9results about How to "Reduce total nitrogen" patented technology

The invention relates to the technical field of sludge treatment, and discloses a sludge treatment method based on sludge reduction and ammonia nitrogen recovery, which comprises the following steps: 1) alkali thermal hydrolysis: adding alkali into sludge to adjust the pH value to 9-11, and carrying out thermal hydrolysis reaction; (2) wet oxidation: heating after reaction and discharging, and carrying out wet oxidation reaction; (3) flash evaporation: carrying out heat recovery after reaction discharging, and carrying out flash evaporation to obtain a sludge mixed solution and flash evaporation steam; (4) dewatering: performing heat recovery on the sludge mixed solution, and then dewatering to obtain a sludge cake and filtrate; and (5) ammonia nitrogen air stripping: carrying out ammonia nitrogen air stripping on the filtrate by adopting steam, wherein the filtrate after air stripping can be reused as a carbon source for sewage treatment. According to the method, the oxidative degradation efficiency of the sludge is improved through coupling of alkali thermal hydrolysis and wet oxidation treatment, ammonia nitrogen recovery and sludge reduction are facilitated, and the filtrate has the characteristics of high COD and low total nitrogen and is more suitable for being used as a carbon source.

This invention discloses a method for controlling sulfides in sulfur-containing gear steel, belonging to the field of metallurgical technology, including converter, LF refining, RH refining, and continuous casting processes. Converter process: molten steel tapping temperature 1630±20℃, carbon-oxygen product controlled below 0.0020; LF refining process: aluminum content in molten steel controlled at 0.035-0.045%, LF slag composition adjusted to R: 1.5-2.5, FeO+MnO: 1.0-2.0%; RH refining process: ferrotitanium added in one step to adjust the composition appropriately; Continuous casting process: argon-blown stopper rods and submerged entry nozzles are used for continuous casting, and 150-200 kg of low-basicity tundish covering agent is added to the tundish. The sulfur-containing gear steel produced by this invention can be continuously drawn for more than 10 heats, and the level of Class A inclusions can be stably controlled at A coarse ≤ 1.0 grade and A fine ≤ 1.5 grade, with a pass rate of over 99.9%.

The invention provides a preparation method of low-nitrogen steel and the low-nitrogen steel, and belongs to the field of smelting. The method comprises the steps that molten iron is smelted in a converter, CO2 and Ar are blown from the bottom in the whole process, and first molten steel is obtained; the converter smelting mode is a low-nitrogen control mode, and the static slag thickness of converter smelting is larger than or equal to 300 mm; the first molten steel is subjected to converter tapping, a first alloy is added in the converter tapping process, and second molten steel with set chemical components is obtained; the second molten steel is subjected to refining treatment, a second alloy is added into the molten steel in the later stage of refining treatment, and third molten steel is obtained; and the third molten steel is subjected to continuous casting, and the low-nitrogen steel is obtained. Through low-nitrogen control based on the converter and by utilizing the influence of different alloy elements on the nitrogen solubility, the adding sequence of the alloy in the smelting process is optimized, the nitrogen increase of molten steel in the smelting process is reduced, the nitrogen control effect of the low-nitrogen steel is improved, and stable production of the low-nitrogen steel is realized.

The invention discloses a tail water treatment system and method for breeding micropterus salmoides offspring seeds by using containers. The bottoms of a plurality of breeding containers of the tail water treatment system are communicated with a tail water collection pipeline through second branch pipelines; the tail water collecting pipeline is also connected with a water inlet of the microfilter; a water outlet of the microfilter is communicated with a drainage ditch in the vineyard through a third branch pipeline; the vineyard is connected with the right side of the ecological pond through a fourth branch pipeline; according to the method, the purpose of planting the weever and the grape together is achieved, in-situ treatment and ex-situ treatment of the breeding tail water are combined, carps in the breeding container mainly eat residues and residual feed at the bottom of the container, the content of granular nitrogen and phosphorus in total nitrogen and total phosphorus in a water body of the breeding container is reduced, and after the breeding tail water is treated by the microfilter, the content of the granular nitrogen and phosphorus in the water body is reduced. The solid substance is used as a fertilizer for grape growth in a vineyard, grape vines grow better, and duckweed in the ecological purification pond is used for feeding grass carp fries.

The invention belongs to the technical field of casting, and particularly relates to a die casting protection casting device and a using method thereof. The die casting protection casting device is connected to a ladle nozzle in a sealed mode and comprises an upper sealing assembly, a lower sealing assembly and an adjusting device, and the upper sealing assembly and the lower sealing assembly are connected in a sealed and pressed mode. The adjusting device is connected to the steel ladle casting vehicle and connected with the upper sealing assembly. A ladle nozzle and a molten steel flowing area are wrapped, non-oxidation protection in the whole casting process is achieved, and the casting blank quality is improved.

The utility model relates to the technical field of water treatment, in particular to a sewage deep nitrogen and phosphorus removal treatment device which comprises a first reaction tank, a second reaction tank, a sedimentation tank and a third reaction tank which are connected in sequence, the first reaction tank is used for carrying out denitrification treatment on the sewage, so that nitrate in the sewage is reduced into nitrogen, and the total nitrogen concentration of the sewage is reduced; the second reaction tank is used for carrying out aerobic treatment on the sewage, so that ammonia in the sewage is oxidized into nitric acid, and phosphorus, organic matters and chemical oxygen demand in the sewage are reduced; the third reaction tank is used for carrying out denitrification treatment on the sewage. The sewage treatment device has the beneficial effects that denitrification and aerobic reaction processes are optimized according to the quality of sewage, the denitrification reaction time is prolonged through the first reaction tank, organic matters in inlet water are fully utilized for denitrification nitrogen removal, and meanwhile, chemical oxygen demand and total nitrogen are removed. The second reaction tank is used for completing nitration reaction and further reducing the chemical oxygen demand of the sewage.

The application discloses a kind of deep denitrification continuous flow aerobic granular sludge reactors and control method thereof, belong to wastewater treatment field.Reactor includes the anaerobic pool, aeration tank, anoxic tank, sludge separator and secondary sedimentation tank connected in sequence, and also includes intelligent control system.Control method includes: real-time monitoring state variable;According to the deviation of state variable and preset target value, the control input of last time and control barrier function, build performance function;Approximate long-term cost function using fractional kernel function;Calculate update error and update weight coefficient;Solve optimization problem to obtain control input;Execute control instruction.The application carries out intelligent optimization and closed-loop control to key operating parameters by safety reinforcement learning algorithm, maintains stable treatment effect when influent quality and quantity fluctuate, realizes efficient, stable, self-adapting deep denitrification operation, and has strong impact load capacity.

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.