Study type: Medical/biological study (experimental study)

The influence of microwave heating on the characteristics of polyelectrolytes. med./bio.

Published in: J Microw Power Electromagn Energy 2000; 35 (4): 216-224

Aim of study (acc. to author)

In the acrylamide co-polymer production, the problem of reducing electrical energy consumption is especially important (expense factor). The aim of the study was: 1) to study the effects on the polyelectrolyte characteristics under the following factors: type of energy inducing the polymerization process (classical heating, microwave heating, electron beam irradiation, and simultaneous microwave and electron beam irradiation), chemical composition of the solutions to be irradiated and microwave and/or electron beam parameters;
2) to improve the polyelectrolyte parameters;
3) to develop new technologies based on microwave heating or simultaneous microwave + electron beam treatment in the field of polyelectrolytes used for wastewater treatment.

Background/further details

For the preparation of polymeric flocculents the interest was focused on the basic optimization of the characteristics involved in wastewater treatment.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Exposure duration: 30 s - 135 s
Exposure 2: 2.45 GHz
Exposure duration: 30 s - 135 s

Exposure 1

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration 30 s - 135 s
Exposure setup
Exposure source
  • Magnetron MI850
Setup multimode rectangular cavity: 450 x 245 x 245 mm³
Parameters
Measurand Value Type Method Mass Remarks
power 850 W maximum - - output power

Exposure 2

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration 30 s - 135 s
Exposure setup
Exposure source
  • Magnetron MI2250
Setup multimode rectangular cavity: 450 x 245 x 245 mm³
Parameters
Measurand Value Type Method Mass Remarks
power 2,250 W maximum - - output power

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Microwave heating produces high water solubility of acrylic acid co-polymer but median molecular weight values; electron beam irradiation gives high molecular weight values but associated with a cross-linked structure (poor water solubility), while microwave energy addition to electron beam energy gives simultaneously high molecular weight values and high acrylamide and acrylic acid co-polymer water solubility.
The main conclusion is that chemical composition and absorbed energy per mass unit must be controlled and optimized in order to obtain both high molecular weight and good water-solubility.

Study character:

Study funded by