Analysis of non competitive and competitive adsorption behaviour of ciprofloxacin hydrochloride and ofloxacin hydrochloride from aqueous solution using oryza sativa husk ash (single and binary adsorption of antibiotics)

Among various pharmaceutical pollutants, broad spectrum antibiotics of fluoroquinolones family, emerged as major water contaminants, usually occur in the form of multicomponent mixtures in the aquatic environment. Present study pertains to the adsorption of ciprofloxacin hydrochloride and ofloxacin hydrochloride as pure component and binary mixtures under dynamic and equilibrium conditions using oryza sativa husk ash as adsorbent and characterized using XRD, FTIR and SEM analyses. Single batch adsorption was carried out to study the dependence of drug concentration, time, pH and temperature and the process was found to be dependent on all the parameters investigated, with a pH of 8 for optimum removal of both drugs at which binary adsorption of [ciplox + oflox] and [oflox + ciplox] mixture was carried out for concentration ratios 1:0, 1:0.5, 1:1, 1:1.5, 1:2 to validate the effect of presence of each on the uptake of other. Applicability of Langmuir multicomponent adsorption isotherm revealed that the affinity of each drug was depressed by the presence of other; hence the effect of the mixtures seemed to be antagonistic. Also the present study highlights the oryza sativa husk ash as a viable, cost-effective and efficient bioadsorbent for the removal of antibiotics from multicomponent mixtures, specifically for small scale industries.