Effective separation of toxic azo dyes from water system using the activated carbon derived from Prosopis juliflora roots

An experimental investigation of azo dye removal using activated Prosopis juliflora root was carried out using the batch adsorption technique. The P. juliflora roots were collected and synthesized using a chemical synthesis technique, and their pore size and surface area was analyzed using N2 – adsorption and desorption process. The scanning electron microscopy/energy-dispersive X-ray spectroscopy analysis confirms the presence of targeted azo dyes on the surface of the prepared adsorbent material and the thermal stability of the adsorbent was analyzed using thermogravimetric analysis and derivative thermogravimetry. The X-ray diffraction analysis shows the amorphous structure and the intensity of activated charcoal P. juliflora adsorbent. Batch adsorption studies were conducted to determine the optimal adsorption parameters such as pH, dosage level, concentrations, contact time, and temperature. Adsorption kinetic studies confirm the favorable adsorption process between the adsorbate and the adsorbent, and isotherm studies fitted well with the high regression values. Thermodynamic studies revealed the adsorption between the adsorbent and adsorbate to be endothermic, and the desorption studies confirmed the high recovery of spent adsorbent using concentrated sulphuric acid. As a result, the activated P. juliflora powder adsorbs 99.6% of Reactive Orange – RO-16, 94.43% of Reactive Red – RR-120, and 82.26% of Reactive Blue – RB-19 azo dyes from the prepared synthetic solutions in batch mode of adsorption process.