Response surface methodology for strontium removal process optimization from contaminated water using zeolite...

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Strontium contamination in water poses a global environmental and health risk, particularly after nuclear incidents.
• Optimizing strontium removal processes is essential to minimize chemical usage and experimental efforts.

Purpose of the Study:

• To statistically optimize strontium removal from polluted water.
• To evaluate the efficiency of nanoscale zero-valent iron-zeolite (nZVI-Z) and nano-Fe/Cu zeolite (nFe/Cu-Z) adsorbents.
• To investigate the influence of factors like pH, contact time, and concentration on strontium adsorption.

Main Methods:

• Response surface methodology with central composite design was employed for statistical optimization.
• nZVI-Z and nFe/Cu-Z were synthesized and utilized as adsorbents.
• Adsorption experiments were conducted, and isotherm models (Tόth, Langmuir, D-A, Freundlich, Hill) were fitted.

Main Results:

• Maximum strontium removal was observed at pH 12, 200 mg L^-1 initial concentration, and 30 min contact time.
• Adsorption capacities reached 32.5 mg/g for nZVI-Z and 34 mg/g for nFe/Cu-Z.
• Initial concentration and contact time were the most significant factors, with a notable interaction effect.

Conclusions:

• The Tόth isotherm model best described strontium adsorption.
• Optimized conditions and novel adsorbents demonstrate high efficiency for strontium removal.
• Understanding factor interactions is key for developing effective multi-mechanism strontium removal strategies.