LT4323B - Method for purification of waste water - Google Patents

Abstract

Invention applies to the field of water, also industrial and domestic wastewater treatment. The invention describes a method that is distinguished by the fact, that the wastewater stream at the same time affected by thermal shock, ozone, ultrasound and ultraviolet radiation, also by accompanying factors evolving when the wastewater stream is treated by short but powerful pulses of E,H fields. Configuration of the treated stream and system parameters are selected so, that is would be possible to treat with heavy ultraviolet radiation as well as air saturated as a result of discharge by the emerging ozone, which in it's own turn is activated by a magnetic field, accompanying radiations and radicals increasing it's effect of rendering it harmless.

Description

The present invention relates to the treatment of water as well as industrial and domestic wastewater, and describes a method of treating wastewater using magnetic and electric fields.

Water treatment methods using stationary magnetic fields are still known today. Such treatment often favors better coagulation of iron compounds and hardness-determining salts, but is ineffective against bacterial flora.

Flow ozonation is also known to facilitate water purification and decontamination, and some systems use the ozone injection into treated water in a consistent manner (e.g., U.S. Patent No. 5,190,648).

A known method of purifying liquids (see U.S. Patent No. 5130032), by this method, pumps a liquid into a purification circuit, provides an electrostatic charge to the liquid, and injects ozone, which is previously subjected to a stationary magnetic field. The liquid is then cooled, returned to its original container, the activator (hydrogen peroxide and sodium peroxide) added and the liquid irradiated with ultraviolet light.

All operations in this mode serve to achieve the desired result. However, all the stages that make up a way extend in time and space. The need to cool the liquid between purification steps and to add an activator requires sophisticated technology and equipment.

All known cleaning methods are practically ineffective in purifying wastewater, which contains plague, cholera carriers, worm eggs.

Also, a method for purifying water flow has been developed (see application PCT / RU92 / 00006), which uses a pulsed electrical discharge of a concentrated type on a horizontal surface of a two-media separating surface of the water to be cleaned. This method proved to be effective, but the discharge area was not wide enough and the purification system proved to be sensitive to variations in the thickness of the treated water flow layer.

It is an object of the present invention to provide an effective method of purifying wastewater using electrical discharges.

Another object of the invention is to provide a flow of a contour such that small variations in the thickness of the liquid layer are present in the processing zone.

Yet another object of the present invention for the same compact waters, ranging from severely inorganic streams, is to enable one and the scheme to treat a variety of relatively pure waters and contaminated organic or pollutants.

In accordance with the present invention, the effluent stream is simultaneously subjected to thermal shock, ozone, ultrasonic and ultraviolet radiation as well as the accompanying factors resulting from the effluent stream processing by short and powerful E, H field pulses. In addition, the configuration and system parameters of the stream to be treated are selected in such a way as to maximize exposure to intense ultraviolet radiation as well as air, discharge ozone-saturated, which in turn is activated by magnetic fields, accompanying radiation and radicals increasing its decontaminating activity .

In the embodiment of the present invention, the effluent stream is first passed through conventional mechanical filters and through a device for retaining fine particles;

- thereafter, by means of a slit-maker, forms a continuous closed falling water stream;

- directs the flow of waste water of the required configuration and thickness to the inter-electrode space of the reactor;

- in the interelectrode space of the reactor, the flow is processed by short and powerful pulses of E, H fields, using potential and equipotential electrodes arranged in several levels in the appropriate order. With their spikes, the electrodes are directed towards, but not touched by, the incident flow, and the potential electrodes are positioned inside the closed loop so that the discharges are perpendicular to the flow according to its outline. Discharges from the potential electrodes to the equipotential occur through the layer of fluid being cleaned at a frequency corresponding to the pulse frequency. The rapid dissipation of energy in the plasma electrical discharge channel allows for a sudden local increase in temperature (up to 5000 -15000 ° C) called a thermal shock. It involves the burning of organic matter - oil, fat, petroleum products - but no change in the mass of the water;

flow from the reactor area to the ejector; there, owing to the flow, air is sucked in from the reactor area, which is saturated with ozone and contains peroxides formed as a result of discharges. It is desirable to use means to facilitate the transition from laminar flow to turbulent flow (such as antiturbines that give the flow a rotational motion), thereby further increasing the phase separation surface and cleaning efficiency. The jet flows freely through the ejector and enters the normal reaction chamber (for potable water preparation) or the conventional settler (for waste water treatment). The water is kept in the settler for at least 20 minutes.

When the effluent stream is exposed to stationary E, H fields in a known manner at a field strength of about 250 mA / m, a saturation threshold is reached, where further enhancement of the field strength has little effect on treatment efficiency. The combination of the classic treatment scheme (see Abramov Vodopodgotovka and Fish Sewer) with ozonation also has limited efficiency.

The sequence of short pulse discharges of cold plasma according to the present invention does not create a simple superposition of stationary fields but exhibits a correlative enhancement effect. As a result, with low energy consumption, you can clean the flow tens of times better. In addition, the same level of purification is achieved tens of times faster (see Examples 2-4).

The following table shows the most important technical characteristics of the waste water treatment and decontamination method according to the present invention.

For efficient cleaning according to the present invention, it is important not only to ensure 2500J of energy storage, but also to discharge it within a few (not more than 10) microseconds. In other words, the energy storage device must satisfy the critical discharge condition: capacitance / inductance [FF * FH] not more than 3.

The E-field generated in the interelectrode space of the reactor shall be at least 1000 V / cm. The present invention has been carried out in the range of electric field strength E up to 100,000 U / cm, but it has been observed that Coli-type microorganisms have already died at 2000 U / cm.

The thickness of the jet processed in the interelectrode space must be optimally transparent in order to be exposed to penetrating ultraviolet radiation.

table

Type of sewage Conditionally clean flows Dirty sewage Labor productivity, / or Same, l / sec 16th 4.5 25th 7.0 58 16.0 100 28th 16th 4.5 25th 7.0 58 16.0 100 28.0 Accumulation energy, J 2.5 3.0 5.0 7.5 5 6th 10th 15th Set yield, kVA 7th 10th 25th 40 14th 20th 50 80 Impulse energy density, kJ / cm ^ 20th 20th 20th 20th 40 40 40 40 UV energ. density, kJ / cm ^ 3.5 3.5 3.5 3.5 7.0 7.0 7.0 7.0 Impulse length, sec.10 5 5 5 5 5 5 5 5 Occupied area, rr2 2 2 2.5 3.5 2 4 5 7th

In the practice of the present invention, the intensity of the ultraviolet spectrum, as shown in Table 1, is ten times greater than that obtained with UV lamps.

In addition, the discharge parameters determine the ratio of ultraviolet to ultraviolet radiation so that large molecules of bacterial flora can be destroyed by ultraviolet radiation with maximum penetration. The decontamination process continues due to the operation of ozone-enriched air and after the stream leaves the reactor.

FIG. Figure 1 shows a schematic fragment of a field tile, with the electrode system arranged in several levels in a chess sequence (a chess field).

FIG. Figure 2 shows a fragment of a reactor with three levels of potential and equipotential electrodes.

FIG. Figure 3 shows a schematic diagram of the treatment and decontamination according to the proposed method.

The invention is illustrated by specific examples of a method for purifying and decontaminating wastewater. The following examples are not intended to limit the scope of the invention.

example.

Treatment of waters heavily contaminated with organic pollutants.

From the pig-rearing complex hydro-pumping system feeds the stream through the mechanical filters and sand trap (output parameters: CHDS 20000 mg / 1, bacterial flora ΙχΙΟ ^ ² units / ml, total drops 100 mg / ml) to the flow maker (1). This example employs a flow maker in the form of a square tube with a circular arc. In order to block the flow, it is fed to the mold in the direction of the circumference of the ring.

The bottom of the curved tube is calibrated along the entire circumference of the circular ring, e.g. 5mm wide, slit. When passing through the slit, a uniform cylindrical falling stream is formed whose radius corresponds to the radius of the flow maker ring and the liquid layer thickness does not exceed 5 mm (slit thickness).

The flow falls into the interelectrode space of the reactor formed by a pair of potential and equipotential electrodes arranged in three levels in chess order.

From the high voltage power supply (2) through the energy storage device (3), 500,000 kW and 100 Hz (5 pulse time pulse) pulses. Through the thickness of the incident stream, a series of discharges take place from the potential electrodes to the equipotential electrodes.

The flow, treated with cold plasma, passes through a water deflector into an ejector (7) connected by a tube to the central part of the reactor area (6). With the flow of water, ozone-enriched air is drawn from the central part of the reactor into the ejector and mixed with the treated stream.

This example employs an ejector equipped with an antiturbine which generates a turbulent flow of fluidized fluid.

The treated water from the ejector enters the radial settler for at least 20 minutes. At a water flow rate of up to 20 mm / sec, particulate matter settles in the settler.

The water temperature at the exit from the reactor area is equal to the water temperature at the entrance.

The energy requirement for treatment of heavily contaminated sewage from the pig farm is 1 kW / m3.

Parameters of treated water at reactor outlet: CHDS 300 mg / l, bacterial flora 3 units / l, fat 1.5 mg / l, total drops 50 mg / l.

Comparative Examples 2-4.

To clarify the mutual reinforcing effect, the results of the classical scheme with additional ozonation, the same purification with ozonation and UV lamp irradiation, and purification according to the present invention were compared.

The results are shown in Table 2. (Example 2: Ozonation; Example 3: Ozonation + UV; Example 4: Method according to the present invention as in Example 1).

Table 2

Example / Operating time 0 30sec lmin 5min 7min 10min 12min Phenol, mg / l 4 0.45 0.2 not found not found 2. Fe ^{4 - 4} , mg / l 5 0.4 0.3 0.12 0.12 Oxidation mg / l 6.4 4.9 3.0 1.8 1.8 Quantity of bacteria * + + + T - (7am) (lOval) (12h (Žlval) Phenol, mg / l 4 0.4 0.1 not found 3. Fe ²⁺ , mg / L 5 0.3 0.2 0.1 Oxidation mg / l 6.4 4.0 1.8 1.6 Quantity of bacteria * + + - - (7am) (8pm) Phenol, mg / l 4 0.1 not found 4. Fe ^ ⁺ , mg / l 5 0.2 0.1 Oxidation mg / l 6.4 1.8 1.6 Quantity of bacteria (7am)

*) The bacterial assay was considered negative if 24 hrs. the green color of the seeded sample did not change.

Examples 5-8

Specially prepared model pesticide solutions were treated according to the procedure of Example 1 at a flow rate of 100 mm / sec. The processing was performed at 100 J of stored energy but changed the discharge frequency from 50 to 1000 Hz.

Pesticide concentration (mg / l) before and after purification was determined by chromatography and is shown in Table 3. (Initial concentrations:

example: metaphos, 10 mg / L;

example: carbofos, 50 mg / L;

Example 7: Phosphamide, 50 mg / L;

example: chlorophos, 50 mg / 1).

table

Concentration of pesticides after cleaning according to the invention, mg / l

Example / Discharge frequency, Hz 50 100 300 500 1000 5. 6.1 4.3 2.8 1.3 0.4 6th 40 30th 21st 9.0 4.0 7th 20th 10th 5 1.5 0 8th 45 35 20th 10th 0.6

The process according to the invention, in addition to the cleaning efficiency, has the following advantages:

- small size (the cleaning system in accordance with the present invention uses an area of 2-7 m 2 with a working capacity of 16-100 nP / h);

energy efficiency (energy consumption from 0.35 kW / m ³ in relatively clean water up to 1 kW / m3 in case of significant contamination of wastewater as pig farm waste water);

- Simple service (automatic cleaning).

Claims (8)

DEFINITION OF INVENTION 1. A method of purifying and decontaminating wastewater by subjecting the effluent stream to electric field, ozonation, and ultrasonic and ultraviolet radiation, characterized in that the effluent passes through a flow maker formed by a continuous-falling, fixed-width, configurational flow to the reactor. performs short high-voltage pulses in the reactor, simultaneously acting on the flux E, H, penetrating ultraviolet and ultrasonic radiation, and activating ozone, which spontaneously emit high-voltage short pulses during discharge, and - directing the treated reactor stream to the ejector, where it is additionally exposed to ozone-enriched air. 2. A method according to claim 1, characterized in that it uses a closed-loop slit flow maker. 3. A bud according to claim 2, characterized in that the slit contour forms a circle and the slit width is 3-5 mm. 4. A method according to claims 1-3, characterized in that the interelectrode space is created by pairs of potential-equipotential electrodes arranged in several levels in chess order and oriented in the direction of the current, furthermore, the potential electrodes are contained inside the flow circuit. 5. A process according to claims 1-4, characterized in that the processing in the reactor is carried out by applying to the potential electrodes energy pulses having an energy density of at least 10 kJ / cm ² , a duration of up to 10 seconds and a frequency of 50-1000 Hz. 6. A process according to claims 1-5, wherein the reactor generates an electric field having a voltage of at least 1000 V / cm and discharges with penetrating ultraviolet radiation at an ultraviolet energy density of 3.5 to 7.0 kJ / cm ² , and ultrasound. 7. A process according to claims 1-6, wherein the discharge is performed on the basis of a critical discharge condition, wherein the product of capacitance and inductance is not more than 3. 8. A process according to claims 1-7, characterized in that in the ejector the flow is changed from laminar to turbulent and the ozone-enriched air is supplied from the reactor area.