e/Grainger challenge

Information
has gloss	eng: The Grainger challenge is a scientific competition to find an economical way to remove arsenic from arsenic-contaminated groundwater. This competition is being funded by the United States National Academy of Engineering and the Grainger Foundation and is meant to help provide safe drinking water to developing countries such as Bangladesh.
lexicalization	eng: Grainger challenge
instance of	(noun) a very poisonous metallic element that has three allotropic forms; arsenic and arsenic compounds are used as herbicides and insecticides and various alloys; found in arsenopyrite and orpiment and realgar atomic number 33, As, arsenic