Wastewater Treatment Primary Treatment Britannica
wastewater treatment wastewater treatment primary treatment: primary treatment removes material that will either float or readily settle out by gravity. It includes the physical processes of screening, comminution, grit removal, and sedimentation. screens are made of long, closely spaced, narrow metal bars. they block floating debris such as wood, rags, and other bulky objects that could secondary aluminum production: neshap: chromium electroplating: chrome electroplating: decorative, hard, and chromic acid anodizing lead processing: primary lead processing: neshap: lead smelting: standards of performance for primary lead smelting: primary nonferrous metals -zinc, cadmium, and beryllium area sources: neshap:zinc is the rd most abundant element in the earths crust. sphalerite, zinc sulfide, is and has been the principal ore mineral in the world. zinc is necessary to modern living, and, in tonnage produced, stands fourth among all metals in world production being exceeded only by iron, aluminum, and copper.