Application of polyacrylamide Zetag 8190 in water treatment

An overview of polyacrylamide

Polyacrylamide referred to as PAM, commonly known as flocculant or coagulant, molecular formula is: + CH2-CHN linear polymer, molecular weight between 4-20 million, solid product appearance is white or slightly yellow powder, liquid is colorless viscous colloidal, soluble in water, easy to decompose when the temperature exceeds 120℃.

Polyacrylamide molecules with positive groups (-CONH2), and dispersed in the solution of suspended particles adsorption and bridging, has a strong flocculation, so widely used in water treatment and gold, paper making, petroleum, chemical, textile, mineral processing and other fields.

Polyacrylamide is divided into: cationic polyacrylamide, anionic polyacrylamide, non-ionic polyacrylamide, amphoteric polyacrylamide.

Two, the application of polyacrylamide in municipal sewage treatment

Municipal sewage comes from domestic sewage and industrial waste water discharged by households, institutions, businesses and urban public facilities. The amount of waste water is large and there are obvious cyclical changes of day and night and season. The main pollutants in the wastewater with animal and plant oil, suspended solids, carbohydrate, protein, surfactant, nitrogen and phosphorus compounds, such as microorganisms, the organic pollutants are usually easy to biodegradation, biochemical sex BOD/COD value is 0.5 ~ 0.6, and contains the nutrients such as nitrogen and phosphorus, as the growth of organisms provide a good environment.

For a long time, the secondary biological treatment of municipal sewage mostly adopts activated sludge process, which is the most widely used secondary biological treatment process in the world, with high treatment capacity, good effluent quality and other advantages. However, there are generally high foundation cost and operation cost, high energy consumption, complex management, easy to appear sludge bulking, sludge floating and other problems, and can not remove nitrogen, phosphorus and other inorganic nutrients. Because sewage treatment is a project focusing on environmental and social benefits, it is often limited by funds in the process of construction and actual operation, making the problem of treatment technology and funds become the "bottleneck" of water pollution treatment in China.

Three, the existing problems in municipal sewage treatment

At present, in the field of research and application of urban domestic sewage treatment, the common problems are:

(1) Using the traditional activated sludge method, usually high foundation cost, operation cost, energy consumption, complex management, easy to appear sludge bulking phenomenon; Process equipment can not meet the requirements of high efficiency and low consumption.

(2) as the sewage discharge standard is strict, nitrogen, phosphorus and other nutrients in sewage discharge demand is higher, the traditional which has the function of nitrogen and phosphorus wastewater treatment process is given priority to with activated sludge process, often require multiple anaerobic anaerobic-aerobic reaction pool in series, multistage reaction pool formation, by increasing the inner loop to achieve the purpose of nitrogen and phosphorus, This is bound to increase the cost of infrastructure investment and energy consumption, and make operation and management more complex.

(3) At present, the treatment of urban sewage is mainly centralized treatment, and the investment of the huge sewage collection system far exceeds the investment of the sewage treatment plant itself. Therefore, the construction of large-scale sewage treatment plant, centralized treatment of domestic sewage, from the point of view of sewage recycling is not necessarily the only desirable solution.