Table 2 - uploaded by Elavarasi S
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In the present study, the mercury removal efficiency of different agricultural waste materials sugar cane bagasse (analyzed under laboratory condition in the water. Three concentrati 0.1mg/100ml, 0.2mg/100ml and 0.3mg/100ml under pH 6 are treated with three different types of selected agricultural waste. Generally by comparing these three types of...
Citations
... The Freundlich and Langmuir models were tested. Freundlich isotherm assumed heterogeneous adsorption onto the sorbent, while Langmuir isotherm assumed homogeneous adsorption onto the surface of the biosorbent [18]. The kinetic study determines the degree of sorption. ...
This investigation has mainly focused on mercury biosorption from industrial wastewater using the tamarind flower (Tamarindus indica) as agricultural waste biosorbent. A series of experiments were performed in a batch mode to analyze the effect of process conditions such as contact time, dosage, metal ion concentration, and pH on biosorption. The characteristics of biosorbent for sorption of Hg metal ions were estimated by scanning electron microscope, BET, and pore volume analyzers. The percentage removal of mercury was obtained as 76.5% using batch experiments. The given data was validated with pseudo-first-order and second-order kinetic models and obtained R2 = 0.986 and R2 = 0.910, respectively. The results stated that data is well suited to first-order kinetics. The experimental data were also examined using Freundlich and Langmuir isotherms to identify the mechanism involved in biosorption. The values determined using Freundlich and Langmuir expressions were R2 = 0.993 and R2 = 0.974 respectively and observed best fit to Freundlich isotherm. An optimization technique such as FCCD (face-centered composite design) under response surface methodology (RSM) was employed to optimize the biosorption of mercury. The maximum rate (78.2%) of biosorption was achieved with optimized conditions of contact time 37.65 min, biomass dose 1.51gm, metal ion concentration 15.12 mg/L, and solution pH of 5 using FCCD. The thermodynamic parameters such as a change in Gibbs free energy (ΔG°) − 8612.5 J/moL, enthalpy (ΔH°) 16.36 J/moL, and entropy (ΔS°) 30.12 J/moL·K were also evaluated. The value of entropy above zero confirms the irreversibility of the biosorption process. The negative value of Gibbs’s free energy shows that the reaction is spontaneous. From the above results, it was proved that the tamarind flower is an efficient and effective biosorbent for the removal of mercury metal from wastewater.
