Wastewater Treatment Equipment for Reuse of Feclaimed Water

Product Description

The utilization of reclaimed water reuse equipment has become an effective way for many iron and steel companies to reduce the amount of new water taken and reduce the amount of water consumed in production. A good reclaimed water treatment system is inseparable from a set of suitable technology and cost-effective wastewater treatment equipment. The following will briefly introduce the following reclaimed water reuse and reclaimed water reuse equipment in the iron and steel industry.
 1. Introduction to Wastewater in the Iron and Steel Industry
   The iron and steel industry is one of the five major water-consuming industries. Wastewater comes from the water used in the production process, equipment and product cooling water, equipment and site cleaning water, etc. Wastewater contains production raw materials, intermediate products and products lost with water, as well as pollutants generated during the production process. Among them, the main pollutants of raw material plant wastewater and sintering process wastewater are SS and a small amount of heavy metal ions; iron-making and steel-making production wastewater mainly contains sS, but also a small amount of cyanide, phenols, grease, iron oxide scale, etc.; steel rolling production wastewater contains Ss , Iron oxide scale, heavy metal ions, etc. and high-salt wastewater from self-supplied power plants.
Therefore, reclaimed water reuse equipment can save water resources, improve water reuse, reduce the consumption of conventional Yangtze River water sources, reduce the consumption of new water per ton of steel, and achieve a win-win situation for economic and environmental benefits.
 2. Membrane separation and reuse technology
Membrane treatment technology is an effective sewage separation and reclaimed water reuse technology, which is widely used in various sewage treatment fields. Mainly include: ultrafiltration membrane technology, reverse osmosis, etc. At present, the most common applications of membrane technology in industrial wastewater treatment and reuse are microfiltration, ultrafiltration, reverse osmosis and combined processes. All three use external pressure differences as the driving force to separate and classify solutes and solvents in the solution. , Purification and enrichment.
 (1) Ultrafiltration
   There are many types of steel cold-rolling wastewater and the pollutant composition is complex. The use of membrane separation method can effectively remove the oil and suspended matter in the steel-rolling wastewater and reduce the load of the lower-level wastewater treatment unit.
   Ultrafiltration can effectively remove suspended solids, colloids and microorganisms in wastewater, and has a good turbidity removal effect. Usually microfiltration or ultrafiltration is used to replace the secondary sedimentation tank to intercept the suspended solids, colloids and other pollutants contained in the iron and steel wastewater. At the same time, ultrafiltration has also become the first choice as a pretreatment of reverse osmosis.
 (2) Reverse osmosis
   Reverse osmosis benefits from its unique separation mechanism, good retention of inorganic salts and high desalination rate. The effluent of reverse osmosis equipment can reach the standard for reuse. Reverse osmosis has a high desalination rate for reclaimed water. At the same time, it also has excellent removal performance for COD, BOD, bacteria, nitrogen-containing compounds, chlorides and phosphorus.
 (3) Combined double membrane method
   At present, in the treatment of reclaimed water, the pretreatment process with reverse osmosis as the main process and "multimedia + ultrafiltration" as the core is a combined process for complex raw water quality, supplemented by necessary pre-treatment units. Become the first choice of many steel companies. As the main body of desalination, reverse osmosis equipment greatly reduces the salt content of the effluent and ensures that the effluent quality of the entire system meets the reuse standard.
 3. Reclaimed water reuse equipment
   The selection of reclaimed water reuse equipment depends on the choice of treatment process. The main system of ultrafiltration reuse equipment includes raw water lifting pump, security filter, booster pump, membrane module, backwash pump, dosing pump, backwash water tank, fan, monitoring instrument and control instrument. Among them, the membrane module is the key part. After a period of operation, a filter cake layer is formed on the surface of the membrane, which leads to a decrease in the recovery rate and requires regular backwashing.
   The reverse osmosis pure water equipment mainly consists of seven parts: security filter, high pressure pump, booster pump, reverse osmosis membrane group, cleaning system, monitoring instrument and control instrument. The reclaimed water reuse equipment needs to be chemically cleaned according to changes in the recovery rate, desalination rate, etc., to restore the membrane flux and increase the service life of the reverse osmosis membrane.