VARIABILITY OF FIELD SOLIDIFIED WASTE

The properties of solidified waste prepared in the field can be antici pated to be more variable than those of solidified samples prepared in the laboratory, because of the greater difficulty in controlling para meters such as untreated waste and binder homogeneity, accuracy of dos age, mixing efficiency, changes in handling characteristics caused by scale-up, etc. However, there is little information available regardin g the effect of field variability on solidified waste properties, In a field trial conducted by the Wastewater Technology Centre it was foun d that the proportions of the waste (electric are furnace dust) and bi nder (activated blast furnace slag) could be controlled within 2%, exp ressed as a fraction of the mix. Comparison of comprehensive physical and chemical test results for laboratory and field solidified specimen s of electric are furnace dust showed that the physical properties of the field solidified material were sensitive to changes in water addit ion, Chemical properties and leachability were most affected by change s in pH and acid neutralization capacity. However, both physical and c hemical properties remained within the desired range. (C) 1997 Elsevie r Science B.V.