By manipulating the physico-chemical conditions, the adsorption characteristics study on the removal of the therapeutic drug Diclofenac on the Acid Digested Carbon of waste Leather (ADCL) were analysed. The smallest particle size affords the most surface area and more adsorbed material (92.43% for 0-63 micron). The adsorption of diclofenac on this acid-digested carbon of waste leather required acidic pH ranges. Nevertheless, different adsorbates preferred various acidic pH ranges between 1 and 6. In this instance, 92.15% of adsorption occurs at pH 5. The results of this study revealed that the percentage of diclofenac adsorption is directly proportional to the dosage and contact time of the adsorbent and inversely proportional to the initial concentration of the adsorbate. Due to the absence of a chemical bond forming between the adsorbent and adsorbate, the order of this adsorption is pseudo-second order kinetics, and therefore falls under the category of physisorption. For these experiments, the fruendlich and Langmuir isotherm model is appropriate. The thermodynamic analysis shows negative ∆Go and positive ∆Ho and ∆So values, indicating that this adsorption is, respectively, spontaneous, practicable, and physical in character. The FT-IR, SEM, and XRD spectrum data support the above experimental findings.

The adsorption characteristics study on the removal of therapeutic drug naproxen on the acid digested carbon of waste leather were analysed by varying the physico-chemical conditions. Effect of particle size, adsorbent dosage, pH, temperature, initial concentration of adsorbate and contact time were analysed carefully by batch mode. The minimum particle size gives maximum number of surface area and adsorbed more, 90.89% for 0-63 micron. Acidic pH ranges were desirable for the adsorption of naproxen on this Acid digested carbon of waste Leather (ADCL). But different adsorbates preferred different acidic pH ranges of pH from 1 – 6. Above pH 6 precipitations of drugs takes place. In this case at pH 1, 96.87% of adsorption takes place. The percentage of adsorption of naproxen is directly proportional to the adsorbent dosage and contact time and inversely proportional to the initial concentration of the adsorbate were found out from this study. Order of this adsorption is pseudo second order kinetics and it belongs to the physisorption, because of no chemical bond formation between the adsorbent and adsorbate. The fruendlich and Langmuir isotherm model is fit for these studies. The thermodynamic study reveals the negative ∆Go, positive ∆Ho and ∆So values concluded that this adsorption is spontaneous, feasible and physical in nature respectively. The spectral evidence from the FT-IR, SEM and XRD are in favour of above experimental results.

To study the adsorption of Rhodamine-B dye (Rh-B) from artificial aquatic solution by using activated Hygrophila auriculata nano carbon under batch adsorption mode. Activated nano carbon was synthesized from Hygrophila auriculata and it was characterised by analytical methods such as BET(BJH), XRD, FTIR, and SEM with EDX. The equilibrium adsorption data were calculated and it was interrelated using Freundlich, Langmuir, Temkin, Hurkins-Jura, Halsay, Radlich-Peterson, Dubinin-Radushkevich, Jovanovic, and Brunauer Emmett Teller (BET) isotherm models. The kinetics of the adsorption technique was examined via pseudo- second order, Elovich mode and intraparticle diffusion methods. Thermodynamic parameters like change of free energy (ΔG°), change of enthalpy (ΔH°), and change of entropy (ΔS°) has been estimated. The value of regression coefficient (R2) indicates that Langmuir isotherm suitable to designate the process. The maximum adsorption capacity of monolayer is 204.11mg/g at 40°C. Based on the R2 value the adsorption mechanism was fitting to the pseudo-second order model. Thermodynamic factors obtained (ΔG° ranged from -4429.50 to -640.26 kJ/mol; ΔH° ranged from 5.38 to 12.84 kJ/mol; and ΔS° ranged from 19.82 to 50.23 J/K/mol, correspondingly) representing the Rh-B dye removal from artificial aquatic solutions by AHANC is there spontaneous, endothermic and possible in nature respectively. The outcomes point out that AHANC could be used as low-price and an effective adsorbent for the removal of Rh-B dye from artificial aqueous solution.