/5, pd/A/15, pd/z/5 and pd/z/15 respectively. This is an indication that, the Poultry waste biomass can be a good precursor for generating adsorbent for uptake of multicomponent organic solute.Keywords: Isotherm modeling, activated carbon, poultry dropping, textile dye

The influence of titanium on the electrochemical properties of the AB 5-type metal hydrides

AB 5-type intermetallic compounds were prepared by arc-melting in argon atmosphere. The composition of a stoichiometric compound LaNi 3.6Al 0.4Co 0.7Mn 0.3 with a hexagonal CaCu 5 structure was varied by stoichiometric and nonstoichiometric addition of Ti. With the increase of the Ti y⩽0.05 content in LaNi 3.6Al 0.4Co 0.7Mn 0.3Ti y , the hydrogen storage capacity is enhanced, whereas when y=0.1–0.3, it is decreased. The discharge capacity and cyclability are increased considerably by addition of titanium in the range of 0.02–0.1 with a maximum value at about 0.1%. The highest maximum capacity is achieved for a nonstoichiometric addition of 0.05% Ti. The kinetic properties are also additionally improved by the formation of a titanium-rich second phase. This can explain the improvement of the capacity for alloys with low Ti content. The decrease in capacity for high Ti content was also correlated with the amount of the Ti-rich phase. Therefore, the improvement of kinetics are due to the catalytic effect, grain boundary diffusion effect or more pronounced alloy pulverization upon cycling. This study has been aimed to improve the electrode properties of a series of multicomponent LaNi 3.6Al 0.4Co 0.7Mn 0.3Ti y ( y=0.0, 0.02, 0.05, 0.1, 0.2, 0.3) alloys which have mutual complementary properties. All the prepared alloys have been subjected to analyses by EDS, SEM and XRD. In order to determine the hydrogen storage capacity, the pressure composition isotherms ( P– C– T curves) have been used. The metal hydride electrodes were characterized by galvanostatic cycling test.

Chromatofocusing : III. The properties of a deae-agarose anion exchanger and its suitability for protein separations

Columns of DEAE-agarose beads of high maximum capacity (0.18 M inside the gel) were examined for their suitability for protein separation in the system of chromatofocusing. It was concluded that: (a) large sudden changes of ionic strength should be avoided; (b) when an anion exchanger is used, the component of the pre-equilibration buffer and the eluction buffer should be of the cationic type, whereas the counter ions should not be subject to association—dissociation equilibria in the pH range of operation. Furthermore slow equilibration between ion exchanger and surrounding medium caused small maxima in the pH gradient. These complications were mainly circumvented while maintaining the advantages of chromatofocusing by using the following buffer system: pre-equilibration of the column with 10 m M ammonia, pH 9.2, and elution with a linear gradient from 10 m M ammonia, pH 7.5, to 10 m M triethanolamine, pH 7.5, produced in a gradient mixer. In the approximately linear pH gradient which results a commercial preparation of myoglobin could be separated into several components. The resolution was twice as good as in previous experiments, corresponding to theoretical calcultions. However, the sluggishness of the exchanger has to be taken account when designing new ion exchangers.