Adsorption Phenomena in Aqueous Dye Systems

Adsorption in aqueous dye systems constitutes a critical approach for the removal of synthetic colourants from water, combining surface interactions, mass transfer and equilibrium processes. Dye molecules interact with solid adsorbents via physisorption or chemisorption, governed by surface area, pore structure, surface chemistry and operational variables such as pH, temperature, adsorbent dose and contact time. Activated carbons, biochars, nanocomposites and functionalised nanomaterials have been widely investigated, with equilibrium described by isotherm models such as Langmuir and Freundlich and kinetics by pseudo‐first‐order or pseudo‐second‐order rate equations. Recent advances focus on low‐cost and sustainable adsorbents derived from agricultural or industrial waste, as well as mechanistic insights through non‐linear modelling and continuous‐flow column studies. This research underpins the development of efficient, scalable water treatment technologies with global significance for textile effluent management and environmental protection.

Research from Nature Portfolio

Recent studies have demonstrated the viability of fixed‐bed adsorption for indigo carmine removal using activated carbon derived from Acacia nilotica sawdust. Under optimised conditions — a bed depth of 30 cm, influent dye concentration of 100 mg L⁻¹ and flow rate of 250 mL h⁻¹ — removal efficiencies reached approximately 79%, with an adsorption capacity of 24.7 mg g⁻¹. Breakthrough curves were effectively modelled using Thomas, Yoon–Nelson and bed‐depth service time approaches, revealing a balance between adsorbent usage and operational parameters. Detailed characterisation of the adsorbent’s microporosity and functional groups confirmed its suitability for continuous operation, marking a step towards industrial implementation.

Adsorption Phenomena in Aqueous Dye Systems publication trend

The graph below shows the total number of articles in adsorption phenomena in aqueous dye systems across all publications each year (not limited to Nature Index journals).

Technical terms

Adsorption isotherm: Mathematical relationship describing dye uptake at equilibrium between liquid phase and solid surface.

Kinetic model: Equation representing the rate of adsorption as a function of time and system parameters.

Breakthrough curve: Plot of effluent concentration versus time demonstrating the dynamic performance of a column.

Biochar: Carbon‐rich solid produced from biomass pyrolysis, used as an adsorbent.

Specific surface area: Total surface area of an adsorbent per unit mass, typically measured by gas adsorption techniques.

References

1. Adsorption of Indigo Carmine Dye by Acacia nilotica sawdust activated carbon in fixed bed column. Scientific Reports (2022).
2. Non-linear modelling of the adsorption of Indigo Carmine dye from wastewater onto characterized activated carbon/volcanic ash composite. Arabian Journal of Chemistry (2022).
3. Lignocellulosic-Based Materials from Bean and Pistachio Pod Wastes for Dye-Contaminated Water Treatment: Optimization and Modeling of Indigo Carmine Sorption. Polymers (2022).