A mechanistic insight into enrofloxacin sorptive affinity of chemically activated carbon engineered from green coconut shell

The present scientific investigation deals with the sorptive expulsion of enrofloxacin molecules (ENX) through chemically activated carbon (BGCSC) developed from green coconut (Cocos nucifera) shell. Effect of six parameters viz. initial concentration of ENX (5 -30 mg L-1), pH (4-9), temperature (15 - 40 degrees C), dose of adsorbent (0.5-5.0 g m L-1), agitation speed (100 -180 rpm) and contact time (3 -30 hours) on the adsorption of ENX-onto BGCSC has been analyzed using a successive batch study. The optimum result shows 97.58 % removal of ENX with initial ENX concentration of 10 mg L-1, pH similar to 6, temperature 25 degrees C, dose of adsorbent 3 gm L-1, agitation speed 140 rpm and contact time 9 h. After the fifth cycle, the reusability capacity of chemically acti vated carbon developed from green coconut was observed to achieve to the tune of 85.76 %. The adsorbents were characterized through different instrumental analyses viz. SEM, FTIR and BET. The kinetic data of the adsorption study was best fitted into pseudo-2nd-order kinetics model. The Langmuir, Temkin and Freundlich isotherm models were studied and the experimental data were best represented by the Freundlich model. The thermodynamic study on the present sorptive removal process reveals the spontaneity and exothermic nature of the process with the negative value of Delta G degrees and Delta H respectively. The estimated cost for the production of adsorbent material was observed to be INR 294.80 indicating the cost-effectiveness of the adsorbent and its preparation methodology as well. Finally, the ENX laden BGCSC was safely disposed following the World Health Organization (WHO) guidelines.