굴껍질과 가축뼈를 이용한 납, 구리로 오염된 사격장 오염토양의 안정화

Abstract

The soil is one of the important elements in the ecosystem, which the life originates from and lives in. The environment has been dramatically degraded with the accelerated industrialization from the mid 20th century and the soil environment has also been polluted in various channels including the mining and refining activities or military facilities, etc. Although there are over 1,400 shooting ranges where the pollution has been intensified with a lot of copper and lead every year, it is true that surveys or measures on them are lacking. Considering such realities, this study applied the solidification/stabilization engineering methods to the soil directly taken from the shooting ranges of military bases in Busan, and then analyzed their efficiency and mechanism. Although the solidification/stabilization engineering methods are widely used over the world due to their economy and applicability, their actual use in our country is lacking. The highest concentration of both lead and copper in the soil taken from the shooting ranges was 8,106mg/kg and 286mg/kg respectively under 0.1N HCl extraction. This study carried out the experiment by processing the waste oyster shells and livestock bones that have been processed with wastes by the solidification/stabilization agent. The waste oyster shells were filtered with a 10 mesh sieve through a crasher and calcined for two hours at 900℃. As a result of the XRD analysis, main elements in the waste oyster shell before and after calcination were CaCO3 and CaO, while mein elements in the live stock bone were P and Ca from the XRF analysis. The main mechanism to stabilize lead and copper is known to be the physical sealing with the creation of hardening response materials such as CSH and CAH, the formation of precipitation in a very low Ksp value through the molecular bonding or sorption, etc. Although any bonding substance could not be identified in the XRD analysis due to the low detection limit, many crystals, which could be assumed as the precipitation containing heavy metals could be observed through the SEM-EDS analysis. As a result of the experiment, the application of stabilizers using the waste oyster shell showed values compliant to the standard 'A' under the Soil and Environment Preservation Act for both lead and copper from the KST analysis with good results even from the TCLP experiment while demonstrating very good results in stabilizing lead when the waste oyster shells were mixed with the livestock bones in the application.