


Diagram from sewage treatment plan for Philadelphia, 1912

Southwest Sewage Treatment Plant under construction, 1949

Emscher Tank Installation at Essen Nord, Germany

Volume of Sludge from 1,000,000 Gallons of Sewage

Diagram Showing Rate Between Bulk of Wet Sludge and Its Percentage Moisture

Sludge Drying Beds, Essen Nord, Germany

Grit Chamber, Essen, Germany

Effects of Expansion of Gas Bubbles in Enscher Sludge Shown in Right-Hand Cylinder

Sludge Presses for Grease Recovery, Bradford, England

Drain water from sludges obtained from sedimentation, septic and Emscher tanks
