engleski

Adsorptive Removal of Congo Red from Synthetic and Real Wastewater Using Brewers' Spent Grain

Synthetic dyes are extensively used in many industries. However, a large portion of the dye used for dying of different materials does not remain on the material and enters the environment via industrial wastewater. The presence of dyes in bodies of water receiving the coloured industrial effluents is highly visible, even at very low concentrations and can have serious detrimental effects. Brewers’ spent grain (BSG) was previously evaluated as a low-cost adsorbent for the removal of Congo Red (CR) from the model CR solution. In this study, adsorptive removal from synthetic and real wastewater was investigated in batch adsorption experiments. The experimental conditions were as follows: initial dye concentrations of 0.01, 0.05 and 0.20 g dm-3, while all other parameters were kept constant (Vdye solution = 0.10 dm3, γadsorbent = 10 g dm- 3, 298.15 K, contact time of 300 min). The percentage of CR removal from 0.20 g dm-3 aqueous dye solution was 55.70, 93.18 and 83.53% for CR model solution, synthetic wastewater and real wastewater, respectively. The obtained adsorption data were further analysed by pseudo-first-order and pseudo-second-order kinetic models, and the results revealed that the pseudo-second-order model well described the kinetics of the adsorption process, regardless of the investigated effluent (model dye solution, synthetic and real wastewater). Since the aforementioned models cannot be used to describe the diffusion mechanism, the intraparticle diffusion model was used, and the results suggest that intraparticle diffusion was not the only process controlling the adsorption.

adsorption ; brewers’ spent grain ; Congo Red ; synthetic wastewater ; real wastewater

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