Evaluation of Crop Growth and Soil Chemical Properties in Cadmium Contaminated Soil Using Biochar Derived from Rendered Animal Carcass Residues

Abstract

Rendering process is known as a quick and stable method that copes with dead livestock by extracting and purifying the animal's fat and others through the heat treatment at high temperature and with high pressure. However, a large amount of solid byproducts equivalent to 15% of the weight of carcasses after this process are discharged, and some of them are provided as livestock feed and compost, but others are landfilled since the processed byproducts must go through the secondary process again. It is judge that RACR (rendering animal carcass residue) has a high utilization value since it is composed of protein and bone tissues and a very high domestic applicability as it can secure a rich amount of it. Therefore, in this study, the effects of biochar derived from rendered animal carcass residues were evaluation on crop growth characteristics and soil chemical properties in cadmium contaminated soil. The results of pot experiment showed the process with RACR-C (rendering animal carcass residue biochar) had the effect of soil amendment that increased the pH, organic content, available phosphate, and cation exchange capacity in the contaminated soil. In addition, the analysis of phyto-availability of cadmium by 1 M NH 4 NO 3 sampling method showed there was an effect of reducing cadmium transfer by 26 to 98% depending on the amount of processed biochar compared to the untreated control plot and also effective in promoting the growth of radish, such as fresh weight, leaf number. Thus, it is judged that the biochar produced with the rendering animal carcass residue biochar can be applicable as a soil stabilizer during the process of cadmium-contaminated soil, and eco-friendly and economically efficient in terms of waste resource recycling.