Environmental assessment of crop residue processing methods in rural areas of Northeast China

The two main processing methods for crop residue in Northeast China are stove burning for house heating and open burning as a waste product. Neither method is appropriate, as large amounts of pollutants released. This paper, therefore, proposes biomass boilers as a source for rural district heating. In a rural area in Northeast China, the PM2.5 dispersions by the aforementioned three methods were simulated using the AERMOD model and the environmental impacts were assessed. The results show that the maximum peak concentration (MPC) is 1248 μg/m3 for stove burning and 90,602 μg/m3 for open burning; the general average concentration (GAC) is 345 μg/m3 for stove burning and 1897 μg/m3 for open burning. These concentration levels greatly exceed the thresholds established by China, the USA, and the WHO. However, the MPC for biomass boilers is only 2.76 μg/m3, a 99.78% and 99.99% decrease from the stove burning and open burning methods, respectively. The GAC for biomass boilers is 1.3 μg/m3, a decrease of 99.62% and 99.93%, respectively. Meteorological characteristics greatly influence the dispersion patterns of pollutants. In summary, replacing household heating stoves with biomass boilers is a bio-energy utilization method worth implementing widely to substantially improve the local atmospheric environment.