The Polyacrylamide can work as the flocculant in the sewage treatment and the waste water treatment, such as the municipal sewage, the paper making waste water, the oil refining waste water, the textile waste water, the printing and dyeing waste water, the mechanical manufacturing waste water, the leather processing waste water and the metallurgy waste water etc.

The Polyacrylamide can also be used for:

- the treatment of the raw water, including the processes as the settlement, the clarification, the sludge sedimentation and the filter backwash sludge dehydration etc,

- the industrial solid-liquid separation,

- the chemical industry, such as the pigment and the leaching solution,

- the paper making industry, such as the recovery of the white water,

- the foodstuff industry, such as the sugar separation,

- the bio pharmaceutical industry, such as the isolation of the mycelia,

- the washing water, the slurry flotation, the acidic saline, the alkaline saline etc.

The above mentioned applications of the polyacrylamide have been developed till now, however, along with the further development in future, more and more applications for the polyacrylamide to be worked as the flocculant will be developed.

The posterior flocculation to remove the sludge in the petrochemical wastewater

In the treatment of the petrochemical wastewater, the flocculation method includes the anterior pretreatment of the flocculating sedimentation and the posterior flocculation. The pretreatment can remove most of the impurities from the water, while the posterior flocculation can make the water meet the quality requirements.

The cationic flocculant is suitable for the treatment of the oily wastewater. In the past, the anionic flocculant and the nonionic flocculant was used for the treatment, but in the recent years, the cationic flocculant has been put into use for the treatment of the waste water with more suspending particles and for the sludge dewatering process, however, the cationic flocculant is not so appropriate to treat the petrochemical waste water and the wast water from the oil plants. In order to solve all sorts of the problems, the application of the organic high polymer flocculant is required.

Under the situation of different types for many application models, how to determine the matching model correctly needs the specialized technical personnel to do the job. The posterior flocculation which is discussed here, just like the name described, is the flocculation method for the sludge sedimentation when the overall treatment process is to be completed. To add the flocculant in the secondary stage in the water treatment can achieve the adsorption effect to the COD and the soluble oil in the water, thus, it can help to remove the COD in the water by 15% ~ 25%. Such minor treatment can efficiently reduce the COD, and eventually make the water meet the effluent discharge standards.