Sequential nitrification-denitrification in a plug flow activated sludge system /

Mode of access: Internet.

Study of gate valves and globe valves as flow regulators for irrigation distribution systems under heads up to about 125 feet of water /

Mode of access: Internet.

Two-phase anaerobic digestion for enhanced stabilization and methanation of sewage sludge /

"ILENR/AE-92/02."

Use of solar energy to heat anaerobic digesters : part I, technical and economic feasibility study : part II, economic feasibility throughout the United States /

Mode of access: Internet.