RU2355643C1 - Method of removing oil products and mechanical impurities from water - Google Patents

Abstract

FIELD: treatment facilities.

SUBSTANCE: invention relates to the methods of splitting immiscible liquids and can be used to remove organic impurities, emulsions, surface active agents, oil products and mechanical impurities from water. The method of removing oil products and mechanical impurities from water implies splitting it into oil and water phases by electroflotation which is carried out in a device fitted with at least one electrode assembly mounted in the upper and lower parts of the installation casing; the supply of water for treatment and its splitting into oil and water phases is performed in the gap formed by the lower and upper electrode assemblies. The oil phase passed through the upper electrode assembly is collected in the upper part of the casing, cleared from the electrolysis gases and withdrawn through the outlet branch pipe for the purified oil, the water phase passed through the lower electrode assembly is withdrawn through the outlet branch pipe for the purified water; the solid fraction produced is removed through a branch pipe in the lower part of the casing.

EFFECT: method ensures improving the efficiency of the oil-containing effluent treatment.

3 cl, 1 dwg, 2 tbl, 1 ex

Description

The invention relates to methods and devices for the separation of immiscible liquids and can be used to purify water from organic impurities, emulsions, petroleum products and mechanical impurities.

A known method of purifying water from oil products and solids, including the separation of organic and aqueous phases by electroflotation without the addition of a coagulant and flocculant, see SU 1754663, 08/15/92 - prototype.

The effectiveness of the method of purification of oily wastewater to a large extent depends on the hardware design and hydraulic parameters.

The task of the invention is to develop an effective method for the purification of oily wastewater.

This goal is achieved by the fact that in the method of purifying water from oil products and mechanical impurities, including the separation of it into oil and water phases by electroflotation, the cleaning is carried out in a device equipped with at least one electrode assembly located in the upper and lower parts of the installation casing, while the water supply for purification and its separation into the oil and water phase is carried out in the space formed by the upper and lower electrode assemblies, the oil phase that has passed the upper electrode assembly is collected in the upper part of the casing, electrolysis gases are removed from it and discharged through the outlet pipe for purified oil, and the aqueous phase that has passed the lower electrode assembly is discharged through the outlet pipe for purified water, while the resulting solid fraction is removed through a pipe in the lower part of the case. Depending on the composition of petroleum products, purification is carried out with or without additives of coagulant and flocculant.

The electrode assembly contains horizontally and / or vertically arranged electrodes.

The treatment of purified water is carried out in a device containing a reaction zone 3 inside the housing 1, formed by two or more electrode assemblies 2 with vertical or horizontal electrodes located in the upper and lower parts of the reaction zone 3, where the purified water enters through the pipe 4, is saturated with electrolysis gases - oxygen and hydrogen and is stratified into a light fraction - oil and heavy - water moving in different directions (see drawing). Oil rises, passes through the upper electrode assembly, is cleaned of impurities and is collected in the upper part of the housing. Electrolysis gases are removed from the oil to the atmosphere through the pipe 5, clean oil is removed from the housing through the oil output pipe 6. The water fraction moves down, passes the lower electrode assembly, is purified from soluble impurities and solid particles and is discharged through the purified water output pipe 7, the solid fraction removed through the pipe 8 in the lower part of the housing.

Depending on the composition of the petroleum waste water, its purification by the proposed method is carried out with or without additives of coagulant and flocculant. As reagents use lime, salts of ammonium, iron, polyacrylamide, etc.

The present invention solves the creation and industrial implementation of a high-performance method for treating wastewater containing organic substances, emulsions, oil products, surfactants and mechanical impurities.

Example.

The continuous laboratory electrolyzer for the purification of oily wastewater is made of organic glass with bottom 1 and top 2 mesh horizontal electrode assemblies made of stainless steel 1X18H9T.

The parameters of the electrolyzer: d = 80 mm, H = 240 mm, Vob = 1.2 l, Vrab. = 1.0 l, assembly No. 1 consists of 3A and 2K, assembly No. 2 consists of 1A and 1K, the dimensions of the electrodes are d = 70 mm, r = 35 mm, S _{1 el-da} = 38.465 cm ² , T = 2 mm, ER = 10 mm. Designations: d — diameter, H — height, V — volume, A — anode, K — cathode, r-radius, S — surface area, T — thickness, ER — interelectrode distance.

An electrolysis method has been tested in a laboratory setup for the treatment of wastewater from gas stations containing petroleum waste. The experiments were carried out at a temperature of 21.5 ° C, the consumption of coagulant of aluminum sulfate 80.0 mg / l, flocculant polyacrylamide - 0.05 mg / l. The results of the experiments are presented in Table 1, 2.

Table 1 Electrolysis parameters. Electrode assembly Voltage Current strength, mA Bulk current density, A / l Productivity, l / hour No. 1 3.8 125 No. 1 + 2 3.3 200 0.2 5.4

table 2 Process characteristics. Indicators Water The cleaning efficiency,% source peeled water pH 6.83 7.09 Suspended Substances, mg / L 1030 thirty 97.1 Oil products, mg / l 120 0.04 99.9

Water purification indices were determined by standard methods. To analyze the content of petroleum products, the IR spectrophotometry method was used. The productivity of the apparatus was determined by the yield of purified water per unit time (ml / min, l / h).

The experimental data (Tables 1, 2) show the high efficiency of purification of oily wastewater by the electrochemical method described in the invention.

Claims (3)

1. The method of purification of water from petroleum products and solids, comprising separating it into oil and water phases by electroflotation, characterized in that the purification is carried out in a device equipped with at least one electrode assembly located in the upper and lower parts of the installation casing, this water supply for purification and its separation into the oil and water phase is carried out in the space formed by the upper and lower electrode assemblies, the oil phase that has passed the upper electrode assembly is collected in the upper part Busan removed therefrom electrolysis gases and discharged through the output tube of purified oil, and an aqueous phase that has passed the lower electrode assembly is withdrawn through the withdrawal of purified water pipe, and the resulting solid fraction is removed through the pipe at the bottom of the housing. 2. The method according to claim 1, characterized in that the cleaning is carried out with the addition of a coagulant and a flocculant. 3. The method according to claim 1, characterized in that the electrode assembly contains horizontally and / or vertically arranged electrodes.