Printing and dyeing plant sludge treatment and polyacrylamide application

In Jiangsu and Zhejiang provinces, water treatment is the most likely one to contact with the printing and dyeing plant's wastewater. However, the disposal of sludge from printing and dyeing wastewater causes headaches for manufacturers. Generally, dye-stained sludge is high in inert materials, such as denim clothing. Wastewater produced by the sludge contains a high amount of sand, but organic matter, pathogenic bacteria, etc., have a low content, a low calorific value, and a high content of heavy metals (compared with sludge produced by municipal sewage). Since the printing and dyeing industry itself uses different raw materials, product varieties, product processing methods and other different sludge components are not the same, the use of * dyes, the content of the company is bound to be higher. Therefore, the selection and dosage of the chemicals used in the treatment of dyeing sludge should be treated differently according to the source of the sludge. The scale of sewage treatment, sludge production, pharmaceutical sources, dosage of pharmaceuticals, operating costs, mud cake moisture content and other aspects should be considered. Based on local conditions, comprehensive consideration.

At present, domestic printing and dyeing plants are limited by their scale, and the amount of waste water rarely exceeds 100,000 cubic meters per day. It is not advisable to use a large area of ​​land for natural drying or to set up incinerators, especially in Jiangsu and Zhejiang, where rains and humid climates are drying out. There is nothing in the field. Generally, some small-scale sewage treatment plants are used for treatment. Sludges are preliminarily conditioned and subjected to squeezing. In the dehydration process, a large amount of flocculants are used as sludge dewatering agents for flocculation in sludge treatment. Many agents, such as aluminum sulfate, ferric chloride, ferrous sulfate, polyaluminum chloride, polyaluminum sulfate, polyacrylamide, etc., all kinds of pharmaceutical agents have their scope of application and advantages and disadvantages. Each of the sewage treatment plants uses different chemicals in each step of printing and dyeing wastewater treatment. However, for sludge treatment, comprehensive consideration is mainly given in the following aspects:

1 Wide range of pharmaceutical sources and easy to purchase;

2 cheap price;

3pH wide application range;

4 Chemical corrosion is small;

5 flocculation effect is good and less consumption;

6 Filtrate returned to the sewage treatment system does not have a negative effect.

Therefore, our preferred agent for sludge treatment is polyaluminum chloride and polyacrylamide. Polyacrylamide is generally classified as anionic, cationic, and nonionic. The choice of what kind of polyacrylamide should be tested and screened according to the characteristics and processing methods of the sludge. However, if the polyacrylamide is used as a dehydrating agent, the dry solids content after dehydration can generally exceed 25% and can meet the transportation requirements. The manufacturers can also accept the investment, operating costs and sludge disposal methods.