Wastewater treatment from oil products: methods, methods and efficiency

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

At the moment, technologies and means, methods and units, thanks to which wastewater treatment from oil products is carried out, are among the most important means of ensuring environmental protection. In our country, for about five years now, legislatively fixed standards for the purification of liquids discharged by enterprises have been in force. Documentation on this issue establishes the quality and volume of water that can be produced by industrial facilities.

About wastewater

Before considering what the treatment of wastewater from petroleum products should be, it is necessary to clarify the understanding of the terminology. Current standards include rainwater, drainage, the liquid used to wash floors, and infiltration as wastewater. The laws governing the activities of enterprises establish, as well ashow much, when you need to pay for the damage to the environment caused by the work of the company. Also, the enterprise must compensate for the negative impact of harmful compounds, which are rich in discharged water. Centralized sewers are forced to cope with this impact.

Regulations were adopted to tighten control over the accounting of water released into the environment by the enterprise. Laws have been adopted that regulate the aggressive load from the discharged liquid and oblige to reduce the concentration of harmful chemical compounds. Collection and wet cleaning of liquid from oil refinery products is a multi-stage procedure. In each individual case, it is necessary to form a sequence of activities, taking into account the working situation.

About factors

When developing a wastewater treatment system from oil products at an enterprise, it is necessary to take into account how voluminous industrial effluents are, how much they need to be reduced, how actively one should work in terms of reducing the concentration of harmful compounds. At the same time, they remember the standards stipulated at the federal level - they regulate the maximum, maximum concentrations of substances. It must also be remembered that some impurities may be of value, so they must first be isolated from the general waste fluid in order to be used again.

One of the tasks of the wastewater treatment system from oil products is the use of the discharged liquid a second time, if appropriate. To assess the possibility of such use, you must first analyze the nuancestechnological processes. It is important to take into account the peculiarities of the circulating water supply of the enterprise.

Studies have shown that almost always water discharged by an industrial facility contains inclusions of oil refinery products. This is true for all categories, types of firms, for different industries. Among the polluting elements, kerosene and fuel oil, hydrocarbon compounds that cannot be identified, oils, various oil impurities are most often detected. Oil refining products are in the form of an emulsion in solution, they can dissolve completely, but sometimes they are found in the form of a dense surface film, especially noticeable when a liquid enters a reservoir. All substances obtained in the process of oil refining are characterized by a high level of toxicity and are internationally ranked among the most dangerous compounds that enter the environment with industrial emissions.

Approaches: general information

There are different methods of wastewater treatment from oil products. Within the same enterprise, different lines can be implemented. The mechanical process involves the use of specialized traps, sand traps. Settling tanks are equipped and liquid filtration systems are installed. All these installations are among those providing mechanical cleaning.

Possibly complex physical and chemical purification of the liquid. This is realized through flotation systems. Various chemical compounds are used in the installations. Special aggregates are designed for the removal of colloidal inclusions. Used for workcoagulants.

Biological wastewater treatment from oil products involves the use of specially designed ponds. Filters have been developed for this method of liquid purification. Aerotanks have become widespread.

Finally, there are methods that involve the use of a variety of reagents. Impurities are deposited using specialized inclusions. Purification is realized through coagulation and flocculation. Common liquid handling approaches are ion exchange, filter installation, flotation.

Current situation

The problem of water purification from oil and oil products in our country is that most enterprises have outdated systems and equipment. The main percentage was built back in the last century, approximately in the 50s. Today, such systems are still in operation, but outdated equipment is inefficient, so it is not possible to achieve the required quality of liquid purification. As a result, industrial facilities greatly harm the environment, and enterprises that do not install the latest units violate the laws.

Because treatment systems are often unable to cope with the increasing volume of liquids, given the increase in the concentration of hazardous compounds, the quality of the discharged water is getting worse. To some extent, this is due to an increase in the diversity of oil refining products penetrating into discharged liquids. When the systems were first built, engineers couldn't predict this level of pollution, so plants can't handlewith load. The resource depletion of installed systems must be taken into account, due to the continuous operation of facilities without regular performance improvement.

Can it be fixed?

In order for wastewater treatment devices to remove oil products, it is necessary to introduce innovative solutions for the enterprise to work efficiently without violating the current legislation. At the moment, the problem is relevant for a huge percentage of industrial facilities that exist on the territory of our country. It is important to use the latest methodologies. There are many new approaches to wastewater treatment. These help to more effectively protect the environment from the aggressive influence of civilization. According to experts, the introduction of effective cleaning methods will significantly save companies money. However, the reality is that innovation in many firms is unreasonably slow.

Technical features: general information

Modern methods of wastewater treatment from oil products are implemented through the use of specialized systems, which are inherently close to fat traps. It is necessary to choose a specific option, evaluating the features of the chemical composition of the pollution characteristic of a particular object, as well as the percentage of hazardous compounds in the liquid, the level of the emulsion. In grease traps, particles of polluting compounds float up due to the gravitational force, and the water treated in this way is sent to common collectors. Many wastewater treatment systems from processed productsoils operate on a similar system.

Relevance of the issue

Without the correct use of mechanical, biological wastewater treatment from oil products, without the use of other approaches, fluid pollution provokes the death of plants and animals. If the enterprise discharges polluted water, a film or emulsion in the form of drops appears on the mirror surface of the reservoir. Such pollution excludes normal air exchange, harms the ecological status of the territory. Activated sludge cannot develop, natural purification systems are unable to function. Oil poisons the biocenosis.

The industry of our civilization produces several types of pollution. An impressive percentage of emissions is due to the activity of plants specializing in the processing of oil and products derived from it. No less dangerous are transport hubs responsible for the movement of oil, enterprises involved in the creation of machines, the repair of wagons, and the manufacture of chemical goods. An impressive percentage of pollution is due to the activity of automobile factories and areas where cars are washed. Any such object must have local systems for cleaning the discharged liquid. Their activity helps to reduce the level of environmental pollution. The development of cleaning systems is carried out taking into account storm water from street surfaces, roads, drains, snow melters. Stormwater has a relatively low concentration of polluting ingredients, but the volumes are such that large systems need to be built. Snow machine stocks are known for their high concentration of productsoil refining at a relatively modest volume. There is gasoline in storm drains, caused by condensation of exhaust gases, oil spills from cars.

Rules and methods

When choosing the methods of wastewater treatment from oil products available for a particular enterprise, it is necessary to take into account the requirements for the discharged liquid. For example, those can be very hard, so that the water does not interfere with management and fishing in the reservoir. Such oblige to use adsorption cleaning systems. Activated carbon is used for their arrangement.

Defend liquid

Often oil traps are used. This is the name of the container for settling the liquid. This approach is the simplest, classical, but has significant drawbacks. Capacitive sedimentation tanks take up a lot of space, operate with a low level of efficiency. For the liquid to clear, it needs to be given a few hours. In order for the system to work more efficiently, thin-layer modular systems are installed, that is, plate sets located at an angle relative to each other. Due to this internal design, the oil trap for wastewater treatment from oil products operates in a laminar water flow. If there is turbulence, the efficiency of the process is reduced.

In order for the oil trap improved by the system of thin-layer modules to treat wastewater from oil products to work effectively, it is necessary to equip it with the phenomenon of coalescence. The term refers to the chemic althe physical process of enlargement of oil refining products, scattered in volume in the form of small drops, on a hydrophobic surface. As the droplets get larger, they rise to the top layer. Especially relevant is the use of such systems in relation to discharges of machines that melt snow. In order for the efficiency of work with melt water to be sufficient, coagulants must be used. Settling using modules is possible in stacked systems with flow distribution mechanisms for the entire duration of the installation. Thin-layer modules speed up the process of droplet ascent, so aggregate volumes can be somewhat reduced.

Oil traps: nuances

In order for the described method of wastewater treatment from oil products to be effective, it is necessary to correctly design the units involved in the workflow. In traps for oil products, structural elements are required, thanks to which the sediment will independently slide to the bottom while simultaneously raising the emulsion to the upper layer. It is important that there is no turbulence. Design work is carried out taking into account the dispersed oil composition. If it is necessary to reconstruct an already installed trap, when introducing a fine-module system, it is necessary to be guided by the standards adopted at the federal level. Reconstruction work, according to experts, will significantly increase the effectiveness of existing systems. To do this, you need to introduce coalescent modules. Due to them, the effectiveness of cleaning will become greater, while the cost of improvingequipment is relatively small.

Flotation

This method of water purification from oil products is called pressure. The method is effective if the contamination in the liquid is not in the form of an emulsion. The workflow involves the use of flocculants, coagulants. During flotation, the liquid is saturated with air. The process takes place using an injector, a compressor. It is possible to use a jet aeration unit. The required saturation level is up to 0.6 atmospheres. Then the liquid is sent to the working chamber, where air bubbles form a gas-liquid system. They rise throughout the working volume up. In the process of moving, oil refinery sticks to the gas, so everything floats together. Next, the top layer is collected with an oil accumulator.

The ejector flotation method is suitable when it is necessary to remove fatty, oily, oil inclusions. If such a system is used to treat wastewater from oil products, the main contamination with oil and oil ingredients can be removed. Next, the liquid must be sent to the filter for finer processing.

Filtering details

The main idea of such a process is the loading of water with subsequent passage through the filter. The movement of liquid inside the sorption filtration system occurs from top to bottom or in the opposite direction: this is determined by the characteristics of the load. This can be sand or activated carbon. You can use aluminosilicates or special sorbents that capture oil - they are made from polyurethane foam.

Choosing in favor of a particularThe treatment option for industrial wastewater from oil products is determined by the level of contamination of the liquid and the desired outcome. In particular, if the filter works by the adsorption mechanism, if activated carbon is selected as the load, the purification efficiency is estimated at 99.8%. The water that has been treated by this method can be discharged into reservoirs where fish are caught and other activities of a similar sector are carried out. When determining the download format, it is important to keep in mind the speed characteristics. Each option has its own optimal density, which provides a good cleaning result. This parameter must be taken into account.

Types and forms

In order for wastewater treatment from oil products and dyes to be of high quality, it is necessary to take into account the features of the chosen method and its technical parameters. The speed of the filtration process depends on the dirt capacity of the chosen loading option. Each raw material has its own period of the filtration cycle. A low speed allows the liquid to move along a minimal path, due to which a certain percentage of the filter is inactive. At higher speeds, the filtration quality is reduced. Activated carbon is often used - this substance has especially good sorption qualities; but each type of download has advantages and disadvantages. For example, polyurethane foam fillers suffer from the formation of grooves, that is, the liquid does not pass through the entire layer of the used load. The substance has oleophilic qualities, the products of petroleum refining and oils are effectively collected on the internal granular surface. Filtrationthe cycle of such a system is small, and its blocks need to be changed frequently. To regenerate the load, it is washed and squeezed.

The technological scheme of wastewater treatment from oil products using filtration loads obliges to take into account the possible quality level of liquid treatment. For example, when choosing a polyurethane foam filler, the possible concentration level of oil transformation products is up to 15 mg/l. The parameter is explained by the solubility of oil-derived products in water. To obtain waste water in which the amount of pollutants would not exceed 0.05 mg/l, activated carbon should be used. Only such an adsorption filtration system will give such a high quality result.

Biocleaning

The costs associated with the biological treatment of wastewater from oil products are a relatively small price compared to the benefits they bring to the environment. Approaches related to these methods have been actively developed and improved in recent years. In practice, mechanical techniques or chemical cleaning of the liquid are much more often used, but the effectiveness of such treatment also leaves much to be desired. The main disadvantage is the high content of dissolved pollutants and finely dispersed oil products. At the same time, water contains an abundance of other organic inclusions that should not be released into the environment. To remove all harmful compounds, you need to resort to biocleaning.

The main idea of this approach is the ability of some microscopic life forms to apply chemicalsubstances as food sources. Thus, a variety of connections are used. Microscopic organisms use them for their livelihoods, turning polluting compounds into harmless results of oxidative reactions. Biological wastewater treatment from oil products is carried out through the chemical biological destruction of hazardous inclusions when the liquid passes through specialized systems. In them, waters meet with bacterial complexes and numerous protozoa. Inside the installation, optimal conditions are created for the development of useful life forms. To properly use different organisms, you need to create settings that take into account the nuances of their life - nutrition, respiration, development, reproduction.

About factors

In order for the treatment of storm water from oil products, volumes discharged by industrial facilities and liquid obtained from other sources to be effective, when implementing a biological system, it is necessary to take into account the optimal temperature regime. Temperature largely determines the ability of microscopic life forms to exist. This is due to the ability of oxygen to dissolve in a liquid at a certain heating. For most aerobic forms, a suitable level is 20-30 degrees Celsius. If this value is exceeded, the organisms will die, which means that cleaning will become ineffective.

An equally important aspect is the level of acidity. Normal indicators are in the range of 6, 5-7, 5. A certain parameter depends on the type of microscopiclife forms. Some need high acidity, others live in alkaline environments. It is also important to provide nutrients used by bacterial cells for energy and development.

An important factor for bacterial biological treatment is the nutrient level, that is, the daily load per cubic meter of the system and grams of bacteria. When forming cleaning aggregates, it must be taken into account that bacteria feed on toxic compounds, but can only live at a certain concentration of these substances in the environment. If the optimal value is exceeded, the development of bacteria slows down, they may die. For the system to work properly, the concentration of toxins should be checked regularly.

About types

The biological system is somewhat different from the mechanical filtration of wastewater from oil products described above. There are options for systems in which the conditions are as close as possible to natural ones, there are units where the environment is artificially formed. The first type is structures where the liquid is filtered by soil, reservoirs with a water flow. The air provides the liquid with the oxygen necessary for the existence of microscopic life forms. With an artificial installation, breathing is realized through the diffusion of oxygen molecules by reaeration or mechaeration.

More effective than mechanical wastewater treatment from oil products, biological, designed in artificial conditions, requires a biological filter, aeration. An alternative design option is aeration tanks. Such working conditions provide relativelyhigh intensity of ongoing reactions by optimizing the conditions for the vital activity of bacteria. Biological chemical treatment in the factory is more often implemented by filters, aerotanks, ponds created specifically for this facility.

Summing up

Wastewater treatment from oil products by flask, microbes, activated carbon and other means, methods and methods is an urgent problem of modern industry. To ensure the safety of life on our planet, all plants and other facilities where oil refinery products are generated and released into the surrounding world must have highly efficient cleaning systems at their disposal. The enterprise must make a choice in favor of a particular option, taking into account the characteristics of the product that pollutes the liquid, its concentration. It is important to be mindful of federal regulations governing how clean the discharged water must be.