Preparation method of magnetic nanometer water treatment agent for oil field sewage

Abstract

The invention discloses a preparation method of a magnetic nanometer water treatment agent for oil field sewage. The preparation method includes firstly, soaking magnetic nanometer particles of Fe3O4 with water while regulating pH to 5-7 and then carrying out ultrasonic dispersion to obtain an aqueous solution containing magnetic nanometer particles of Fe3O4; stirring the aqueous solution containing magnetic nanometer particles of Fe3O4 in a container, placing the container in constant-temperature water bath for holding temperature, gradually dropwise adding sodium oleate solution, after that, continuing to stir for 20 to 40 minutes, and cooling the solution to the temperature of 45 to 55 DEG C to obtain a mixture; finally, adding block polyether modifier solution in the mixture while stirring at the temperature of 45-55 DEG C for 0.5 to 2 hours so as to obtain the magnetic nanometer water treatment agent. The water treatment agent has the advantages such as flocculation, demulsification and easiness in magnetic separation. The water treatment agent can be recovered so that consumption of the water treatment agent is lowered and water treatment cost is reduced.

Description

technical field [0001] The invention relates to the technical field of recovery and treatment of oilfield sewage, in particular to a preparation method of a magnetic nanometer water treatment agent used for oilfield sewage. Background technique [0002] Oilfield sewage includes waste drilling fluid, oilfield operation sewage, oilfield produced water, fracturing flowback fluid and other oily sewage. Except for a small amount of crude oil, these sewage generally contain suspended solids, polymers, emulsifiers, etc. These substances will enhance the stability of the oil-in-water emulsion in the sewage, so it is difficult to purify. At present, the gas suspension method and gravity separation method in oil removal technology can only remove large suspended oil and dispersed oil; while the membrane separation method has the disadvantages of high energy consumption, small processing capacity, and short membrane life. Adding chemical agents such as flocculants to remove oil is the...

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Problems solved by technology

Patent CN201510408911.2 discloses a method of preparing surface-functionalized ferroferric oxide magnetic microspheres by polymerizing with acrylamide monomers, cationic monomers containing quaternary ammonium bases, and anionic monomers containing sulfonic acid groups or carboxyl groups. The core-shell magnetic water treatment agent with a particle size of 350-450nm can be used to reduce the content of inorganic salts in oilfield sewage, but the degreasing effect is unknown; patent CN201410339063.X discloses a compound of 100-200 mesh iron powder and conventional flocculants The preparation method of the enhanced coagulant obtained with the combination of the magnetic separation device can speed up the precipitation of the flocs, and the dosage of the agent is 150Kg / m 3 The crude oil content in the sewage can be reduced to 50mg / L, but its formula composition is relatively complicated, and the dosage of the agent is too large; patent CN201410370352.6 discloses a preparation method of composite magnetic micro-nano particles modified on the surface of amino acid, and the oil removal rate is in About 90%, due to the low reactivity of amino acids, the modification degree of magnetic nanoparticles is only below 75%, which affects the improvement of oil removal rate; patent CN201310281632.5 discloses a magnetic nanoparticle with a particle size of 10-20nm. Oil-removing water purifier, the oil-removing rate can reach about 95%, but the preparation method and related implementation methods of the complete particles are not disclosed

Patent CN200810236222.8 discloses a water treatment agent prepared by coating the conventional water treatment agent polyaluminum chloride on the surface of 2.5nm magnetic nanoparticles, but the preparation is relatively complicated, and the specific applicable water treatment environment is not introduced. The degreasing effect of oilfield sewage is unknown; patent CN201410230243.4 discloses a compound of conventional flocculant and magnetic nanoparticles to remove anionic polyacrylamide in tertiary oil recovery sewage, but the magnetic nanoparticles have not been surface-modified, For enhanced floc separation only, oil removal effect is unknown