Method for processing viscose fiber production wastewater

Abstract

The invention relates to the technical field of industrial wastewater processing, and specifically relates to a method for processing viscose fiber production wastewater. A large amount of acidic and alkaline wastewater is generated during production of viscose fiber, and severe water pollution and loss and waste of a large amount of fiber source are caused by direct discharge of the wastewater. The method for processing viscose fiber production wastewater is a technology formed by adding a processing technology combining shallow-layer air floatation and iron chip filtering on the basis of a processing technology combining a physicochemical process and a biochemical process. The beneficial effects generated by execution of the technical scheme comprise that source is utilized, cellulose in production wastewater of viscose fiber is recovered, fixed investment is reduced, production cost is reduced, and the quality of processed water can steadily reach national first-level discharge standard.

Description

technical field [0001] The invention relates to the technical field of industrial wastewater treatment, in particular to a method for treating viscose fiber production wastewater. Background technique [0002] With the rapid development of industry, the types and quantities of wastewater have increased rapidly, and the pollution of water bodies has become increasingly widespread and serious, threatening human health and safety. The output of viscose fiber accounts for about 1 / 3 of the total output of chemical fiber. The annual output of viscose fiber in my country reaches hundreds of thousands of tons, and it is the main chemical fiber variety. A large amount of acid and alkali waste water is produced in the production process of viscose fiber, and its direct discharge will cause serious water pollution and loss and waste of a large amount of fiber resources. [0003] Viscose fiber production wastewater mainly includes acidic and alkaline wastewater, of which acidic wastewa...

AI Technical Summary

Problems solved by technology

[0006] 1. After the wastewater is mixed, the acidity is still strong (pH=2~3). At this time, a large amount of viscose cellulose in the original wastewater is acid-separated, and the cellulose is small in volume and mass, and it is difficult to completely remove it by conventional precipitation methods. , thereby affecting the quality of effluent water, causing COD to exceed the standard and resource loss and waste;

[0007] 2. This process mainly removes sulfides (such as H 2 S, CS 2 etc.), but affected by many factors, the stripping efficiency is not very high, and S 2- Exceeding the standard;

[0008] 3. In the precipitation process of adding lime milk to remove zinc, due to the narrow range of the optimal pH value of the precipitation reaction (pH=8~9), the reaction conditions are difficult to control, and with the addition of manual dosing, Zn often appears in the effluent 2+ Exceeding the standard;

[0009] 4. Due to the low pH value of the mixed wastewater, a large amount of lime emulsion needs to be added to meet the subsequent precipitation reaction conditions, which increases the operating cost, and the large amount of lime residue produced increases the load of the subsequent sedimentation tank, thus It also increases the amount of sludge treatment and the difficulty of disposal in the entire treatment process

[0011] 1. Since only an activated sludge biochemical treatment process is added on the basis of physical and chemical treatment, some problems in the original physical and chemical treatment process (such as loss and waste of resources, high operating costs, and large amount of sludge) still exist;

[0012] 2. Due to the low degree of automatic control of the previous physical and chemical treatment process, the operation effect is unstable, so that SO often appears in the effluent after the primary treatment. 2-4 , Zn 2+ Exceeding the standard phenomenon, and usually when SO 2-4 >1000mg / L or Zn 2+ When >20mg / L, the growth of microorganisms will be significantly inhibited, which greatly affects the efficiency of subsequent biochemical treatment;

[0013] 3. Due to the low removal efficiency of COD in the previous physical and chemical treatment process, when a large amount of light cellulose precipitated by acid in wastewater enters the subsequent biochemical treatment of activated sludge, the pollution load is relatively large, and the quality of activated sludge is not high. Long residence time (5.7-9.5 h), which makes the entire infrastructure investment and operation costs higher, and occupies a larger area

This technical scheme only introduces a treatment method for the acid liquid produced in the viscose fiber production process, but does not realize the treatment of alkaline wastewater

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