New application of polyurethane as porous hydrogel carrier for microorganisms of waste water treatment

Porous polyurethane urea hydrogel (PU-gel) was prepared by the reaction of copoly(ethyleneoxide-propyleneoxide)triol terminated with toluene diisocyanate and water. The hydrogel was highly compatible with microorganisms and had good mechanical properties. This hydrogel was found to be very suitable for the newly developed biological nitrogen removal process of wastewater. In the biological reactor of the process, the porous hydrogel cubes on which the nitrification bacteria were fixed promote very quick nitrification of the nitrogen sources in the wastewater. Here we report the characteristics of the porous polyurethane urea hydrogel and the performance of the biological nitrification process using this hydrogel as a floating carrier of microorganisms.