Recently, the non-point source pollution team of the Institute of agricultural resources and agricultural regionalization of the Chinese Academy of Agricultural Sciences and the Agricultural University of China cooperated to systematically reveal the environmental effects of biogas slurry treatment and utilization technology, and pointed out the direction for its further improvement and optimization. The research results were published in environment international.
Figure 1 impact assessment of different biogas slurry treatment technologies on human health, ecosystem quality, climate change and resource consumption
According to researcher Liu Hongbin, China is a large country of livestock and poultry breeding in the world, and livestock and poultry breeding pollution is an important source of non-point source pollution in China's agriculture. Biogas project has the dual functions of livestock manure treatment and green energy supply, and has been widely used. However, the by-product of biogas project, biogas slurry, due to its large amount of production, high concentration of ammonia nitrogen and organic matter, directly pollutes the environment, and the cost of transportation, treatment and utilization is high. In the past, most researches focused on the treatment efficiency of biogas slurry and fertilizer effect, but ignored its environmental impact. Based on the life cycle assessment, water footprint and sensitivity analysis method, the team and partners found that the storage, treatment, transportation and utilization of biogas slurry are the main links of the impact of biogas project on human health, ecosystem quality and climate change, and the ammonia emission in the storage process and the transportation distance in the utilization process are the main factors affecting the environmental effect of biogas slurry. Under the condition of sealed storage, shortened transportation distance and controlled consumption, the environmental impact of direct land use of biogas slurry is relatively small, which is the first choice for treatment and utilization of biogas slurry. Compared with other technologies, such as biogas slurry flocculation contact oxidation coupling microalgae treatment technology, biogas slurry dilution culture microalgae technology, ammonia stripping and birdstone crystallization, although the added value of the products is high, there are many processing procedures, high cost, environmental impact and other shortcomings. In the future, we should pay more attention to the key technologies, especially the research and development of green flocculants, process optimization, cost saving and consumption reduction Breakthroughs. The research was supported by the national key R & D program of the 13th five year plan and the international exchange program for postdoctoral scholars.