Modified approximation and error estimation for King’s type(p,q)-BBH operators

In this paper,the King’s type modification of(p,q)-Bleimann-Butzer and Hahn operators is defined.Some results based on Korovkin’s approximation theorem for these new operators are studied.With the help of modulus of continuity and the Lipschitz type maximal functions,the rate of convergence for these new operators are obtained.It is shown that the King’s type modification have better rate of convergence,flexibility than classical(p,q)-BBH operators on some subintervals.Further,for comparisons of the operators,we presented some graphical examples and the error estimation in the form of tables through MATLAB(R2015a)

Effect of background electrolytes on the adsorption of nitroaromatic compounds onto bentonite

To further elucidate interaction of nitroaromatic compounds with mineral surface, the sorption of m-dinitrobenzene （m-DNB） and nitrobenzene to original bentonite in aqueous solution containing different electrolytes （i.e., KCl, NH4Cl, CaCl2 and Tetramethylammonium bromide （TMAB）） was studied. The sorption of m-DNB was greatly enhanced with the presence of KCl and NH4Cl, while little influence was observed with CaCl2 and TMAB, following the order of KCl 〉 NH4Cl 〉〉 TMAB, CaCl2, or DI water. For nitrobenzene, sorption enhancement only occurred at high nitrobenzene concentrations in the presence of KCl, and the solute equilibrium concentration at inflexion point was lowered with increasing KCl concentration. These sorption enhancements were significantly promoted with the increase of electrolyte concentration. The salting-out effect is insufficient to account for the sorption enhancement by original bentonite with increasing KCI or NH4Cl concentration. X-ray diffraction patterns of bentonite suspensions indicated that the sorption enhancement of m-DNB was attributed to the intercalation of K^＋ or NH4^＋ into bentonite interlayer and then dehydration with m-DNB to form inner-sphere complexes, which caused previously expanded bentonite interlayers to collapse in aqueous suspension, thus further enhanced the interaction of phenyl with siloxane surface. In comparison, the sorption enhancement of NB is attributed to the formation of outer-sphere complexes with K^＋ at high solute-loadings （〉 20（0-400 mg/kg）. The sorption of m-DNB to initially modified TMA^＋-bentonite and K^＋-bentonite was almost the same as respective sorption to original bentonite in solution containing TMA^＋ and K^＋.