Jesus Andres Cacho Rivero

Born in Laredo (Cantabria) Spain

M.S and B.S. Chemistry. University of Valladolid. Spain

PhD Student since 2000 in Dr. Suidan Research Group

Department of Civil & Environmental Engineering

Anaerobic Digestion of Excess

Municipal Sludge.

Enhancement of Solids Destruction

Production of excess municipal sludge is increasing with increases in population,

industrial activity, and the level of treatment. There is an urgent need to develop

technology that permit for safe and efficient disposal of this sludge.

Anaerobic digestion is an environmentally friendly and economically sustainable

technology for the disposal of excess municipal sludge. This technology,

however, suffers from the fact that a maximum of only 50 % of the organic solids

are destroyed during treatment.

The objective of this study, which is being performed in the Civil and

Environmental Engineering Department of University of Cincinnati, is two-fold:

Perform fundamental research to determine the effect of the sludge

retention time and the hydrodynamics on digestion.

Select and optimize a co-treatment system to enhance the performance of

solid destruction during the anaerobic digestion process.

Experimental Set-Up

Twelve well mixed lab-scale anaerobic reactors set up in a

constant temperature (37°C) room

Versatility to conduct simultaneous

parametric studies

Theoretical Studies

Solids Removal as a function of Sludge Retention Time (SRT)

Four different retention times (5, 10, 20 and 40 days) were evaluated in triplicates. The solids removal obtained was modeled as a function of the SRT Model:

Evaluate the benefit of reactor staging

Multiple stage configurations were compared to single stage reactors having the same SRT. Staging resulted in increases in solids removal ranging from 2 to 5 %.

Proposal Treatments Studies

Thermal, Oxidative and Thermo-oxidative treatment of excess municipal sludge

The use of low temperature (below 100°C) and hydrogen peroxide was evaluated as

pretreatment and co-treatment options of anaerobic digestion Results: