Acidic Soil Improvement and Physicochemical Characteristics Using Red-mud and Biochar

Abstract

Objectives Total waste that is generated in South Korea per land area is ranked in fourth among OECD countries. Therefore, the importance of resource circulation through waste recycling should be emphasized. Red mud, one of the industrial wastes, is a by-product of the aluminum smelting process and is generated about 30 million tons per year. Methods Red mud is high in iron content and has a red color and strong alkalinity. Rice husk, a by-product of agricultural production, can be made into biochar through pyrolysis process and it also has alkalinity. By using red mud and biochar as soil amendment, experiment was conducted. The purpose of the experiment is to improve the quality of the acidic soil and find the growth-characteristics (length, width, weight, dry weight) through pot experiment. Results and Discussion The acid soil with a pH level of 4.84 was increased to pH 7.14 after adding the amendment. The CEC of the soil with 7.56 cmolc/kg was increased to 9.80 cmolc/kg. Pot experiment showed better results of growth-characteristics in treatment than control. The analysis of heavy metals showed below standard level in both control and treatment. Conclusion Therefore, the pot experiment showed that red mud and biochar could be used to improve acid soil effectively. Key words: Red Mud, Biochar, Soil Improvement, Amendment, Acidic Soil