What kind of polyacrylamide is used for oilfield wastewater treatment?
Municipal sewage using polyacrylamide is generally the latter stage of biochemical sludge treatment process, adding polyacrylamide sludge into the filter press for pressure filtration, so as to form mud cake.
Applicable dehydration equipment
Belt filter press, plate and frame filter press, centrifuge...
Solid polyacrylamide per ton of dry mud consumption is generally 3-6 kg, emulsion polyacrylamide in 5-10 kg. The specific amount of dry mud per ton should be determined according to beaker test, on-machine medium test or periodic operation test. The mud quality of each factory is different, and the drug consumption varies greatly with different sludge, different agents, different equipment and different management levels.
Petrochemical wastewater treatment is to produce ethylene, propylene, butene and other chemical raw materials by pyrolysis of by-product gas produced by oil refining and light oil or heavy oil such as naphtha as raw materials, further reaction synthesis of various organic chemical products, constitute the sewage discharged by petrochemical joint enterprises for treatment.
Synthetic rubber and synthetic products such as plastic, fiber, detergent and benzene, naphthalene, methanol, glycerin, acetaldehyde and other chemical raw materials, production process to remove the sewage containing raw materials and products, by-products and its high content of organic matter and sends out a bad smell, the need for precipitation, biochemical treatment or ozonation treatment, activated carbon adsorption process, etc. Tertiary treated effluent can meet higher environmental health standards or be reused in production.
At present, the development trend of petrochemical wastewater treatment technology can be summarized in three sentences: strengthening pretreatment, improving secondary treatment, supporting post-treatment.
Chemical method for petroleum wastewater treatment
Neutralization: the neutralization method, is to use a certain means of adjusting the PH value of wastewater containing acid or alkaline, to assume the neutral reaction method, and some of the oil chemical plant production equipment and ancillary facilities, often discharge wastewater containing acid, alkali, such as oil washing water, drainage, chemical facilities of tank washing water, boiler water treatment and alkali pump drainage, etc. Under normal circumstances, the PH value of alkaline wastewater is between 11 and 12, and the PH value of acidic wastewater is 1-2. When using the drug neutralization method, appropriate acid and alkali agents should be added. Limestone, calcium carbide, NACO3 and other agents are commonly used to treat acidic wastewater. When limestone or stone slag is speculated, a large amount of sludge is produced. Industrial sulfuric acid, hydrochloric acid and nitric acid are needed to treat alkaline wastewater. It is more economical to use waste acid as neutralizing agent.
2. Coagulation: in water treatment, dosing coagulant to the water to destroy the stability of the colloidal particles in water state, under the condition of a certain hydraulic, through between colloidal particles and other particles collide with each other and gathered themselves together, and to form easy separation from the water floc, such as oil, flow, arsenic, cadmium, surface active substances, radioactive substances, such as plankton and algae. Coagulants can be divided into coagulants and coagulant AIDS. Coagulants include two types, one is inorganic salts, such as polyaluminum chloride, polyaluminum ferric chloride two is a polymer flocculant, such as polyacrylamide; Coagulant aid includes three types, one is acid and alkali, such as limestone, etc., the second is flocculating core, such as silica, activated carbon, all kinds of clay, precipitation sludge, etc., the third is oxidizing agent, such as chlorine, ozone, etc. The selection of coagulants, coagulants and other agents should be based on the process test of the treated water or on the operation experience of similar treated water.
3. Oxidation: at present, in the treatment of petroleum wastewater, air oxidation method is often used for the pretreatment of sulfur nap, and ozone oxidation method is used for the three-level treatment of discharge water, to ensure that the discharge water meets the standard.