Kinetics and thermodynamics of lead (II) adsorption on lateritic nickel ores of Indian origin

Adsorption kinetics of Cr(VI) ions from aqueous solutions onto black rice husk ash

“…The positive value of ΔH ≠ denotes that the formation of the activated complex is an endothermic process. The negative value of ΔS ≠ suggests that Cr(VI) adsorption onto BRHA is an associative mechanism [28]. Using Eq.…”

“…The value of ΔH ≠ determines whether the nature on the formation of the activated complex from the reagent is endothermic or exothermic. The magnitude and sign of ΔS ≠ gives an indication whether the adsorption reaction is an associative or dissociative mechanism [28]. Taking logarithm from both sides of the equation and rearranging we obtain the next linear equation [27]:…”

Application of dolochar in the removal of cadmium and hexavalent chromium ions from aqueous solutions

“…The adsorption capacity of dolochar for both Cd(II) and Cr(VI) was compared with the reported values [35][36][37][38][39][40][41] for waste materials and shown in Table 8. From the results, it is evident that dolochar is comparable to many adsorbents for treating wastewater containing Cd(II) and Cr(VI) metal ions.…”

Studies on removal of lead ions from aqueous solutions using iron ore slimes as adsorbent

“…Iron ore slime with high amount of goethite has a high potential as adsorbent for heavy metal ions [19]. Few researchers have experimented on certain types of iron bearing materials and found to be effective in metal ion removal [20,21] without going deep into the proper characterization of the used material. In the present study, detailed characterization studies of iron ore slime and the effect of various adsorption parameters such as time of agitation, adsorbent dose, pH and temperature have been studied on the removal of lead ions from aqueous solutions.…”