Papermaking wastewater treatment case
A paper mill in Zibo City, Shandong Province, has purchased special polyacrylamide for papermaking wastewater treatment produced by Diluo company half year ago. In a recent return visit, waste water treatment responded by the customer has been excellent and passed the acceptance standard of the Environmental Protection Department.
The papermaking wastewater from a paper mill in Zibo City, Shandong Province, mainly comes from the two production processes of pulping and papermaking. Both processes discharge large amounts of wastewater. Among them, the waste water produced by pulping has the most serious pollution.
During washing, the discharged waste water is dark brown and is called black water. The concentration of pollutants in black water is very high, and contains a lot of fibers, inorganic salts and pigments. The wastewater discharged from the bleaching process contains a large amount of acid-base substances.
The waste water discharged from the paper machine is called white water, which contains a lot of fibers and fillers and compounds added during the production process. The details of the use of our polyacrylamide product by a paper mill in Zibo City are described in detail in the following.
First, the wastewater treatment process of waste paper papermaking
1) Precipitate: Initially precipitate the sewage in the primary sedimentation tank, and use the weight of the impurities in the sewage to separate the particles or colloidal organic matter.
2) Flocculation and sedimentation: adding flocculant in the coagulation sedimentation tank to accelerate the precipitation of particles and other impurities;
3) Coagulation and sedimentation: Add high-efficiency coagulant to remove suspended solids by more than 80%;
4) Filtration: The sewage after three stages of precipitation is filtered by quartz sand and PP cotton;
5) Adsorption: Removal of impurities with smaller molecular structure using biological activated carbon;
6) Fine filtration: Filtration with hollow fibers. This kind of treatment process has the advantages of small dosage, good treatment effect and easy operation.
Second, selection and use of after-treatment medicament
The effect used in papermaking depends on its average molecular weight, ionic properties, ionic strength, and activity of other copolymers. The combination of physicochemical treatment and biochemical treatment, the general physicochemical and biochemical treatment process is wastewater → screen → adjustment → precipitation or air flotation → A/O or contact oxidation → secondary sedimentation tank → discharge, using cations Polyacrylamide in this treatment scheme.