关键词: 家畜, 粪污, 重金属, 资源利用, 风险评价

Abstract: The aim of this study were to evaluate the utilization safety of livestock manure fertilizer in Qingyang City of Gansu Province, to promote the healthy, rationalized and refined utilization of livestock manure resources, and to provide references for realizing the scientific combination pattern of livestock farming and crop planting. The livestock manure samples were collected from the pig farms, cattle farms and sheep farms in this city. After being fermented and matured in a plastic greenhouse, the main hygiene indicators and heavy metal content of the obtained manure fertilizer were determined. The results showed that the two tested hygiene indicators, including the mortality of Ascaris eggs and coliform group count in feces, were in line with the requirements of ′Organic Fertilizer Standard NY 525-2012′. The heavy metal elements mainly found in pig manures were zinc （Zn） and copper （Cu）, with the content of 4 125.00 mg/kg and 342.00 mg/kg, respectively. According to the heavy metal content limit value in ′Technology Code for Land Application Rates of Livestock and Poultry Manure GB/T 25246-2010′, the Zn content in pig manure fertilizer exceeded the maximum limit （3 400 mg/kg） by 21.32%. Furthermore, the Cu content in pig manure fertilizer was higher and exceeded the requirements of some crops. The content of Cr in cattle manure fertilizer was 217.30 mg/kg, which exceeded the relevant standard （150.00 mg/kg） by 44.87%. The heavy metal content of sheep manure fertilizer did not exceed the requirements of relevant standard. In order to avoid the environmental pollution caused by heavy metals, it is recommended that the livestock manures should be treated in a concentrated manner, and the pig manures was suggested to be mixed with the cattle manures or sheep manures in a certain ratio to produce organic fertilizer. In addition, the organic fertilizer should be scientifically applied according to the crop needs.

Key words: livestock, manure, heavy metal, resource utilization, risk assessment