Vol.:(0123456789) 1 3 Bulletin of Environmental Contamination and Toxicology https://doi.org/10.1007/s00128-019-02573-6 Efective Role of Biochar, Zeolite and Steel Slag on Leaching Behavior of Cd and Its Fractionations in Soil Column Study Saqib Bashir 1,2  · Abdus Salam 1  · Muzammal Rehman 5  · Shahbaz Khan 4  · Allah Bakhsh Gulshan 3  · Javaid Iqbal 4  · Muhammad Shaaban 1  · Sajid Mehmood 1  · Anaam Zahra 3  · Hongqing Hu 1 Received: 7 December 2018 / Accepted: 11 February 2019 © Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract Remediation of cadmium (Cd) from contaminated soils is considered a complicated task of environmental safety. A column leaching experiment was planned to estimate the infuence of biochar (BC), zeolite (ZE) and steel slag (SL) at 1.5% and 3% application rate on Cd leaching behavior and chemical fractionation in contaminated soil. A sequential extraction procedure, the European Community Bureau of Reference (BCR), Toxicity Characteristic Leaching Procedure (TCLP) and NH 4 NO 3 were performed after leaching was completed. The soluble portion of Cd was decreased by 36.3%, 18.4% and 28.7% and Cd contents in leachate were decreased by 44.8%, 30% and 31.3% after BC, ZE and SL addition at 3% rate, respectively over control soil. The greater reduction in TCLP extractable Cd was observed by 29.6% with BC and 22.4% with ZE and 25.7% with SL at 3% application rate. Overall, biochar can be considered an efcient soil amendment to reduce Cd leaching as well as increased its stabilization within soil profle. Keywords Cadmium · Immobilization · Passivators · Leaching · Sequential extraction Accumulation of heavy metals in farmlands is creating the serious environmental threat due to excessive use of fer- tilizers, pesticides and waste water for irrigation (Ahmad et al. 2014; Lu et al. 2014). Particularly, in China about 16.76% of farmland soils are reported to be contaminated with heavy metals, in which Cd contamination has major share (Song et al. 2013). Frequent use of agricultural prod- ucts into soil induces Cd contamination about 10 million hectares of agricultural soils of China (Song et al. 2013). Chinese Ministry of Environmental Protection classifed Cd residues for agricultural soils as a strong hazardous material (Song et al. 2013). In order to minimize the chances of heavy metal efects on soil and living organisms, it is urgent need to overcome the soluble and easily exchangeable form of Cd in agricultural soils (Bashir et al. 2018a, b). In past decades, several eco-friendly and cost efective remediation options have been introduced to metal contaminants to improve soil good health such as excavation, land flling, soil washing (Ahmad et al. 2014). But now a days, in-situ stabilization of heavy metals with organic and inorganic efective stabilizing agents have been getting much attention worldwide (Ahmad et al. 2014; Bashir et al. 2018a, b, c). In-situ immobilization techniques focused on use of sev- eral common additives such as organic waste products, clay mineral and industrial products which have been used to overcome the soil stability (Bashir et al. 2018b). In organic waste products, biochar has received much attention for heavy metal stabilization in soil. Biochar is an alkaline car- bonaceous by product of several waste materials such as crop residues, animal manures and vegetables waste produced * Saqib Bashir Saqibbashir416@yahoo.com * Hongqing Hu hqhu@mail.hzau.edu.cn 1 Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China 2 Department of Soil & Environmental Science, Ghazi University, Dera Ghazi Khan, Pakistan 3 Department of Botany, Ghazi University, Dera Ghazi Khan, Pakistan 4 Department of Agronomy, Ghazi University, Dera Ghazi Khan, Pakistan 5 College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, People’s Republic of China