Overview

Generally, wastewater treatment methods include physical, chemical, physical-chemical and biological methods.The above several oil extraction wastewater treatment methods have their own advantages in technology and economy. Some methods can efficiently treat macromolecular pollutants, and some methods can efficiently treat refractory organic pollutants; but some treatment methods are not deep enough, and the treatment cost is high. Therefore, in the process of oil extraction wastewater treatment, the oilfield should fully consider the water quality and actual situation of the oilfield's own wastewater, and select the best treatment method in a targeted manner. By combining the oil extraction wastewater treatment methods, the effect of wastewater treatment can be greatly improved.

Physical processing

There are two main methods for physical treatment of oil production wastewater: air flotation and adsorption. Air flotation is mostly used in combination with other technologies in the actual application process. For example, the combination of air flotation and flocculation can achieve better oil removal effect. The adsorption method mainly uses some materials with relatively large surface area to adsorb the macromolecules or organic pollutants in the oil production wastewater.

Chemical treatment

Chemical methods mainly include chemical coagulation, electrolysis and chemical oxidation. Chemical coagulation is a method mainly used for the treatment of chemical agents. In general, the chemical flocculation method uses the copolymer formed by acrylamide and acrylic acid for chemical treatment, and also uses some biological flocculants and demulsifiers as auxiliary treatment agents. The main use of the electrolysis method is to apply a direct current to the oil production wastewater, so that the cathode and anode formed by the direct current power supply undergo a redox reaction to degrade some organic substances or toxic organisms, thereby inhibiting the further conversion of organic pollutants into biochemical substances. Electrolysis can remove emulsified oil and some organic substances with higher molecular weight in oil recovery wastewater. Chemical oxidation mainly includes ozone oxidation, molecular oxidation and catalytic oxidation.

Physical chemical treatment

The most widely used physical and chemical method is the electrolytic air flotation method, which is mainly to combine the electrolytic air flotation method to form a new wastewater treatment method when using the air flotation method for wastewater treatment. Float, flocculation and electrolysis are combined to form flocculation electrolysis air flotation.

Biological treatment

Biological treatment methods mainly include aerobic biological method, anaerobic biological method and biological enhancement technology. In the practical application of aerobic biological methods, activated sludge method and biofilm method are widely used. The anaerobic biological method mainly refers to the hydrolysis or fermentation of some polycyclic aromatic hydrocarbon organic pollutants that are difficult to degrade in the process of oil extraction wastewater treatment, so that the simple result organic matter can be easily further carried out. degradation. The bio-augmentation technology is mainly a temporary method to poison the microorganisms or inhibit the growth of some microorganisms in the oil extraction wastewater, and then the dominant fungi that are cultivated in the experiment will be rapidly degraded.