Intensified depolymerization of aqueous polyacrylamide solution using combined processes based on hydrodynamic...

Area of Science:

• Chemical Engineering
• Environmental Science
• Materials Science

Background:

• Polyacrylamide (PAM) is widely used but its depolymerization is challenging.
• Conventional methods for PAM degradation are often inefficient or environmentally taxing.

Purpose of the Study:

• To investigate and optimize intensified depolymerization of polyacrylamide (PAM) solutions.
• To evaluate the synergistic effects of combining hydrodynamic cavitation (HC) with chemical (H2O2, O3) and physical (UV) oxidation methods.

Main Methods:

• Depolymerization of PAM solutions using hydrodynamic cavitation (HC) reactors.
• Application of combined treatment methods: HC+UV, HC+O3, HC+H2O2, UV+H2O2, UV+O3, and HC+UV+H2O2.
• Investigation of parameters like inlet pressure for HC and power for UV irradiation.
• Characterization of treated PAM using Fourier Transform Infrared (FTIR) spectroscopy.

Main Results:

• Combined approaches significantly enhanced PAM depolymerization compared to individual methods.
• The HC+UV+H2O2 combination achieved 97.27% viscosity reduction under optimized conditions (3 bar HC, 8 W UV, 0.2% H2O2).
• FTIR analysis confirmed no significant changes in the chemical structure of the treated PAM, indicating depolymerization without altering the polymer backbone.

Conclusions:

• The synergistic combination of hydrodynamic cavitation, UV irradiation, and hydrogen peroxide offers a highly efficient method for polyacrylamide depolymerization.
• This integrated approach presents a promising strategy for treating PAM-containing wastewater or for recycling PAM.
• Optimized process parameters are crucial for maximizing depolymerization efficiency.