source:LASEN Environmental Protection release date:2018-04-12 Number of reads:5400
1. Project Background
A municipal landfill covers an area of approximately 500,000 square meters and is primarily responsible for handling municipal solid waste and some industrial waste from the city and its surrounding areas. With the city's growing population and economic development, the volume of waste generated has steadily increased, and the landfill now receives around 1,000 tons of waste per day. The large accumulation of waste and its prolonged exposure have led to pervasive foul odors in the surrounding area, severely affecting residents' living environment, triggering numerous complaints, and negatively impacting the city's image.
2. Problem Statement
(1) Complex and Diverse Odorous Compounds
During the accumulation and decomposition of waste, a large amount of malodorous substances are generated, mainly including sulfur-containing compounds (such as hydrogen sulfide and methanethiol), nitrogen-containing compounds (such as ammonia and trimethylamine), volatile fatty acids (such as acetic acid and propionic acid), and aromatic compounds (such as styrene). These malodorous substances have complex compositions, pungent odors, and pose certain health hazards. Long-term exposure may lead to respiratory diseases, nervous system damage, and other problems.
(2) Wide Odor Coverage and Rapid Dispersion
Due to the landfill's large area and open-air waste storage, odorous gases are emitted in an uncontrolled manner. Under the influence of wind, these odors can rapidly spread over several kilometers, affecting sensitive areas such as nearby residential neighborhoods, schools, and hospitals.
(3) Deodorization Difficulty Varies with Seasons
Meteorological conditions and variations in waste composition across different seasons significantly affect deodorization efficiency. In summer, high temperatures accelerate waste decomposition, leading to increased generation of odorous gases, while strong atmospheric convection causes odors to spread over a wider area. In winter, low temperatures can impair the performance of certain deodorization equipment and chemical agents, making it difficult to ensure effective odor control.
3. Client Requirements
(1) Significantly Improve Air Quality
Effectively reduce odor concentrations at the landfill and surrounding areas within a short period, significantly improving air quality to meet national environmental protection standards and local ambient air quality requirements, thereby addressing and eliminating residents' complaints and concerns.
(2) Sustainable Deodorization Effect
Establish a long-term deodorization mechanism to ensure stable and durable odor control performance, without significant decline in effectiveness due to factors such as seasonal changes or fluctuations in waste volume.
(3) Environmental and Safety Requirements
The deodorization technologies and chemical agents employed must comply with environmental regulations, produce no secondary pollution, and have no adverse impact on the waste treatment process or the surrounding ecological environment. Additionally, the safety of deodorization personnel must be ensured, preventing accidents such as poisoning, fires, or other safety incidents.
(4) Cost Control
While meeting the required deodorization performance, efforts should be made to minimize the overall cost of odor control—including expenses related to equipment procurement, operation and maintenance, and chemical usage—to enhance the project's economic efficiency.
4. Challenges in Treatment
(1) Complex and dynamically changing waste composition
Landfill waste originates from diverse sources and has a complex composition that varies significantly over time. This makes it difficult to apply a fixed deodorization method targeting a single type of malodorous substance, necessitating continuous adjustment and optimization of the deodorization strategy—thereby increasing both the complexity and cost of odor control.
(2) Significant influence of meteorological conditions
Meteorological conditions—such as temperature, humidity, wind speed, and wind direction—significantly affect the generation, dispersion, and control efficiency of malodorous gases. For instance, high temperature and high humidity promote microbial activity and waste decomposition, intensifying the production of odorous gases; conversely, strong winds cause rapid dispersion of these gases, reducing the effective coverage area of deodorization equipment. It is challenging to dynamically adjust deodorization strategies in real time to accommodate such variable weather conditions.
(3) Limitations in the installation and operation of deodorization equipment
Landfill sites often feature complex terrain and open spaces, making it difficult to install pipelines and deodorization equipment in certain areas. Moreover, the harsh operating environment at landfills exposes equipment to corrosion and damage, necessitating frequent maintenance and replacement—thereby increasing both the operational costs and complexity of the equipment.
5. Treatment Solutions
(1) Biological Deodorization Technology
Biological deodorization biofilters are installed around the landfill site, utilizing microbial metabolic processes to break down odorous compounds into harmless carbon dioxide and water. These biofilters offer advantages such as high treatment efficiency, low operating costs, and no secondary pollution. Specially designed biological media are packed inside the filter beds to provide a suitable environment for microbial growth. Odorous air is drawn into the biofilter by fans and passed through the media, where microorganisms degrade and remove the malodorous components.
(2) Chemical Deodorant Spraying
Highly effective and environmentally friendly chemical deodorants are selected and applied through a combination of vehicle-mounted fogging units and fixed spraying systems to regularly treat the landfill surface and surrounding areas. These chemical deodorants react with odorous compounds, neutralizing or breaking them down to rapidly reduce odor concentrations. The deodorant formulation is tailored based on the specific types and concentrations of odorous substances present, and the spraying frequency and dosage are adjusted accordingly.
(3) Negative Pressure Collection and Purification System
A negative pressure collection system is installed in the waste handling and storage areas to draw odorous gases into purification equipment via fans for treatment. The purification system employs multi-stage filtration and adsorption technologies to remove particulates, hazardous gases, and odorants from the collected air stream. The treated air is then discharged in compliance with emission standards, significantly reducing uncontrolled (fugitive) emissions of odorous gases.
(4) Enhanced Management and Monitoring
Establish a comprehensive landfill management system to strengthen the classification, collection, transportation, and stacking of waste, thereby minimizing the exposure time and surface area of waste. Additionally, install an online odor monitoring system to continuously track odor concentrations and meteorological parameters at the landfill and surrounding areas. Based on real-time monitoring data, promptly adjust deodorization strategies and equipment operating parameters to ensure consistent and reliable odor control performance.
6.Post-Treatment Performance
(1) Significant Reduction in Odor Concentration
After deodorization treatment, the odor concentration in the landfill and surrounding areas decreased significantly. According to monitoring data from a third-party testing agency, the concentrations of major odor pollutants such as hydrogen sulfide and ammonia decreased by more than 80%, meeting relevant national environmental protection standards and local environmental quality requirements. Nearby residents clearly felt the reduction in odor, their living environment improved significantly, and the resident complaint rate dropped sharply.
(2) Marked Improvement in Air Quality
With the reduction in odor concentration, air quality around the landfill has significantly improved. The unpleasant smells in the air have been largely eliminated, visibility has increased, and the number of days with clear blue skies has risen. Environmental quality in sensitive areas nearby—such as schools and hospitals—has been effectively safeguarded, creating a healthier and more comfortable living environment for local residents.
(3) Long-Term Deodorization Effect Remains Stable
By establishing a long-term deodorization mechanism and integrating multiple deodorization technologies, the system achieves stable and durable odor control. It operates effectively under both high summer temperatures and low winter conditions, successfully managing the generation and dispersion of malodorous gases. After more than a year of operational monitoring, the deodorization performance has consistently remained at a high level, with no significant rebound observed.
(4) Achieving Win-Win Economic and Environmental Benefits
While ensuring effective odor control, the optimized deodorization strategy and equipment selection have reduced treatment costs. At the same time, pollution from the landfill to the surrounding environment has been minimized, avoiding economic compensation claims and social disputes caused by environmental contamination. This has enhanced both the operational efficiency and public image of the landfill, achieving a win-win outcome in terms of economic and environmental benefits.
Website:https://www.dglanshen.com/jobs_9/15.html
