关键词: 沼液, 沼渣, 养分含量, 重金属, 储存时间

Abstract: To effectively use and manage the biogas slurry and residue, this paper analyzed nutrition and heavy metal contents of biogas slurry and residue in three biogas projects with different raw materials (cow dung, pig manure and chicken manure) in Beijing, ahd discused the temporal variation of nutrition contents of biogas slurry from different raw materials. The results showed that the biogas slurry from chicken manure had the highest contents of total nitrogen and total phosphorus, which were 5 706.23 mg/L and 121.21 mg/L, respectively. The contents of total potassium of the slurry from cow dung was higher than the other two. The biogas residue from pig manure had the highest contents of total nitrogen, which was 31 000.03 mg/kg, and the concentration of biogas residue from chicken manure was 23 951.02 mg/kg. The zinc and copper contents in pig manure fermentation residue and the cuprum contents in cow dung fermentation residue were above the standards for agricultural purpose. Nutrition contents in the three kinds of biogas slurry decreased constantly with the storage time, which showed significant negative correlation. Moreover, the loss ratios of nutrition contents increased as the storage temperature increased in biogas slurry. Nutrition contents of biogas slurry from chicken manure lost more easily than the two other. The results could provide theoretical basis for the biogas slurry and residue storage and its application.

Key words: biogas slurry, biogas residue, nutrition contents, heavy metal, storage time