Methods for improvement of trickling filter plant performance / 
by James C. Brown...[et al.] 
 - Washington, D.C. :  United States Government Printing Office,  1973 
 - v. :  ill. ;  28 cm. 
 - Environmental Protection Technology Series .
<br/><br/> EPA-670/2-73-047a  Library has pt. 1 
<br/><br/>Part 1. Mechanical and biological optima 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Environmental protection
<br/><br/><label>Dewey Class. No.: </label>363.7