A method for recovering silicon from red mud to prepare calcium silicate to remove nitrogen and phosphorus in water

Abstract

The invention discloses a method for removing nitrogen and phosphorus from water by using calcium silicate prepared from silicon recycled from red mud, and relates to a method for removing nitrogen and phosphorus from water. By the method, the problems of waste resource utilization and removal of excess nitrogen and phosphorus from water are solved. The method comprises the following steps: leaching most of metal oxides from the red mud by using dilute hydrochloric acid first and then leaching titanium and rare earth elements from the red mud by using concentrated sulfuric acid so as to leave silicon dioxide powder, and then preparing the extracted silicon dioxide into calcium silicate by a hydrothermal method. A certain amount of calcium silicate is added into waste water containing nitrogen and phosphorus, the waste water is oscillated at a certain temperature, ammonia nitrogen is removed from water through gas-liquid separation, and phosphorus is removed from water through ligand exchange and chemical precipitation.

Description

Technical field [0001] The invention relates to a method for recycling wastes and simultaneously removing nitrogen and phosphorus from water Background technique [0002] In recent years, with the continuous development of my country's economy, the structure of industry and agriculture has also been adjusted. With the continuous development of the aluminum industry, a large amount of red mud waste is produced. The bottleneck restricting the sustainable development of my country's aluminum industry, the removal of red mud waste is a major problem in my country's aluminum industry. The accumulation of red mud will cause a large amount of waste lye to infiltrate the nearby land, causing soil alkalization and swamping, polluting the surface and underground water sources. Long-term drinking of such water sources will affect your health. Dealing with red mud is a serious problem. The large-scale livestock and poultry breeding industry in my country has developed rapidly and has beco...

AI Technical Summary

Problems solved by technology

However, a large amount of livestock and poultry wastewater has brought a series of environmental pollution problems, and the pollution is relatively concentrated and difficult to deal with.

The direct discharge of wastewater from livestock and poultry farming will not only pollute surface water bodies and cause eutrophication, but also cause damage to groundwater and farmland ecosystems, and even endanger human health

Poor biodegradability due to high ammonia nitrogen condition