Study of Red Mud Improvement with the Mixing Method and the Impact of Pennisetum hybridum Plantation on Red Mud Amendment

currently, the comprehensive utilization of red mud has been a worldwide challenge. Due to high alkaline level and a serious lack of nutrients, a great amount of red mud has been stocked in the open rather than covered by plantations, which showed harms to the atmosphere, water and soil environment. In order to explore a more effective phytoremediation approach of red mud and screen plants with strong tolerance, the research group applied Pennisetum hybridum as the experiment material for a long term, which is a new energy plant in the field of ecological environmental management and restoring. Through the addition of different types of addictives, his experiment conducted the plantation Pennisetum hybridum based on red mud improvement matrix. Besides, a systematic research of the improvement effects of different ameliorants on red mud was conducted. Concurrently, the growth of Pennisetum hybridum in different groups of the experiment was investigated. Their mutual effect on the improvement effect of red mud was analyzed systematically. Results demonstrated that effective raw materials of red mud improvement include phosphogypsum, wastes of polluted and edible mushrooms. These can significantly reduce the pH and conductivity of red mud. After the improvement, Pennisetum hybridum can grow vigorously in the mixture matrix of red mud, and significantly improve the red mud matrix. Concurrently, considerable biomasses were obtained. The experiment results demonstrated that the addition of necessary nutriments for the plant growth was very important for red mud. The research has laid a solid foundation for the identification of the great potentials of Pennisetum hybridum in red mud phytoremediation, the further exploration of its role of restoring of red mud and the extensive application and promotion in the future.