title: Sizes of particles formed during municipal wastewater treatment.
abstract: Volumetric diameters Dv and specific surface area SpS of sludge particles formed during chemical coagulation and electrocoagulation of sewage were determined. The obtained aggregate-flocs differed substantially in both Dv and SpS values. The differences in Dv and SpS values of the analyzed particles were interpreted based on theoretical models for expanding aggregates. The most uniform particles were formed under exposure to: (a) optimal and maximal doses of PIX, (b) optimal doses of PAX, (c) maximal doses of the Al electro-coagulant. The lowest PIX dose produced the least uniform particles. Sludge aggregates-particles produced under exposure to minimal doses of PIX and the Al electro-coagulant were characterized by the lowest SpS values. Sludge particles coagulated by PAX and the particles formed at higher doses of PIX and the Al electro-coagulant had higher SpS values. The particles formed at all doses of the applied coagulants and electro-coagulants were generally classified into two size ranges: the main range and the secondary range. Most particles belonged to the main size range. An increase in the percentage of colloidal hydroxide particles in sewage sludge increased SpS.
authors.affiliation: Faculty of Environmental Management and Agriculture, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland E-mail: lechs@uwm.edu.pl.
authors.forename: Smoczynski
authors.initials: S
authors.lastname: Lech
authors.affiliation: Faculty of Environmental Management and Agriculture, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland E-mail: lechs@uwm.edu.pl.
authors.forename: Kosobucka
authors.initials: K
authors.lastname: Marta
authors.affiliation: Faculty of Food Sciences, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland.
authors.forename: Smoczynski
authors.initials: S
authors.lastname: Michal
authors.affiliation: Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Aas, Norway.
authors.forename: Ratnaweera
authors.initials: R
authors.lastname: Harsha
authors.affiliation: Faculty of Environmental Management and Agriculture, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland E-mail: lechs@uwm.edu.pl.
authors.forename: Pieczulis-Smoczynska
authors.initials: PS
authors.lastname: Krystyna
mesh_terms: D057919:Biological Oxygen Demand Analysis; D005427:Flocculation; D008962:Models, Theoretical; D010316:Particle Size; D011044:Poland; D012722:Sewage / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D012722:Sewage; D062065:Wastewater