Utilization of bottom ash for degraded soil improvement for sustainable technology

Bottom ash is one of the main products from coal combustion in coal-fired power plants. It has been applied in many applications such as landfill, cement industry or raw feed for clinker, concrete, etc. Furthermore, it can be used in agriculture to improve soil quality. However, the utilization rate of bottom ash in agriculture is still very low only 0.1% of bottom ash. The properties of bottom ash can adjust the pH in soil and provide some nutrients to improve soil quality. Moreover, the soil degradation is a major problem in agricultural countries. The soil degradation is the decline in soil quality due to the improper land use, agriculture with misuse or excess use of fertilizers and so on. In Thailand, the soil degradation is a serious problem in agriculture in the northern mountainous areas. The mainly causes of soil degradation are from human activities such as overuse of pesticide, herbicide, and fertilizer, deforestation, expansion of cultivated areas. Therefore, the objective of this research is to apply the bottom ash from Mae-Moh power plant to improve soil quality of degraded soil in Nan province, Thailand and to investigate the effects of amount of bottom ash from 0-30% by weight on some parameters such as pH, electrical conductivity (EC), bulk density and soil texture. From the result, it is clear that with higher amount of bottom ash, the quality of degraded soil has been improved especially pH and soil texture. The pH can increase from 5.664 up to 7.408. Soil texture can change from clay to loam or sandy loam. The bulk density of soil decreases at all rates of bottom ash which is favorable for plant growth. This research can be applied for soil amendment and is expected to improve the yield for plant growing. Furthermore, the practical combinations of 10% and 20% of bottom ash are considered to apply in the real field to evaluate the improvement on soil properties in the future.