The effect of flyash on the removal of soluble phosphate from solution

An economical process for the elimination of nutrients to receiving waters.is a major problem now facing modern wastewater treatment. The purpose of this investigation was to determine the feasibility of soluble phosphate removal in a flyash contact system. The investigation consisted of experiments involving batch adsorption studies and continuous flow studies. Removal kinetics and relationships between contact time, “t” , and flyash concentration, “D_f”, were evaluated using batch adsorption techniques. Of the two flyash samples tested the high alumina content flyash exhibited the best rate of phosphate removal. The high alumina content flyash yielded an average removal capacity of 2.47 x l0⁻⁴ grams of phosphorus per gram of flyash, whereas the low alumina content flyash yielded an average capacity of only 1.61 x 10⁻⁴ grams of phosphorus per gram of flyash. Continuous flow operations were conducted using both types of flyash so as to observe the removal in an actual process situation. The phosphate removal was concluded to be both physical and chemical in nature, with two removal mechanisms predominating. The primary physical mechanism involved the phosphate adsorption on the alumina surface found in the flyash. The chemical removal mechanism was postulated to be the precipitation of phosphate as Mg₃(PO₄)₂ and Ca₃(PO₄)₂ at pH levels above 8.0.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Sanitary Engineering

Department dc:contributor.department

Sanitary Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1970

Author dc:creator

• Rowell, Evander Hoyt

Statement dc:rights

• In Copyright

Licence dc:rights.uri

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

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/71048

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/71048