Demulsifier is a water-soluble water treatment agent, can be mutually soluble with water in any proportion, has strong demulsification and flocculation effect, for oil in water, oil bubble water emulsion wastewater, can achieve rapid demulsification and flocculation, COD removal, oil removal and other effects, often with belt filter press, plate and frame filter press, centrifuge and so on.
Dosage varies with the concentration of sewage. Generally, dosage is about 1/1000 (0.5 kg demulsifier for wastewater treatment is added to 1 ton of water).
First, in the treatment of petroleum wastewater, wastewater demulsifier is generally added into the water before the air flotation process to destroy the stable state of colloidal particles in the water.
Under certain hydraulic conditions, flocs that are easy to be separated from the water are formed through the collision and aggregation between colloidal particles and other particles. Such as oil, sulfur, arsenic, cadmium, surface active substances, radioactive substances, plankton and algae, etc.
The agents in the coagulation process can be divided into demulsifier for petroleum wastewater treatment and flocculant for petroleum wastewater treatment.
Petrochemical industry is based on petroleum as raw material, reforming and synthetic refining process based on a series of organic processing process, petrochemical product production process is long, production device, produced wastewater water volume, typical petrochemical wastewater contains petroleum, CODCr, ammonia nitrogen, sulfur, phenol, synthetic compounds and other conventional pollutants. Produced sewage also contains a variety of organic chemical products with related characteristics of pollutants, such as polycyclic aromatic compounds, aromatic amine compounds, heterocyclic compounds and so on, resulting in the sewage water quality not only complex, petroleum chemical wastewater with high oil and difficult biochemical characteristics, can try to use oil demulsifier wastewater difficult to adjust.
Oil wastewater demulsifier is specially designed for oily wastewater and has higher treatment capacity for oily wastewater, making its supernatant clear and reducing COD;
Second, polymer flocculants, such as polyacrylamide, after the agents involved in waste water by flotation using highly fragmented tiny bubbles adhered to as a carrier of suspended solids in the wastewater, make its be separated with bubbles rise to the surface, floc pressure through the filter press mud treatment, while the treated waste water again after the biochemical or other process, etc.
Oil wastewater demulsifier is a high polymer, which can separate and precipitate emulsified oil and colloid in water. In the water can absorb electricity and at the same time, remove COD, chroma, total phosphorus, SS, ammonia nitrogen, heavy metals in the water, mainly by partially replacing the role of the stable film to destroy the emulsion, used as a dehydrating agent, can take off the water in the crude oil and heavy oil, so that the water content meets the requirements.
Its principle is adding demulsifier, through to the waste water in the waste water suspended solids to form flocculate coalescence, this process can not only remove suspended solids in waste water and colloid particles, reduce the COD value, and also can remove bacteria and so on, is to point to in under the action of flocculant, colloid and fine suspended solids in the oil field waste water to electrostatic neutralization and adsorption or bridge.
Finally, the generated flocs are removed, and chemical flocculation is widely used as a pretreatment technology in major oil fields, often combined with gas flotation.
Due to petroleum wastewater is complex mixture of liquid and its main components are water soluble gas, solid, crude oil, suspended solids, electrolyte, bacteria and a variety of materials such as oilfield chemical additives, if direct emissions, not only will cause serious harm to the environment, pollution of surface water and farmland, causing the death of plants and animals and human potential disease, Therefore, more and more petroleum industry began to pay attention to wastewater treatment, and the use of demulsifier for petroleum wastewater also increased day by day.