English: This is an upgraded version of en:Aerated Sludge 1.jpg which was uploaded by Kekel on July 4, 2006. The reasons for upgrading the image are: (1) To convert the lossy jpg (which already has visible artifacts) to the non-lossy png format. (2) To shorten the width of the image (from 417px to 300px) so that it can placed on the right side of a Wikipedia article and still have room for the article text. {3) To rename it from "Aerated Sludge 1" to the more appropriate "Activated Sludge 1", since it is now and will continue to be used in the en:Activated Sludge article. The actual changes to the original version are quite minor and the actual appearance of the upgrade version is almost identical with the original. I will retain the same license as used by the original uploader.