Removal of Multi-active-blue Dye from Aqueous Phase using Magnetic Poly-pyrrole Nano-composites: Fixed-bed Adsorption Studies

摘要

The aim of this study was to explore the use of adsorption in the removal of synthetic dyes in water bodies. These dyes pose a serious threat to both aquatic and human lives because of their toxicity and persistence in the environment. There is therefore an urgent need to remove them from water before discharge to the environment. Many of the current dye treatment methods are generally inefficient and expensive; however, adsorption is the most preferred method due to its inherent benefits such as simplicity, ease of operation, low cost and insensitivity to toxic environments. The study evaluated the removal of Multi-Active-Blue (MAB) dye from aqueous solution using poly-pyrrole-magnetitenano-composite (PPy/Fe_3O_4) adsorbent in a fixed-bed adsorption column. The influences of initial MAB dye concentration, bed mass and flow rate at the influent stream on the adsorption performance were investigated in an up-flow fashion. Results showed that early breakthrough time (t_b) was attained at high solution flow rates and dye concentrations and low bed mass. Increasing concentration from 50 to 150mg/L resulted in a decrease in t_b from 610 to 110 min. Furthermore, at the studied conditions, the highest breakthrough time obtained was 690 min at which 228 bed volumes were processed at 1.45g/L Adsorbent Exhaustion Rate (AER).The adsorber design parameters were calculated by fitting the experimental data to the column adsorption models and based on analysis of linear regression coefficients (R~2), it was established that the MAB dye adsorption was described best by Yoon-Nelson model throughout the entire breakthrough profile, while Bohart-Adams model fitted only the initial portion of the profiles. Accordingly, it was concluded that PPy-Fe_3O_4nano-composite material is a promising adsorbent for cleaning textile dye polluted water.