Industrial wastewater treatment package
Industrial wastewater
Among the biggest consumers of water are industries and factories, which produce different production effluents in terms of quantity and quality due to the difference in the type of industry and production method. For this reason, industrial wastewater treatment in Nilfam industrial wastewater treatment packages always have a more complicated process than sanitary wastewater treatment packages. For this reason, the design, manufacture, production, installation and operation of industrial wastewater treatment packages require special expertise and skills.
Considering the water crisis and the scarcity of water resources and the high consumption of water in industries, the use of industrial wastewater treatment packages of Kashefan Nilfam Engineering Company in cases such as slaughterhouse wastewater treatment package, livestock wastewater treatment package, hospital wastewater treatment package, electroplating wastewater treatment package The wastewater treatment package for aluminum production, the wastewater treatment package for sugar industries, the wastewater treatment package for food industries, and the wastewater treatment package for dairy industries are very effective and desirable options.
Industrial wastewater treatment methods:
1) Physical methods:
Physical methods in the industrial wastewater treatment packages of Kashefan Nilfam Engineering Company are methods in which the forces and physical properties of materials are used to remove them. Garbage collection, granulation, chemical precipitation, filtration and sedimentation are examples of physical methods of wastewater treatment.
2) Chemical methods:
Chemical methods in the industrial wastewater treatment packages of Kashefan Nilfam Engineering Company are methods in which chemical substances and reactions are used to remove pollutants. Aeration, coagulation and flocculation, ion exchange, pH adjustment are considered chemical methods.
3) Biological methods:
Biological methods in the industrial wastewater treatment packages of Kashefan Nilfam Engineering Company are divided into two categories: aerobic processes and anaerobic processes.
a. Aerobic methods :
In the industrial wastewater treatment packages of Kashefan Nilfam Engineering Company, aerobic processes are carried out by microorganisms in the presence of oxygen. Examples of these processes include the IFAS aerobic wastewater treatment process, the MBBR aerobic wastewater treatment process, and other processes.
b. Anaerobic methods:
In the industrial wastewater treatment packages of Kashefan Nilfam Engineering Company, anaerobic processes are carried out by microorganisms in the absence of oxygen. Examples of these processes include the UASB anaerobic wastewater treatment process, the UAFB anaerobic wastewater treatment process, and other processes.
Due to the difference in the nature of the production processes in different industries, their produced wastewaters are also qualitatively and quantitatively different from each other. The table below shows the parameters that may be present in various industrial wastewaters.
Effluents containing heavy metals, organic compounds such as oils and greases, and agricultural and environmental wastes need to be purified the most. Very high amounts of arsenic, selenium, silver, gold and magnesium are produced as a result of the mining process. Wood preservation operations and the semiconductor industry create arsenic. Very high concentrations of copper, lead and barium are produced in battery production. General manufacturing processes produce oils, organic chemicals, silicon, chromium, manganese and tin.
Heavy metals
It is better not to release heavy metals from the beginning. These metals are not decomposed and accumulate in organic sludge that must be left in landfills. Once these metals are released, it will be much more difficult to treat them than to prevent them from being released. The effective removal of heavy toxic metals from industrial wastewater and their recycling is a big challenge. Companies active in the field of industrial wastewater treatment have been very slow in solving this problem. Separating these metals from wastewater still relies on old methods such as sedimentation and the use of activated sludge.
To read more, you can read the article on the heavy metal wastewater treatment package (removal of chrome).
Organic compounds
Organic compounds are found in wastewater from various industries such as pharmaceuticals, food and beverage processing, and leather manufacturing, as well as in landfills, and waste from CAFOs (confined animal husbandry operations) and medical equipment. Toxic organic compounds are also present in the effluents of weapons manufacturing centers, drug production, and insecticide production.
Micropollutant organic compounds, some of which are EDCs, have been observed in some water sources in America and Europe. These pollutant compounds are mainly due to infiltration of wastewater into water sources, leakage from landfills, and animal husbandry effluents. are obtained. Since EDCs have an effect on aquatic organisms and may threaten human health by contaminating drinking water, a lot of research is being done in the field of detection and disposal of these pollutants. Many experts believe that improving wastewater treatment methods is at the heart of the problem, because if these pollutants are removed from wastewater, they have no chance of entering drinking water.
Oily sewage
Every day, billions of gallons of oily wastewater are produced by various industrial producers and other sources such as water from oil tanks, surface wastewater after rain that flows from parking lots, boiler feeding water, bottom water from ships, wastewater from industrial laundries and leakage from Waste disposal centers are produced. Free oil and grease (FOG) is typically oil that quickly rises to the surface and has a particle size of about 150 microns. The size of oil particles that has been mechanically emulsified is between 20 and 150 microns.
Dissolved oil that is no longer in particulate form includes benzene, phenols, toluene, xylene, and related compounds that can only be separated from water using activated carbon, distillation, or membranes. To study how to purify oil from wastewater, you can read the article on the treatment of oily wastewater.
process water
The industries that need the most wastewater treatment are power plants, semiconductor industry, and pharmaceuticals; Other small industries are in the production of chemicals and oil and gas processing. In many developed countries, thermoelectric power generation accounts for the largest volume of water consumption. In America, nearly 40% of the total water consumption is related to power plants. Vital blood water is considered a powerhouse. Large amounts of water are used for steam production and cleaning purposes in these centers. Only in the United States, thermoelectric power producers and companies that produce the electricity they need using industrial boilers consume more than 70 trillion gallons of water annually (each American gallon is equal to 3.785 liters). For the effective use of water in a power plant, the specific treatment needed by each unit must be done; The quality of the water source, boiler type, discharge requirement and the use or non-use of recycled water inside the power plant affect the type of treatment required for each unit.
Boiler water
Since the boilers used in steam production operate at high temperature and pressure, the water entering these boilers must be purified to a very high quality. Minerals such as silica and silica-based compounds and water hardness ions such as calcium and magnesium can cause clogging of the boiler and reduce the efficiency of the unit.
Steam boilers are cleaned regularly to remove the accumulated impurities (metals such as copper, iron, nickel, zinc, magnesium and chromium and chemical additives); In this way, boiler clogging and corrosion of generator components are prevented. Purification of this type of wastewater, which is called boiler blowdown, is difficult and in some cases it is included in the category of harmful wastewater.
In places where the cost of water is high, maybe the industries want to use the wastewater from the chemical washing of steam boilers
Use compensation water in cooling towers, in fly-ash scrubber, or in flue gas desulfurization system. Depending on the chemical composition of this wastewater, it may be economically viable to recycle metals from it.
Cooling water
In thermal power plants, water is converted into high-pressure steam to turn turbines and generate electricity. Then the steam coming out of the turbine is cooled to become water again, heated and turns the turbines. The condensation process requires a separate water cooling system; This system usually consists of a large number of one-inch tubes that absorb the heat of the steam. The cooling water is passed thousands of times through the tubes in which water and steam flow using one of two closed cycle processes or single pass systems.
Cooling water is exposed to four types of contamination: deposits and mineral scales, corrosion, fouling, and growth of microorganisms. As the volume of cooling water decreases due to evaporation or drift (outflow of non-evaporated water along with water vapor from the cooling system), the concentration of chemicals and their by-products increases. Since the concentration of chemicals and pollutants must be kept at a certain level, periodically the water in the cooling system is emptied and fresh compensating water replaces the emptied water. A few different things can be done with drained water:
- Evacuation to the environment after performing necessary purifications;
Sending to the local water treatment plant;
- Treatment at the power plant using the centers own treatment plant;
However, power plants can avoid the costs imposed by treatment plants for the treatment of wastewater containing organic substances by reducing the water output from the cooling system and, as a result, reducing the required compensating water. Prevent the operation of the cooling tower.
Semiconductor industrial water
Ultrapure deionized water is the largest volume of a chemical that comes into contact with semiconductor chips. An average wafer manufacturing plant consumes between 2 and 4 million gallons of ultrapure water per day, which is roughly equivalent to the water consumption of a city with a population of 40,000 to 50,000 people. Deionized water used in the production of integrated circuits must meet very strict standards and be free of micron particles, bacteria, colloidal silica, total organic carbon (TOC5), bacterial components, temperature-increasing substances and metal ions.
In a very high purity water treatment system for semiconductors, the raw water enters a pretreatment system that removes suspended particles. Then, in a reverse osmosis system, organic substances and ions are separated from the water. The water leaving the reverse osmosis system is collected, ozonated, and exposed to UV light to sterilize it and remove all residual organic carbon. In the next step, the remaining ionic materials are removed by a mixed-bed ion exchanger and the water removed from this bed enters the second reverse osmosis system. Then the water enters the second ultraviolet system, then undergoes absolute filtration 6 and finally passes through an ultrafiltration stage. In this step, the produced water is sent to different points of use through a circulation system.
Several years ago, the semiconductor industry set very tough environmental goals, including a 60% reduction in water use. Today, about 70% of the water used by this industry is either purified and reused on the spot, or its pollution is removed and used in other applications. 20% of this purified water is used in production equipment such as cooling towers and heat exchangers; Another 10% is used in secondary processes such as irrigation of green spaces and toilet siphons.
Water required in the pharmaceutical industry:
In the pharmaceutical industry, clean and compendial water is necessary to ensure the production of healthy and sterile products. Compendial water is any type of water that is used in the final stage of drug use, including pure sterile water, sterile water for injection, sterile bacteriostatic water (slowing down or inhibiting the growth of bacteria) for injection, water Sterile for washing (wounds, surgical clothes, …) and sterile water for breathing.
Manufacturers of pharmaceutical products must be able to comply with strict government regulations to remove enough pollutants from city water for use in pharmaceutical products. In America, USP7 has approved water standards for the pharmaceutical industry set by the US Food and Drug Administration (FDA).
Water for chemical production and oil and gas processing:
In the production of chemicals, the purity of raw materials is very important. The water used for diluting very pure products must be of very high quality. As in other manufacturing businesses, here too, very pure water produced by deionization and membrane filtration is used.
In oil and gas processing, membranes are also used to filter water used in boilers and various processes. In addition, in offshore platforms, membranes can be used to reduce the amount of sulfur. Removing sulfur from seawater, which is used in the injection of offshore oil wells, prevents clogging of parts of oil and gas extraction platforms, prevents the loss of reservoir reserves and keeps production at the highest level. In oil and gas exploration, the high amount of total dissolved solids (TDS) in produced water means that desalination is necessary to reuse this water in more useful applications.
“Produced water”, typically a combination of production water and injected water, is saline contaminated water brought to the surface along with oil and gas. To obtain the maximum amount of oil extraction, water is often injected into oil reservoirs to force the oil to the surface. Finally, both the production water and the water injected with oil and gas are extracted, and with the reduction of the storage of oil reservoirs, the amount of this water in the produced oil increases. This contaminated water constitutes the largest volume of wastewater produced in oil and gas production and its management can be costly. In addition to the very high volume, the produced water has special physical and chemical characteristics that can change greatly depending on the geographical location of the oil field, the geological structure and the type of hydrocarbon product produced, making it a very difficult effluent.
Food and beverage production:
Scientists have warned that if the food industry does not do more to reduce water consumption while increasing food production, it faces a global crisis of water scarcity, growing environmental degradation and a high population of malnourished people. will be. In addition to being used as a raw material in food and beverage industries, water is also used in washing, transporting raw materials, cooking and cooling. A lot of water is turned into steam during the food production process, and the rest is thrown away as waste water. Using todays methods, about 865 gallons of water are used to produce normal food for one person per day, which is very high compared to 13 gallons of water needed for household purposes. As the rich people of the world change their diet from plant protein to animal protein, more water will be needed for food processing.
Water reuse is a great opportunity to increase water efficiency and membranes can be a very important technology in this field. By removing salt and organic compounds from water used in food processing, it can be transformed from an unusable waste water into a high quality usable product. According to food industry standards, purified water for reuse in this industry must at least have the quality of drinking water. For some applications, such as make-up water used in steam boilers or washing with hot water, there are stricter rules.
