TY - BOOK ED - Water Environment Federation. ED - Environmental and Water Resources Institute (U.S.) TI - Biological nutrient removal (BNR) operation in wastewater treatment plants T2 - WEF manual of practice SN - 0071464158 PY - 2006/// CY - New York PB - McGraw-Hill KW - Sewage KW - Purification KW - Nutrient removal N1 - 'Manual of practice no. 30'--Cover; Includes bibliographical refrences and index ER -