Wet Scrubber on Incinerator: Chemical Composition of Contaminants, Types of Scrubbers, Purification of Wastewater

Author: Michael Klepik, Chief Executive Officer

• Industrial: These are refuse materials generated during the production processes of various industries, including plastics manufacturing, textiles, metallurgy, and others. They may include hazardous substances and wastes requiring special handling.
• Medical: These can be byproducts from hospitals, laboratories, veterinary clinics, and other medical facilities that may contain infectious materials or hazardous chemicals.
• Materials requiring specialized treatment due to their hazardous nature or the presence of toxic substances. Chemical, radioactive, and other hazardous substances may fall into this category.

However, while incineration offers several benefits, it also poses environmental concerns, particularly regarding air emissions and the release of pollutants such as dioxins, furans, and heavy metals. To address these issues, modern waste incineration plants are equipped with advanced pollution control technologies that allow minimizing emissions.
In order to minimize air pollution, the incinerator scrubber efficiently removes harmful pollutants before releasing the exhaust into the atmosphere.

Various contaminants can be encountered in incinerators during the waste combustion process. Some of these include:

• Dioxins and furans — toxic organic compounds formed as byproducts of incomplete combustion of waste.
• Nitrogen oxides (NOx) — generated at high combustion temperatures, contributing to smog and acid rain formation.
• Heavy metals — elements such as mercury, cadmium, and lead may be present in waste and released into the atmosphere during incineration.
• Particulate matter — fine solid particles that can carry toxic substances and contribute to air pollution.
• Chlorinated organic compounds — for example, polychlorinated biphenyls (PCBs) or chlorinated solvents.

Effective pollution control systems, such as air and water scrubber for incinerator, help minimize the release of these pollutants into the environment.

Landfill sites consist largely of municipal solid waste (MSW), which includes cardboard, paper, glass, and plastic. A much smaller proportion consists of textiles, metal, wood, and other substances. This heterogeneous waste composition results in landfills being sources of significant methane and carbon dioxide emissions into the atmosphere. Additionally, landfill dust may contain ammonia and hydrogen sulfide, which can cause significant harm to the environment.

Standard composition of landfill gas:

Thanks to the right engineering solutions, our landfill gas scrubber will tackle these tasks and, with proper operation, will provide effective air purification for at least 20 years.

There are several advantages to the use of wet scrubbers and filters in incineration compared to other emissions control methods:
• Proficient at operating seamlessly under high temperatures, ensuring optimal control over emissions even in the most extreme conditions.
• Removes toxic and corrosive substances from exhaust gaseous waste.
• Adapted to various types of contaminants and industrial processes.
• Compliance with environmental standards and regulations through the use of scrubbers can save companies significant amounts in penalties for exceeding emissions limits and environmental taxes.

A wet scrubber incinerator operates by passing the exhaust gases from the incineration process through a scrubbing system that utilizes water or a liquid solution. The exhaust vapors come into contact with the liquid, which traps and absorbs pollutants and particulate matter. These contaminants are then neutralized or removed from the gas stream, resulting in cleaner emissions before they are released into the atmosphere. The liquid used in the scrubbing process may undergo treatment or filtration to ensure effective pollutant removal.

The simplest waste incineration scrubber consists of a hollow cylindrical vessel sprayed inside by water sprayers. The spraying nozzles are located on one or several levels. Multi-level structures create a denser water barrier in the path of the gas flow. Often, cycloning occurs simultaneously: the gas flow does not rise directly from bottom to top but swirls to prolong the contact time with the liquid. The cleaned air exits through the top opening of the water cyclone.

The Venturi scrubber for incinerator is based on the property of gases and liquids to increase their velocity when passing through a narrow channel. The Venturi nozzle consists of an expanded and narrowed section, allowing the contaminated gas to acquire desired characteristics (pressure, velocity). Acceleration of the flow contributes to effective fragmentation of liquid droplets into fine mist, essentially enhancing absorption of pollutants.

Another type of scrubber is based on the use of movable plates with holes in the aerated container. By rotating the plates placed at different levels, foam formation is maintained in the liquid saturated with surfactants. The foam absorbs more contaminants, making the smoke purification system more efficient. The dismountable bubbler is regularly disassembled and flushed of sediments accumulated on the plates, although the main part of the dirt settles in the bottom cone with a float mechanism. Bubbling technique is widely used for low amounts of soot and significant pollution with low-molecular impurities. It ensures high-quality smoke purification from odor and biologically hazardous compounds.

Our expertise lies in modular design, a concept that enhances efficiency and flexibility. By incorporating additional filter modules, we elevate performance seamlessly. Our large-node, bolt-mounted assembly process, akin to assembling furniture, ensures simplicity without the need for welding or intricate maneuvers. With this approach, transporting the filter becomes effortless and time-efficient.

The incinerator scrubber water, a byproduct of the waste incineration process, contains various contaminants that need to be effectively treated before disposal. Treatment methods often involve filtration, chemical precipitation, and biological processes to remove contaminants and ensure compliance with environmental regulations. Additionally, proper management of incinerator scrubber water helps prevent contamination of soil and water bodies, safeguarding public health and ecosystems.

To neutralize incinerator scrubber water, various methods can be employed depending on the specific pollutants present.

Common techniques include pH adjustment using neutralizing agents such as lime or caustic soda to bring the water to a neutral pH level. Additionally, chemical treatments or filtration systems may be used to remove or precipitate heavy metals and other contaminants. Biological treatment processes, such as activated sludge or biofiltration, can also be effective in breaking down organic pollutants. Overall, a combination of physical, chemical, and biological processes is often utilized to effectively neutralize incinerator scrubber water before it is discharged or reused.

In our company, you can order the design, manufacturing, and installation of an aspiration system for an incinerator of any capacity. Our equipment effectively removes debris dust with secondary inclusions, ensuring that the emitted gas meets all environmental standards.