Comparative adsorption of Eriochrome black T onto recyclable steel dust wastes: Isotherm, kinetics and thermodynamic studies

In this study, low-cost steel dust wastes from two different steel-manufacturing plants were investigated for the decontamination of water containing an anionic dye, Eriochrome black T (EBT). The characterization results indicated that the steel dust particles are mesoporous material with heterogenous structure and exhibit different surface functionalities that, mainly, included metal oxides and C-O groups. The steel dust particles showed high affinity towards EBT dye (100% removal) at pH 2, and dye concentration 20 mg/L. The kinetic data was better described by pseudo-second order model indicating chemisorption interactions. The isotherm results showed good fitting to the Langmuir isotherm model implying monolayer EBT adsorption onto steel dust particles. The maximum adsorption capacity of Q-Steel and L-Steel was 100.20 mg/g and 94.18 mg/g, respectively. The thermodynamic study demonstrated endothermic nature of EBT adsorption process. The steel dust particles showed excellent removal performance of EBT dye (i.e., less than 10% reduction) after five regeneration cycles. This demonstrated that steel dust particles can be directly, used as potential low cost and recyclable adsorbent material for treating dye contaminated water streams.

Automated summary

This study investigates the use of low-cost steel dust wastes for decontamination of water containing Eriochrome black T (EBT) dye. The results show that the steel dust particles have a mesoporous structure with heterogeneous surface functionalities, including metal oxides and C-O groups. The particles exhibit high affinity towards the EBT dye and can be used for multiple regeneration cycles.