ABSTRACT
Contamination of elevated heavy metal(loid)s (HMs) in soils can adversely affect soil ecology, agricultural productivity, quality of agricultural products and water resources, as well as human and animal health (Raicevic et al. 2005; Thawornchaisit and Polprasert 2009; Kabata-Pendias 2011; Shaheen et al. 2013, 2014a,b). The improper management of metallurgical industrial wastes and mining wastes usually causes soil contamination with toxic HMs (e.g., arsenic [As], cadmium [Cd], chromium [Cr], cobalt [Co], copper [Cu], mercury [Hg], nickel [Ni], lead [Pb], selenium [Se], and zinc [Zn]) (Hooda 2010). Increasing awareness of the environmental and public health hazard of toxic HMs pressurizes society to develop management strategies to remediate or restore the contaminated areas. As land treatment is considered an important waste management practice, soil becomes a major source of HMs entering the food chain mainly through plant uptake and animal transfer (Rogival et al. 2007; Zhuang et al. 2009; Shaheen et al. 2014b,c).
