Process Analysis of Betel Ink Wastewater Treatment Integrated Equipment
Ink sewage has the characteristics of high pollution concentration and difficult treatment. With the increasingly strict discharge standards, the treatment of ink wastewater is an urgent problem to be solved in today's environmental protection work. Most enterprises have done in-depth treatment of ink wastewater, strengthened the treatment of ink wastewater, made pollution treatment, and responded to the national call to gradually reduce the amount of sewage discharged, and realized the recycling of sewage, which is conducive to the establishment of wastewater. The goal of resource-saving, environmentally friendly companies.
1 Source and classification of water-based ink wastewater
Water-based inks are mainly used in books, magazines, corrugated paper and other printed materials. They are also widely used in the packaging of wineries, tobacco factories, pharmaceutical factories, cosmetics factories, children's toy factories, milk and beverage composite papers. In the production process, water-based inks will produce a certain amount of wastewater due to the cleaning of the equipment. Water-based inks can be classified into three types: alkali solubility, water solubility, and diffusion. Alkali soluble inks are currently being developed and widely used.
2 water-based ink sewage characteristics
The main pollution in water-based ink production wastewater is acrylic acid-based water-soluble resin (carrier), colored organic group-containing cyclic organic matter (colorant), and large molecular weight alcohol-based or phenyl dispersant. Acrylic resin is wastewater. The main component of CODcr, accounting for more than 80%. There are many kinds of pigments, among which inorganic pigments are salt, oxide and carbon; organic pigments include azo pigment, phthalocyanine pigment, nitro pigment, lake pigment, reducing pigment, nitroso pigment, miscellaneous Various types of ring pigments. In addition, it also contains more than ten kinds of additives such as stabilizers, defoamers, retarders, surfactants and preservatives. The water-based ink production wastewater is weakly alkaline, contains a large amount of refractory organic matter, and has high chroma and low BOD/COD ratio. It does not have direct biochemical conditions, so it is difficult to handle.
1) The content of CODcr in the ink wastewater is high, accounting for 80% of the total production wastewater CODcr. Therefore, the ink wastewater must be completely separated from the wastewater of other workshops to avoid mixing with other low-concentration wastewater, thereby increasing the ink wastewater treatment capacity.
2) The ink wastewater is alkaline, and the method of acid neutralization is adopted. The pH should be adjusted to 2~3, and a large amount of sulfuric acid needs to be added. When design, the waste acid discharged from the production line can be introduced to reduce the pH value of the ink wastewater, and the sulfuric acid is greatly reduced. The amount of waste, while at the same time managing the waste acid produced in the production process.
3) In the ink wastewater, the ratio of BOD/COD is too low (<0.2), and the biodegradability is poor. It is necessary to add organic matter rich in nitrogen and phosphorus. The design should consider introducing domestic wastewater into the plant area, so that the domestic wastewater is rich in nitrogen and phosphorus. Nutrients, in order to improve the biodegradability of ink wastewater, and reduce the cost of ink wastewater treatment, while treating domestic sewage, can be described as two-fold.
3. Process analysis of ink wastewater treatment equipment
1. The ink wastewater is removed from the large suspended solids or floating matter through the grid, and is collected into the wastewater regulating tank for collection and concentration. The wastewater is sent to the sewage treatment equipment through the lifting pump.
2. The wastewater in the ink wastewater tank is transported to the static pipeline mixer through the lift pump, and the dosing system thoroughly mixes the sewage and the medicament into the flocculation tank to fully react to form coarse and dense flocs;
3. After the flocculation tank sewage reaches a certain liquid level, it is transported to the plate and frame filter press by the diaphragm pump for solid-liquid separation. After the filter press, the sludge is concentrated and transported regularly, and the clean water flows back to the neutral tank.
4, the dosing system control agent is added to the neutralization tank by the metering pump, the pH of the sewage is automatically adjusted to 6 ~ 9;
5. When the sewage from the neutral tank reaches the high liquid level, it is sent to the carbon filter tank by centrifugal pumping, and the color is further removed by the adsorption of activated carbon, and the residual suspended matter is filtered out.
6. After the carbon filter, the effluent flows into the biochemical temporary storage pool. The biochemical storage tank flows into the hydrolysis acidification tank through the lift pump. The water in the hydrolysis acidification tank overflows into the oxygen consumption tank. The oxygen-consuming pool overflows into the MBR pool and is filtered through the MBR membrane and flows into the clear water pool. The water in the clear water tank can be directly discharged or used separately.