Environmental Energy & Engineering - Technologies

Conventional Digestion


Completely mixed digesters normally process slurries having a solids content of 4 to 8% whereas plug flow anaerobic reactors are used to digest slurries having a solids content of 8 to 14%. The methane content of the gas produced is dictated by the chemical composition of the waste. Conventional digestion requires large tanks since the Solids Retention Time (SRT) is equal to the Hydraulic Retention Time (HRT). It is the solids retention time (SRT) that determines the percent of the influent solids that are converted to gas and thus the gas yield.

Anaerobic digestion is normally followed by a separation device that concentrates the residual solids and produces a dilute liquid effluent containing most of the soluble products. Coarse separators such as slope screens or screw presses remove very little fine particulate matter that contains the nitrogen and phosphorus. E3 has developed economical separation technology that capture a substantial portion of all particulate and colloidal solids and nutrients.