Impacts of the use of magnesia versus iron on mesophilic anaerobic digestion and odors in wastewater

Addition of iron to sewer lines for chemical phosphorus removal is widely practiced around the world. However, high dosage of iron may prove detrimental to the anaerobic digestion process and also lead to higher organic sulfur odors and deteriorating biosolids quality. The following research focuses on finding an alternative to the use of iron in wastewater systems by comparing the roles of iron and magnesium on mesophilic anaerobic digestion, the digested effluent characteristics and odors in biosolids. Three anaerobic digesters were operated, one serving as a control with no additives, and the other two having known doses of iron and magnesium added. Comparison of the effluent characteristics revealed an improvement in the overall performance of the magnesium amended digester (in terms of pH, solids and COD reduction, alkalinity and gas production) over the other two reactors, suggesting the benefits of magnesium addition. Both iron and magnesium were found to be effective in achieving high levels of phosphate removals and reducing nuisance odors in dewatered sludge cakes.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Civil Engineering

Department dc:contributor.department

Civil Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2011

Author dc:creator

• Radhakrishnan, Kartik

Chair dc:contributor.committeechair

• Novak, John T.

Committee members dc:contributor.committeemember

• Knocke, William R.
• Little, John C.

• nutrient removal
• struvite
• biosolids
• mesophilic anaerobic digestion
• iron
• magnesium
• dewatering
• odors

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-09202011-163122

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/35129