Method for pretreatment on industrial wastewater by nascent state ferrous iron reduction

Abstract

The invention belongs to the technical field of environmental protection and especially relates to a method for pretreatment on industrial wastewater by nascent state ferrous iron reduction. The method is characterized in that acidic wastewater and zero-valent iron undergo a reaction in the presence of a catalyst to produce a large amount of high-activity nascent state ferrous iron and the acidity of the acidic wastewater is eliminated and a pH value of the acidic wastewater is improved; the high-activity nascent state ferrous iron and alkaline wastewater are mixed according to a certain ratio so that nascent state ferrous iron ions form a high-activity structural-state ferrous complex under alkaline conditions; through negative and positive ions and the catalyst in the wastewater, reduction performances of structural-state ferrous iron are improved; and through addition of a trace amount of an oxidizing agent, catalytic oxidation effects of residual ferrous iron are performed so that a ferrous iron structural form is changed and coagulating precipitation effects of ferrous iron are improved. The method realizes preparation of nascent state ferrous iron from acidic waste water, utilizes reduction effects of zero-valent iron and ferrous iron, realizes synchronous treatment on acidic wastewater and alkaline wastewater, realizes treatment of wastes with processes of wastes against one another and saves a treatment cost.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a wastewater treatment method. Background technique [0002] Refractory industrial wastewater has become a difficult problem in water pollution control in my country due to its complex composition, toxic and harmful pollutants, and poor biochemical properties. The treatment of toxic and refractory industrial wastewater has also been established as a key research topic in China in the future. Due to the simple process and low cost of the biological method, the current water treatment process in my country is still dominated by the biological method, but for the increasing types of refractory industrial wastewater, due to poor biodegradability, traditional biological treatment technology is difficult to solve. Generally, pretreatment methods need to be added, and a composite process of physical and chemical pretreatment followed by biological treatment...

AI Technical Summary

Problems solved by technology

Some chemical wastewater is often strongly acidic and difficult to treat.

At present, the conventional method of treating acid wastewater is to use the "lime neutralization method", which is widely used because of the low price of lime; however, there are many problems in the lime method, such as high calcium content, which is easy to scale in the pipeline and form sediments , blockage of pipelines, less and less used in actual projects, and the addition of a large amount of alkaline substances such as lime increases the processing cost

The Chinese patent "A Treatment Method for Industrial Acidic Wastewater" (CN101891294A) discloses the use of strong alkaline industrial waste barium slag to treat acidic industrial wastewater. Disadvantages of often containing a large amount of toxic substances

The Chinese patent "Treatment Process and Equipment for Acid-Alkaline Wastewater" (CN19511839A) mentions adding alkaline actual wastewater to neutralize acidic wastewater to adjust the pH of the mixed solution, flocculation and sedimentation, but the effect of adjusting the alkalinity of alkaline wastewater is poor, or requires a lot of Ratio of alkaline wastewater dosing

However, the suitable pH of the iron-carbon internal electrolysis method is 3 to 5, and there are application problems such as easy clogging and material hardening, and due to the use of oxygenation methods such as aeration, the large amount of ferrous iron produced cannot be fully utilized.

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