title: Laboratory appraisal of organic carbon changes in mixtures made with different inorganic wastes.
abstract: Mixtures of organic and inorganic wastes were incubated to examine the changes in organic C (OC) contents. An anaerobic sludge and a CaO-treated aerobic sludge, with OC concentrations of 235 and 129 gkg(-1), were used. The inorganic wastes used - referred to as "conditioners" - were shot blasting scrap, fettling, Linz-Donawitz slag, foundry sand (FS), and fly ash from wood bark combustion (FA). The total OC (TOC) and KMnO(4)(-) oxidized OC were determined. DTA-TGA profiles and FTIR spectra were also obtained. Mixtures made with the FS contained significantly lower (P<0.05) amounts of TOC (45 gkg(-1)) than the rest of mixtures, which was attributed to the non-existence of reactive surfaces in the conditioner and the increased aeration induced by this material. Those made with FA contained significantly higher (P<0.05) amounts of TOC (170 gkg(-1)), which was attributed to: (i) the addition of an extra source of C - black carbon (BC) - in the FA, and (ii) the inhibition of mineralization from the compounds present in this conditioner (e.g., amorphous aluminosilicates, BC). The results highlight the importance of the characteristics of the conditioners on the fate of the OM originating from the sludges.
authors.affiliation: NEIKER, Berreaga, 1. 48160-Derio, Bizkaia, Spain. mcamps@neiker.net
authors.forename: M Camps
authors.initials: MC
authors.lastname: Arbestain
authors.forename: M L
authors.initials: ML
authors.lastname: Ibargoitia
authors.forename: Z
authors.initials: Z
authors.lastname: Madinabeitia
authors.forename: M V
authors.initials: MV
authors.lastname: Gil
authors.forename: S
authors.initials: S
authors.lastname: Virgel
authors.forename: A
authors.initials: A
authors.lastname: Morán
authors.forename: R Calvelo
authors.initials: RC
authors.lastname: Pereira
authors.forename: F
authors.initials: F
authors.lastname: Macías
mesh_terms: D000535:Aluminum / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007501:Iron / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis*; D010070:Oxalates; D010316:Particle Size; D012722:Sewage / Q000737:chemistry*; D012825:Silicon / Q000032:analysis; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D018505:Waste Management / Q000379:methods*
chemical_list: D007220:Industrial Waste; D009930:Organic Chemicals; D010070:Oxalates; D012722:Sewage; D000535:Aluminum; D007501:Iron; D012825:Silicon