Bad smell from organic waste handling facilities: Impacts and remedies
December 19, 2023
By Bharat (Bob) Bhushan and Purnima Singh
Bad smell emanating from landfills, garbage transfer stations, sea foods processing and composting facilities is a growing problem worldwide. There are frequent cases of garbage stinks that are highlighted by different media channels based on people’s complaints.
Science of bad smell
Bad smell from organic waste facilities is mainly caused by emissions of hydrogen sulfide, ammonia, mercaptans, and nitrous oxide gases. These gases are by-products of anaerobic respiration mechanism of microorganisms. Production of bad smell from food waste is a biological process where billions of various anaerobic microorganisms are involved in the production of methane, hydrogen sulfide, mercaptans, ammonia, nitrous oxide gases and volatile organic compounds (VOCs), as researchers have noted. Depending on the food waste nutrients such as proteins, carbohydrates, and minerals, the anaerobic microbes use them as the terminal electron acceptors in their cellular energy generation process for their growth and survival. Some biochemical reactions that produce bad smelling gases are shown below:
Biochemical reaction 1: Hydrogen sulphide and methyl mercaptan production by microbial processing of sulphates and sulphites in the food waste.
Biochemical reaction 2: Ammonia production from nitrogen and amino acid in the food waste.
Biochemical reaction 3: Nitrous oxide production by microbial processing of proteins and nitrates in the food waste.
Biochemical reaction 4: Production of VOCs by microbial processing of organic content in the food waste.
Gases produced by microbial processing of food waste have detrimental smell:
- Hydrogen sulphide smells like rotten egg.
- Mercaptans smells like rotten cabbage or garlic due to reduced sulphur compounds.
- Volatile organic acids such as acetic acid smells like vinegar.
- Ammonia smells like urine or sweat.
- Nitrous oxide is a sweet-smelling gas. It’s 300 times more toxic greenhouse gas than CO2.
- VOCs smells like nail polish remover and aldehydes.
The bad smell from commercial garbage handling facilities has severe economic impacts (noted by researchers here). Some of the examples are listed below:
1. Shutting down of waste handling facilities: Facilities shut down cause negative economic impacts in local communities in terms of jobs and taxes loss. Some recent examples are:
- Harvest power compost facility at Richmond, B.C., decided to shut down in 2018 due to bad smell complaints by nearby residents. This led to layoff of about 50 employees working at this facility.
- Hamilton’s compost facility was shut down because of smell issue in 2018.
- People of Rocky View composting facility got a sweet smell of victory in 2019 when county’s elected officials denied it a development permit.
- A potentially improperly zoned, foul-smelling plant in southwest Dallas is shutting down in 2023.
- New Brunswick seafood processing plant was shut down recently in 2023 because of its putrid smell coming from seafood waste composting.
2. Property values: The unpleasant odour and negative perception associated with landfill or waste handling facilities makes nearby properties less desirable, leading to a decrease in property values.
3. Tourism and businesses: The presence of a landfill or waste handling facilities with strong odour can create a negative impression of the area, affecting tourism and economic development. The bad smell can affect nearby businesses, restaurants, hotels, and other establishments that rely on attracting customers may experience a decline in business.
4. Real estate development: Developers may be reluctant to invest in projects near landfills or waste handling facilities due to concerns about the negative impact on property values and marketability.
5. Healthcare cost: The bad smell from landfills or waste handling facilities can have health impacts on nearby residents, leading to increased healthcare costs. Exposure to strong odours can cause symptoms like headaches, nausea, eye, and skin irritation among sensitive population.
Remedies to mitigate bad smell
Currently, there is no foolproof technology available to control the odour issue at waste handling facilities and landfills. However, few different methods are tested and tried to mitigate the effects of bad smell.
- Surrey Biofuel composting facility is spending about 30 per cent of their entire budget into odour abatement. They have four bio-filters, an ammonia scrubber, and a 70-metre stack.
- An electronic nose has been developed to keep tabs on bad odours at waste landfill and water treatment sites.
- Covering the landfill waste with wood chips that act like a biofilter and spraying it with masking or deodorizing chemicals.
- A mobile enclosure vented to a carbon scrubber may be installed in the landfill areas close to residents. Air drawn from the enclosure passing through the carbon scrubbers, cleans the outlet air.
Organic waste is a complex matrix with several variables. After years of research and testing, Alpha Cleantech Labs has developed customized unique methods and techniques to resolve this issue by disrupting the terminal electron acceptor pathways of respiration in microorganisms. This could be done by few different mechanisms:
- By manipulating the biochemistry of anaerobic pathways of microorganisms so that they don’t produce bad smelling gases.
- Outcompeting the smell producing bacteria with beneficial microbes.
- Deactivating smell producing system of microbes.
- Bypassing or replacing the terminal electron acceptor mechanism in microbes.
The method of implementing odour control measures starts with the first step of understanding the food waste chemistry and microbial compositions that is responsible for the odour emissions. In the second step, the remedial measures are applied to the organic waste in form of various physicochemical methods such as using oxygen free radicals to disrupt the terminal electron acceptor pathways, using probiotics to outcompete the bad bacteria, or using sugar dextrin and chemical chelators to deactivate or bypass the bad smell producing mechanisms.
In conclusion, the issue of bad smell from organic waste handling facilities is a pressing concern that affects environment, economy, and the quality of life for those living in the vicinity. It is crucial for authorities and waste management organizations to prioritize finding effective solutions to mitigate this problem by a multi-faceted approach that encompasses technological advancements, community engagement, and sustainable waste management practices. It is vital that resolving this issue not only eliminate the unpleasant odours but also protect our environment and enhance the quality of life for all.
By working together, we can create a cleaner and healthier environment for everyone.
Bharat (Bob) Bhushan, Ph.D., and Purnima Singh, Ph.D., are research scientists with Alpha Cleantech Labs Inc. based in Langley, B.C. www.alphacleantech.com.
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