Wei Zheng, Illinois Sustainable Technology Center (image) University of Illinois at Urbana-Champaign Share Print E-Mail Caption Illinois Sustainable Technology Center senior research scientist Wei Zheng and his colleagues found that estrogenic compounds in dairy waste biodegrade very slowly in the absence of oxygen. Credit L. Brian Stauffer Usage Restrictions Photo may be used only with stories about the research described in this release. Credit required Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.