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Printing and dyeing wastewater treatment equipment
Basic equipment configuration:
Name: Printing and dyeing wastewater treatment equipment
Sewage treatment capacity: 100-500 (m3 / h)
Ozone dosage: 100 (g / h)
Air volume: 200 (m3 / min)
Air tank capacity: 100 (m3)
Flowmeter specifications: 1-10 (m3 / h)
Outlet pipe diameter: 80 (mm)
Inlet pipe diameter: 80 (mm)
Dimensions: 1500 * 80 * 1010 (cm)
Aerator power: 0.37 (kw)
The water quality of printing and dyeing wastewater is complex. Pollutants can be divided into two categories according to their source: one is the entrainment from the fiber material itself; the other is the slurry, oil, dye, and chemical additives used in the processing. Analysis of the characteristics of its wastewater mainly includes the following aspects.
1. Large amount of water, high content of organic pollutants, deep chroma, large changes in alkalinity and pH, and drastic changes in water quality. Due to the development of chemical fiber fabrics and the improvement of finishing technology after printing and dyeing, a large amount of organic matter that is difficult to biochemically degrade, such as PVA slurry and new additives, has entered the printing and dyeing wastewater, which has increased the difficulty of treatment.
2.Due to the dyeing and finishing requirements of different dyes, different auxiliaries, and different fabrics, the pH value, CODCr, BOD5, color, etc. in the wastewater are also different, but their common feature is that the BOD5 / CODCr values are very low, generally At about 20%, biodegradability is poor, so measures need to be taken to increase the BOD5 / CODCr value to about 30% or higher to facilitate biochemical treatment.
3. Alkali-reducing wastewater in printing and dyeing wastewater may have a CODCr value of more than 100,000 mg / L and a pH value of ≥12. Therefore, it is necessary to perform pretreatment, recover alkali, and add acid to lower the pH value. After the treatment meets certain requirements, it enters the adjustment tank and is processed together with other printing and dyeing wastewater.
4. Another feature of printing and dyeing wastewater is high chroma, some of which can be more than 4,000 times. Therefore, one of the important tasks for the treatment of printing and dyeing wastewater is to perform decolorization treatment. To this end, research and selection of efficient decolorizing bacteria, efficient decolorizing coagulants, and treatment processes that are beneficial to decolorization are required.
5. In the printing and dyeing industry, the use of PVA slurry and new additives has increased the content of organic compounds that are difficult to biodegrade in wastewater. In particular, the proportion of CODCr content caused by PVA slurry in the total CODCr of printing and dyeing wastewater is quite large, and ordinary microorganisms used for water treatment are difficult to degrade this part of CODCr. Therefore, research and screening of microorganisms used to degrade PVA is needed.
In addition, due to the intermittent operation of production, there is a fluctuation in water quantity and quality; for wastewater using a large amount of reducing dyes, sulfur dyes, ice dyes, etc., its chemical flocculation effect is relatively poor. Therefore, the treatment process must consider these factors and have a certain ability to adapt to changes in water volume and water quality load.
Methods for the treatment of printing and dyeing wastewater include physicochemical methods, biochemical methods, chemical methods (multifunctional coagulant treatment method, high-voltage pulse electrolysis method), etc., but most of them are combined biochemical-physical-chemical methods with biochemical as the main body.
The water quality of printing and dyeing wastewater varies with the type of fiber and processing technology used, and the composition of pollutants varies widely. Printing and dyeing wastewater is generally characterized by high concentrations of pollutants, many types, toxic and harmful components, and high chroma. Generally, the pH value of printing and dyeing wastewater is 6 ~ 10, CODCr is 400 ~ 1000mg / L, BOD5 is 100 ~ 400mg / L, SS is 100 ~ 200mg / L, and chroma is 100 ~ 400 times.
But when the printing and dyeing process, the type of fiber used and the processing process are changed, the quality of sewage water will change greatly. In recent years, due to the development of chemical fiber fabrics, the rise of artificial silk and the improvement of printing and dyeing finishing technology, it has made PVA pulp, rayon alkali hydrolysates (mainly phthalic acids), new auxiliaries and other difficult-to-biodegrade organic substances When a large amount of wastewater enters the printing and dyeing industry, its CODCr concentration also rises from a few hundred mg / L to more than 2000 ~ 3000mg / L, BOD5 increases to more than 800mg / L, and the pH value reaches 11.5 ~ 12, thus making the original biological treatment system The CODCr removal rate decreased from 70% to 50% or even lower.
主要针对印染污水高色度难以脱色，高COD难以降低设计研发，可有效解决以往印染废水处理过程中的技术难点是印染废水经处理后可达标排放。 Printing and dyeing wastewater treatment equipment is mainly aimed at printing and dyeing wastewater with high chromaticity and difficult to decolorize, and high COD is difficult to reduce design and research and development.
Our company is a professional manufacturer of printing and dyeing wastewater treatment equipment. The following introduces the treatment technology of printing and dyeing wastewater treatment equipment.
Biochemical method: The biochemical method has low operating cost and is most widely used in wastewater treatment. However, to solve the two major treatment difficulties of printing and dyeing wastewater, further research is needed on the process. The main research directions are: cultivating some highly efficient and specialized bacteria, such as efficient decoloring bacteria and PVA degrading bacteria, etc .; studying new anaerobic-aerobic biological treatment processes.
Membrane separation technology: Membrane separation technology for printing and dyeing wastewater treatment has the characteristics of low energy consumption, simple process and no pollution to the environment. It is increasingly used in wastewater treatment and reuse. There have been many studies at home and abroad. The main development point of membrane separation technology should be the development of new membranes and new membrane processing equipment or processes.
Photocatalytic oxidation method: The photocatalytic oxidation method has obvious energy saving, high efficiency, and thorough degradation of pollutants. Commonly used catalysts include inorganic reagents such as titanium dioxide, hydrogen peroxide, and iron oxalate. The application of photocatalytic oxidation technology in the field of wastewater treatment has good market prospects and economic benefits, but there are still many problems in research in this area, such as the search for more efficient catalysts, low energy and efficient energy sources, catalyst separation and recovery, reaction mechanisms and Kinetics need further study.
Other methods: In the treatment of refractory printing and dyeing wastewater, supercritical water oxidation technology (SCWO), low-temperature plasma chemical method, and ultrasonic degradation technology are also new technologies that are currently active in research. In addition, foreign countries have made considerable progress in the research of ozone-ultraviolet method, ozone-infrared method, ozone-biochemical method, wet air oxidation method, extraction method, and C-ray radiation method. Among them, the C-ray radiation method can strengthen subsequent coagulation. The treatment effect greatly improves the removal rate of cationic dyes. It is also an important method to treat printing and dyeing wastewater abroad for high-concentration, high-salt-content dye waste liquids and mother liquors that are evaporated and concentrated and then burned (add auxiliary fuel if necessary).
Advantages of printing and dyeing wastewater treatment equipment
1. Printing and dyeing wastewater treatment equipment is made of carbon steel anti-corrosion treatment or using stainless steel components, assembled on site, light weight, easy to transport, and easy to install;
2. It adopts FRP, carbon steel, stainless steel anti-corrosion structure, which has excellent characteristics such as corrosion resistance and aging resistance, with a service life of more than 20 years;
3. Placed below the ground, the ground above the equipment can be used for greening or other land, no need to build a house and heating and insulation. Maximize system integration and reduce floor space;
4. No pollution, no noise, no odor, reduce secondary pollution;
5. It is not limited by the amount of wastewater, and is flexible and can be used individually or in combination.
6. The silk fabric printing and dyeing wastewater treatment equipment has a PLC automatic electrical control system and equipment fault alarm system. The operation is safe and reliable. Generally, no special person is required to manage. Only the timely maintenance and maintenance of silk fabric printing and dyeing wastewater treatment equipment is required, and the management cost is small.
Industry Standard: Wastewater Discharge Standard for Printing and Dyeing Industry