2results about How to "Reduce total nitrogen" patented technology

This utility model discloses an artificial enhanced aquatic ecosystem restoration system, mainly relating to the field of aquatic ecosystem restoration technology. The artificial enhanced aquatic ecosystem restoration system of this utility model is characterized by comprising a pretreatment system, an enhanced denitrification system, an artificial wetland system, a main control system, and a power supply system. The artificial enhanced aquatic ecosystem restoration system of this utility model has high removal efficiency for suspended solids, organic matter, and pollutants such as nitrogen and phosphorus in water bodies. Compared with existing technologies, this utility model has advantages such as enhanced denitrification, high integration, low carbon emissions and energy saving, good treatment effect, and low operating cost.

The application discloses a preparation method of 700MPa girder steel with excellent low-temperature toughness for high-cold regions, and belongs to the technical field of steel metallurgy, and comprises the following steps: S1, selecting a low-carbon mode for converter smelting, suppressing nitrogen increase through top and bottom combined blowing to strengthen the molten pool stirring, performing slag washing when tapping, and forming slag in advance; S2, LF refining, controlling nitrogen under 0.2MPa micro-positive pressure, creating low-melting-point refining slag and extreme desulfurization, removing large-size non-metallic inclusions, and performing modification treatment on residual MnS and Al2O3 by calcium treatment to remove small-size non-metallic inclusions; S3, full-process protection pouring of slab continuous casting, optimizing the electromagnetic stirring of the crystallizer, dynamic soft reduction, and cooling capacity of the secondary cooling zone under the premise of low superheat, and shortening TiN precipitation time; and S4, sequentially performing heating, rough rolling and finish rolling, and performing finish rolling in the austenite region, and rapidly cooling high-temperature austenite by low coiling, so that TiN is precipitated in a finer and more dispersed form.