Related Experiment Video
Updated: Feb 15, 2026

Study of Short Peptide Adsorption on Solution Dispersed Inorganic Nanoparticles Using Depletion Method
Published on: April 11, 2020
Direct red 81 adsorption on iron filings from aqueous solutions; kinetic and isotherm studies
Mansooreh Dehghani1, Majid Nozari1, Atefeh Fakhraei Fard1
1a Research Center for Health Sciences, Department of Environmental Health, School of Health , Shiraz University of Medical Sciences , Shiraz , Iran.
Abstract:
Direct Red 81 (DR-81) dye with a very high water solubility is widely used in many industries particularly textile industries. This study aimed to evaluate the practicability of using iron filings for the adsorption of DR-81 dye from the aqueous solutions. The effects of pH, adsorbent dose, initial DR-81 dye concentration, and adsorption time on adsorption process were also evaluated. The maximum of adsorption efficiency of DR-81 dye achieved in the optimum pH: 3, adsorbent dose: 2.5 g/L, contact time: 30 min, and initial dye concentration: 50 mg/L. The dye adsorption efficiency is increased by increasing the adsorbent dose and adsorption time. The kinetic and isotherm studies indicated that the adsorption process obeys a pseudo-first-order and Langmuir isotherm models. The experimental studies indicated that iron filings had the potential to act as an alternative adsorbent to remove the DR-81 dye from an aqueous solution.
Related Concept Videos
Chemical Reactions in Aqueous Solutions
Aqueous Solutions and Heats of Hydration
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
Leveling Effect and Non-Aqueous Acid-Base Solutions
The Leveling Effect of a Solvent
A generic acid (HA) reacts with the generic base (B-) to yield the corresponding conjugate base (A-) and conjugate acid (HB):
General Properties of Solutions
Solution Formation
This selective...
Isothermal Processes
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...

