http://libir.tmu.edu.tw/bitstream/987654321/43034/1/4.pdf

Review of second-order models for adsorption systems.

https://dr.ntu.edu.sg/bitstream/10356/96770/1/30.%20Application%20of%20Layered%20Double%20Hydroxides%20for%20Removal%20of%20Oxyanions.pdf

Application of layered double hydroxides for removal of oxyanions: A review

Graphene oxide, particularly as magnetic particles, has recently been used as an adsorbent for wastewater treatment in applications such as heavy metals separation (mercury, cadmium, copper, chromium, arsenic) and also organics (antibiotics, dyes, i.e. Reactive black 5, etc.). Selected examples will be given in the present review – mostly from the literature. The following themes are examined among others: the synthesis route (impregnation, co-precipitation), kinetics of adsorption, thermodynamics, isotherm studies and applications in comparison with other adsorbents. c � 2013 Society of Chemical Industry

Graphene oxide and its application as an adsorbent for wastewater treatment

The adsorption of As and Se from dilute aqueous solutions, representing model power-plant effluent streams, by calcined and uncalcined layered double hydroxide (LDH) adsorbents has been investigated. The results indicate that As(V) has a greater adsorption capacity than Se(IV) for both calcined and uncalcined LDHs. An mth-order kinetic rate equation describes the adsorption kinetics of As and Se on these adsorbents. The adsorption isotherms obey the Freundlich model. The adsorption capacities of As(V) and Se(IV) on the calcined LDH are higher than those on the uncalcined LDH. The starting solution pH does not significantly influence adsorption of As and Se on calcined LDH, as long as it is higher than 4; As and Se adsorption on uncalcined LDH is, however, more sensitive to variations in the initial pH. Studies of the effect of the metal oxidation state on adsorption reveal that As(III) is more difficult to remove than As(V) by both the calcined and uncalcined LDHs. However, the adsorption of Se(IV) and Se(VI) is relatively similar on both calcined and uncalcined LDHs. Competing ions have a greater effect on Se(IV) uptake than on As(V) uptake. Desorption of As(V) and Se(IV) from the LDH depends on the type of ion species and their concentration in the desorbing solutions.

Removal of Trace Levels of Arsenic and Selenium from Aqueous Solutions by Calcined and Uncalcined Layered Double Hydroxides (LDH)

Treatment of methyl orange by calcined layered double hydroxides in aqueous solution: adsorption property and kinetic studies.

In this study, the sorptive removal of hexavalent chromium from aqueous solutions by Mg−Al−CO3 hydrotalcite was investigated in a batch mode. The influence of solution pH, conditioning duration, in...

Chromium(VI) removal from aqueous solutions by Mg-Al-CO3 hydrotalcite: Sorption-desorption kinetic and equilibrium studies

This work emphasizes the mechanical and tribological performance of Al-Si/Al2O3/MoS2 hybrid matrix composites. The composites are reinforced by varying weight percentages of Al2O3 (8%, 12%, and 16%) and MoS2 (0%, 2%, and 4%), and were prepared by stir casting. As the weight percentage of Al2O3 in a composite grows, so does its hardness and tensile strength. The addition of 2% wt. MoS2 enhances the specific strength and tribological properties, according to the research. However, when compared to other composites studied, the Al/16% Al2O3 composite had improved mechanical properties. MoS2 also aids the hybrid composite in achieving higher tribological characteristics while marginally lowering the specific strength. Taguchi orthogonal array (L27) is used to design tribological performances with process parameters viz. applied load, sliding speed and weight % of Al2O3 as well the percentage of MoS2 whereas wear rate (mm3/m), wear (µm) and coefficient of friction were considered as the responses. A hybrid Grey–Fuzzy Reasoning Approach (GFRA) is used to optimize a multi-response for avoiding vagueness in decision making. The statistical analysis revealed that Al/2%MoS2/16%Al2O3 composite has exhibited better wear resistance than other composites. The confirmation test is also conducted to validate the optimal condition obtained by ANOVA.
 

T. A. Pandi

Papers

Chromium(VI) removal from aqueous solutions by Mg-Al-CO3 hydrotalcite: Sorption-desorption kinetic and equilibrium studies

Assessment of mechanical and tribological performance of hybrid Al/MoS2/Al2O3 composite by GFRA