Removal of Cationic and Anionic Dyes from Single and Binary Dye Systems with Persian Charred Dolomite using First-Order Derivative Spectrophotometer Analysis Method
This research was conducted to study the feasibility of removing cationic and anionic dyes from single- and binary-component systems by a local natural adsorbent of Persian dolomite (treated at about 800 °C). In single system, batch experiments were carried out to examine the effect of contact time, initial dye concentration, temperature, stirring speed and adsorbent dose on the adsorption of dyes. Studies showed that cationic dye was not noticeably adsorbed by charred dolomite; however, charred dolomite has the potential to act as an efficient adsorbent for the removal of the reactive dye from groundwater solution with maximum adsorption capacity of 7.3 mg/g. Rate of dye removal was greatly increased with increasing temperature. Thermodynamic studies showed that the adsorption of RR195 on charred dolomite is spontaneous and endothermic. First-order derivative spectrophotometer analysis was used as a method for dye analysis in binary dye system. Study on the effect of two components in binary dye mixture on the adsorption capacity of charred dolomite demonstrated that while RR195 enhanced the uptake of the cationic dye (synergism), BV16 showed nearly non-interaction effect on the anionic dye removal. In both single and binary dye systems, equilibrium and kinetic data showed that the adsorption process satisfactorily fitted to Langmuir equation and pseudo second order kinetics respectively.
Keywords - Dye adsorption, Charred dolomite, Derivative spectrophotometer, binary dye system