company news about Production wastewater treatment and reuse in the steel plant

Production wastewater treatment and reuse in the steel plant

As is known to all, China is a major steel producer, ranking the output in the world. Although the industry has brought substantial improvement to the economy, it also derived the problem of environmental pollution, and the difficulty of industrial sewage treatment is greatly increased. The sewage produced by iron and steel enterprises is closely related to their process production. Sewage will be produced in many links of steel production, such as demineralized water produced by circulating cooling system, softening water, or thick salt water produced in the process of preparing pure water. In general, the industrial sewage produced by steel has the characteristics of neutral pH, high salt content and low COD/BOD value.

If you want to do a good job in industrial wastewater treatment, it is first necessary to understand what harmful components in the sewage?

01 Hazard analysis of production wastewater

Inorganic suspension materials are the main pollutants in the wastewater of steel plant. In all links of steel plant production, there will be inorganic suspension substances, which mainly include coal, biological sludge and metal oxides. Besides coking wastewater, inorganic levproduced in other processes are mostly non-toxic. However, the existence of these inorganic suspended objects can reduce the conduction efficiency of oxygen in the water, which can then result in hypoxia, water quality discoloration and even deterioration of water quality.

Heavy metals are also the major pollutants in steel plant wastewater. In the steel plant wastewater, the main heavy metals include aluminum, copper, cadmium, chromium, zinc, etc. Because these heavy metals can not be biodegradable in water, so under the water of various glue or particulate material adsorption, these heavy metals will deposit in the mud, and then with the help of biological chain accumulation, finally after biological circulation is absorbed into animals and human body, and then cause serious harm to animals and human health.

The harm of oil and oil In the production wastewater of steel plants, oil and oil also belong to the major pollutants. Usually, oil and oil is not harmful, but when the oil and oil discharge into the water, they will be in the form of film on the water surface, let the conduction of oxygen in the water to reduce, and then cause water hypoxia, water surface will change color because of hypoxia, serious cases will even cause water quality deterioration, smelly, cause great harm to the living environment of water organisms.

Usually, sulfuric acid and hydrochloric acid will be used for surface treatment, and these waste water is directly discharged, will also cause great harm to the environment. Due to lower pH and higher salinity, these wastewater have relatively serious adverse effects on water, soil and biology.

The harm of organic matter in the steel plant production of sewage, there will also be a lot of organic pollutants, such as toluene, benzene, phenol, naphthalene and other substances. When the waste gas treatment is conducted by using the wet flue gas purification treatment process, the organic matter in the waste gas will remain in the waste water. This waste water is very polluting and harmful, so it must be properly treated.

02 Industrial sewage treatment and reuse in the iron and steel industry

To solve the complexity of steel sewage requires the use of a reasonable process. The industrial sewage treatment system in the steel industry should include the initial sink tank, regulation tank, chemical reaction tank, micro-filter tank and several major treatment units of membrane treatment.

The main role of the primary sedimentation tank is to regulate the water intake and water quality, through which it can remove most of the suspended objects in the sewage, and a small amount of high-priced ion precipitation. If the iron and steel enterprises stop production period, the initial sink and regulation tank can play a role in regulating the sewage water volume, creating conditions for the continuity and stable operation of the system.

After the initial sedimentation tank and the regulation tank, the next oxidation reaction tank has multiple sewage treatment units, including the neutralization reaction device, oxidation reaction device and flocculation reaction device. The industrial wastewater can remove most of the organic matter and reducing material here, and then enter the subsequent secondary sedimentation tank for sedimentation separation, mainly to remove the sedimentation material produced in the previous reaction process.

Next is the depth treatment into the filtration system, where most of the suspension and colloidal impurities can be removed to meet the water intake requirements of the osmosis treatment device. However, the acid will be adjusted before this, so that the value can be stable between 6.5 and 7, and the scale retardant agent is added to prevent the production of scale.

In the final stage of sewage treatment, the sewage enters into the reverse osmosis system through the water pump, removing organic matter, microorganisms and subtle suspended particles, so as to realize the purification of sewage and meet the requirements of reuse and discharge.

03 Conclusion

To sum up, for today's steel production wastewater, good treatment and reuse is the key to ensure the rational use of water resources, save production costs and protect the environment. Therefore, iron and steel enterprises should intensify efforts to research on wastewater treatment reuse, and wastewater treatment and reuse process, so as to effectively avoid water waste, and play a good environmental protection, protect the economic interests of iron and steel plants on the basis of realize the sustainable development of resources and the environment.