Sense assessment of odor pollution from landfill

Abstract: Landfill is an important guaranteed facility for urban management. The sanitary landfill number was 1840 until 2016 in China, and the handing capacity was about 325000 t/d in cities and 13 5000 t/d in countries. The odor complaints of landfills by residents occurred frequently, one reason was the co-construction between landfills and residential areas in China, the other reason is high moisture and organic content in Chinese landfill. Odor pollution was sensory, the scale of odor impact was determined by the parameters collectively known as the FIDO factors (frequency, intensity, duration and offensiveness ) and L factor ( L, denoting the location, which is often taken to be a surrogate for the sensitivity and incorporation of the social and psychological factors that can be expected for a given sensitive area). However, there was no constitutional assessment method for odor environmental impact. Odor assessment was usually avoided or assessed by the conventional atmospheric environment methods. Aiming at this problem, based on odor guidelines, criteria and researches of various countries and regions, taking landfill as an example, an assessment method of odor environmental impact was researched by multi-tool odor assessment including modelling simulation, sniff testing, plant boundary monitoring and so on. Odor concentration, odor intensity, odor frequency and other evaluation factors were obtained through these tools in order to assess odor pollution. There were three main kinds of odor emission sources in this landfill, including the composting workshop (point source because of collection emission), operating surface (area source), intermediate heap (area source). The wind tunnel sampler was used to sample from the area source for odor emission rate. CALPUFF modeling was used to simulate odor concentration and odor frequency. Odor intensity, odor frequency and odor quality of the sensitive area were recorded by sniff testing to evaluate the odor feeling of residents directly. Besides, the odor concentration of landfill boundary was also gotten by monitoring and investigating odor sources, and it was used to inspect if the facilities were operated properly. The results indicated that despite proper odor management and control measurements of this landfill, odor intensity of plant boundary was high to level 4 which represented strong odor by sources investigation. Odor concentration could be greater than 1 000, odor frequency which exceedance of odor concentration 20 was high to 2%-40% in poor air dispersion conditions through modelling simulation. The sensitive area within 1 km from the factory boundary was seriously affected by the landfill smell through sniff testing; The direction-dependent sensitive points around landfill within 0.3-2.8 km were relatively high disturbed and outside 1.8-4.0 km were relatively low disturbed by modelling simulation. What's more, the residential area located on the east of the landfill boundary within 3-4 km was judged as relatively low disturbed from the landfill. This research results can provide an effective assessment approach for odor environmental impact from landfill in China, it also can provide reference and decision-making tools for environmental management departments and polluting enterprises.