Evaluation of Trace Elements from Used Industrial Waste in Soil improvement

The use of industrial waste as an additive in soil improvement has many advantages, including recycling of waste, reducing the need for waste storage, and obtaining an economical material. With the use of these wastes, desired positive results are obtained in some geotechnical properties of soil. However, the wastes can create trace element contamination in soil and groundwater. In this study, trace elements originating from industrial wastes contaminating groundwater are investigated. The industrial wastes were mixed at different proportions with the soil. These mixtures were compacted into a permeameter cells, and a seepage tests were performed. The leachates obtained from seepage tests were analyzed with inductively coupled plasma mass spectrometry (ICP-MS) to determine trace elements. The measured trace element quantities were compared with the allowable values in the relevant standards (EPA 822, WHO, TS266). The results reveal that quantitative values of the trace elements from the leachates were within the allowable limits, except for arsenic and chromium. Furthermore, when fly ash is used As and Cr can be combined with ettringite and be immobilized. Boron and silica fume are hazardous substances caused by trace elements. However, considering its long-term effect, they can be used with fly ash.