ORIGINAL ARTICLE Changes of biochemical properties and heavy metal bioavailability in soil treated with natural liming materials Samy A. M. Abd El-Azeem • Mahtab Ahmad • Adel R. A. Usman • Kwon-Rae Kim • Sang-Eun Oh • Sang Soo Lee • Yong Sik Ok Received: 12 July 2012 / Accepted: 11 March 2013 / Published online: 26 March 2013 Ó Springer-Verlag Berlin Heidelberg 2013 Abstract This study evaluated the efficiency of naturally occurring lime-based waste materials (oyster shells, egg- shells, and mussel shells) on immobilization of selected heavy metals (Cd and Pb) and a metalloid (As) in a con- taminated agricultural soil. A 30-day incubation experi- ment was performed using soil mixture with natural liming materials or calcite (CaCO 3 ) at 0, 1, 3, 5, and 10 wt %. Soil biochemical properties including pH, electrical conductiv- ity (EC), exchangeable cations, organic matter (OM), total nitrogen (TN), microbial populations, and enzyme activi- ties were determined to ensure the changes in soil quality during incubation. The results showed that the application of natural liming materials led to an increase in soil pH similar to that of CaCO 3 . Soil concentrations of Cd, Pb, and As extracted with 0.1 or 1 M HCl, and diethylene triamine pentacetic acid (DTPA) were decreased significantly after adding liming materials, accompanied by increased microbial population and enzyme activities of dehydroge- nase, phosphatase, b-glucosidase, and arylsulfatase. Addi- tionally, eggshells and mussel shells induced significant increases in OM and TN in the soil. Application of natural liming materials offers a cost-effective way to immobilize heavy metals and metalloids in soils. Keywords Heavy metals Á Immobilization Á Remediation Á Soil enzyme Á Soil quality Introduction Contamination of soils with heavy metals represents a worldwide environmental concern (Alkorta et al. 2010). Mining is one of the most important sources of heavy metal contamination to the environment (Ok et al. 2011a). Korea has a long history of metalliferous mining, and the most extensive mining activities occurred during the early twentieth century (Lee et al. 2001; Ok et al. 2011a). Due to decreasing availability or demand, the abandoned mines in Korea have become a releasing source of heavy metals such as Cd, Pb, and As into nearby agricultural soils (Lee et al. 2001; Yang et al. 2006, 2008; Ok et al. 2010). It is likely to cause chronic and acute diseases to humans via ingestion of food crops contaminated with heavy metals (Ok et al. 2004; Yang et al. 2007). Therefore, several remediation technologies for contaminated agricultural soils have been developed so far. Ex situ traditional physicochemical remediation methods for soils contami- nated with heavy metals are generally achievable; how- ever, they are very costly and often damages soil quality (Alkorta et al. 2010). On the other hand, in situ remediation could be logical and rational methods because of less tur- bulence of soil (Fernandez-Caliani and Barba-Brioso 2010; Ok et al. 2011b, c). Chemical immobilization remediation is adapted in in situ methods using amendments for reducing metal mobility and availability via adsorption, precipitation, and complexation (Chen et al. 2000; Moon et al. 2011; Ahmad et al. 2012a). Numerous amendments have been widely examined for in situ immobilization of metals, including S. A. M. Abd El-Azeem Á M. Ahmad Á A. R. A. Usman Á S.-E. Oh Á S. S. Lee (&) Á Y. S. Ok (&) Department of Biological Environment, Kangwon National University, Chuncheon 200-701, Korea e-mail: sslee97@kangwon.ac.kr Y. S. Ok e-mail: soilok@kangwon.ac.kr K.-R. Kim Department of Agronomy, Oriental Medicine Resource, Gyeongnam National University of Science and Technology, Jinju 660-758, Korea 123 Environ Earth Sci (2013) 70:3411–3420 DOI 10.1007/s12665-013-2410-3