The use of cheap and eco friendly adsorbents prepared from freely and abundantly available Acacia nilotica leaves have been investigated by batch methods. Microwave treated A. nilotica leaves (MVM) are more effective than chemically treated A. nilotica leaves (CVM) for the removal of rhodamine B (RH B) from aqueous solution. The effect of initial pH, contact time and initial dye concentration of RH B onto CVM and MVM has been investigated. The applicability of the linear form of Langmuir model to CVM and MVM was proved by the high correlation coefficients R 2 = 0.9413 and 0.9681 for RH B adsorption. The R 2 values were greater than 0.994 for all RH B concentrations, which indicates the applicability of the pseudo-second-order kinetic model. The recycling ability of MVM is greater than CVM. The preparation of MVM does not require an additional chemical treatment step and it attains rapid equilibrium. Hence it is agreeing with the principles of green chemistry and less time is required to possess high adsorption of RH B. Therefore, the eco friendly adsorbent MVM is expected to be environmentally and economically feasible for the removal of RH B from aqueous solutions.

In this article, the agricultural solid waste, Cucumis sativus (RCS) was activated by sulfuric acid (CCS) for removing typical basic dyes, crystal violet (CV) and rhodamine B (RHB) from aqueous solution. The different parameters like effect of concentration, sorbent dosage, contact time and pH were studied. Isotherm data showed that the Langmuir isotherm provided the best correlation for the adsorption of CV and RHB onto RCS and CCS. The kinetic experimental data were well fitted by the pseudo-second-order kinetic model with intraparticle diffusion being one of the rate limiting steps. It can be concluded that C. sativus, the eco friendly adsorbent, is expected to be environmentally and economically feasible for the removal of CV and RHB from aqueous solution.

No abstract

The present paper aims to investigate the physical characteristics ofAcacia niloticaleaves (MVM) relative to their use as an adsorbent for removal of hazardous Cr (VI) from waste water. The adsorbent was characterized by FTIR and SEM studies. The applicability of the Langmuir model to MVM was proved by the high coefficient of determination. Eight error analysis methods, namely, residual root mean square error (RMSE), chi-square (χ2), sum of the square of the errors (ERRSQ), composite functional error (HYBRD), derivative of Marquardt's percent standard deviation (MPSD), average relative error (ARE), sum of absolute error (EABS), and average percentage error (APE) were used to evaluate the suitability of the adsorption isotherm. Desorption reveals that recovery of the metal from adsorbent was possible. The ecofriendly adsorbent MVM is expected to be an environmentally and economically feasible adsorbent for the removal of Cr (VI) from aqueous solution and real waste water.