Comprehensive analysis and evaluation of environmental impact of sanitary landfill in Baingoin County, Tibet

The main treatment method of household garbage in Tibet autonomous region is sanitary landfill. Landfills may cause harm and pollution to the surrounding soil, water, air and other environmental elements. The soil, groundwater and air of the landfill site in Baingoin County, Tibet Autonomous Region were sampled and analyzed. The single factor pollution index, land accumulation index and potential ecological hazard index were used to evaluate the impact of the landfill on the surrounding environment. The results showed that the impact of the Baingoin County Landfill site on the surrounding air and groundwater was very small, and the four indexes detected by the air were all lower than the second-level standard value of Emission Standards for Odor Pollutants (GB 14554-93). The heavy metal concentration in groundwater was very low and the evaluation result was safe. The concentrations of heavy metals in the soil were all lower than the risk screening values of Soil Environmental Quality-Risk Control Standard for Soil Contamination of Agricultural Land (Trial) (GB 15618-2018) (pH>7.5). But with Tibetan soil element background values as evaluation criteria, evaluation results showed that the landfill surrounding soil had been polluted by different degrees. Hg had the highest pollution level, and Nemerow index was 2.9-3.5, which belonged to moderate pollution. The potential ecological harm index of Hg was 155-175, reaching the relatively heavy-heavy pollution level. On the whole, the soil around the landfill was in the level of medium potential ecological harm.