Waste management

Odor emissions from waste management

Waste management is one of the areas where odor emissions most frequently cause problems.The stages of the waste management cycle are:

  • collection;
  • transport;
  • treatment for recycling or disposal;
  • recovery or reuse of useful materials;
  • storage and final storage of waste.

Each of these steps can be a source of odor emissions, generated from point or diffuse sources.

Very often the emissions cause nuisance to residents living in areas adjacent to waste management facilities, or to other production activities.

To avoid these problems, action must be taken with both prevention and abatement systems.

The types of waste and odor emissions produced

Waste is classified according to origin:

  • urban waste
  • special waste

and according to hazardous characteristics:

  • hazardous
  • non-hazardous.

Odorigenic emissions that are produced during different waste management cycles are mainly of two types:

  • ducted: when odor is emitted from a specific channel (e.g. through chimneys, wells, tanks);
  • diffuse: when emissions occur from naturally ventilated extended surfaces (e.g. landfill surfaces).

Waste treatment plants

There are different types of waste treatment plants, each with particular characteristics and consequent odor emission problems:

  • composting-biostabilization;
  • treatment and recovery and sorting of Industrial Waste;
  • purifiers;
  • waste-to-energy plants;
  • landfills.

Composting-Biostabilization Plants

These are plants that treat the so-called wet fraction of municipal solid waste.Composting plants turn the organic fraction into compost, to be used as fertilizer in agriculture.

Biostabilization plants allow the treatment of organic waste, and the use is applied in different sectors, including agriculture.

Industrial Waste Treatment and Recovery and Sorting Facilities

They include different types of facilities, in which hazardous and nonhazardous special wastes are treated involving processes, e.g., chemical-physical and biological, aimed at recovery and disposal activities.

Recovery and sorting plants are those that deal with the separation of various types of waste and may be mechanical biological separation or recovery of dry fractions.

Sorting plants mainly receive waste from undifferentiated municipal waste collection, which contains organic fractions that after being treated to recover materials are sent to the incinerator or biostabilizer.

In dry fraction recovery plants, dry waste from separate collection (such as paper, glass, plastic and metals) flows, while the organic fraction generated by kitchens or canteens is sent to anaerobic biodigestion or composting plants.

Finally, for waste with an organic or inorganic matrix that has high amounts of heavy metals, treatment takes place in inerting plants. Waste produced by the sorting and separation processes that cannot be recovered is sent to waste-to-energy or landfill for final disposal.

Sewage treatment plants

Sewage treatment plants are complex and articulated systems capable of treating wastewater.

Wastewaters are those whose quality has been impaired by anthropogenic action after their use in activities such as domestic, agricultural and industrial, thus becoming unfit for direct use as they are contaminated with different types of organic and inorganic substances that are hazardous to public health and the natural environment.

For this reason, they cannot be directly reintroduced into the environment because the final deliveries such as land, sea, rivers and lakes are not capable of receiving a quantity of pollutants in excess of their self-purifying capacity without seeing the normal balance of the ecosystem compromised.

Waste to energy plants

These are plants that, thanks to the incineration of mixed waste, are able to generate energy by producing electricity; they have mechanisms that allow the heat developed by combustion to be used to generate energy.

These plants reach very high temperatures, over 850°C, in order to avoid the production of dioxins. Despite this, they are not a totally green solution, as the combustion of waste generates fumes and ash that contain heavy metals and contribute to the emission of greenhouse gases.

Landfills

The controlled landfill is the place where the final storage of waste on land takes place. Thus, the landfill represents the plant solution for the final disposal of waste that cannot be recovered in a different way.Depending on the type of waste, landfills are classified into three different categories:

  • for inert waste;
  • for nonhazardous waste;
  • for hazardous waste.

Conscious management of waste and the facilities for its treatment

Consciously managing waste is of paramount importance, as it can be a resource that should not be underestimated in terms of energy needs and eco-sustainability.

All waste that is produced, whether at the household or industrial level, is subject to the fundamental phase of collection, and then destined for different treatments according to its type.

Waste treatment plants are essential for the protection of the environment and to avoid dispersion of elements and materials that could cause pollution of natural matrices; issues that can be avoided with proper management.

For example, biogas plants installed at landfills can make a good contribution to the production of clean energy and help reduce greenhouse gas emissions into the atmosphere (as we also explained in this LOD olfactometric laboratory article). Waste management companies therefore need to implement two types of interventions:

  • prevention systems: reducing material staging times, checking for optimal aeration conditions, covering heaps, confinement in closed structures, and process optimization.
  • abatement systems: treatment of ducted and diffuse emissions.

Labiotest's solutions to abate odors in waste management facilities

For each stage of the waste management cycle, Labiotest can analyze the emission problem and propose the best applicable solution.The odor abatement and containment systems we propose are of two types:

  • osmogenic barriers: nebulization systems to spread a solution composed of water and deodorizing product over the odorigenic areas to be treated. They are particularly suitable for odor abatement in the case of diffuse emissions (e.g., landfills, composting plants, water purifiers, etc.), but can also be applied in the case of ducted emissions;
  • filtration plants: operate through chemical-physical adsorption on a multilayer, multi-reagent filter bed specially sized for the type of effluent being treated. They can be used only for piped emissions.

Each emission has specific characteristics and identifying the most suitable solution for its treatment is what we have been doing for over 30 years.

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