水溶肥料重金属含量与安全评价

Content and Safety Evaluation of Heavy Metals in Water-Soluble Fertilizers in China

以5种水溶肥料为研究对象,采用原子荧光光谱法和原子吸收分光光度法检测了As、Hg和Pb、Cd、Cr含量,并采用内梅罗单因子污染指数和综合污染指数对重金属污染程度进行了评价。结果显示,水溶肥料中As、Pb、Cd、Cr、Hg平均含量分别为1.8、15.8、2.4、2.3和0.0 mg kg-1,均符合农业行业标准NY/T 1110-2010限量要求。部分样品中As、Pb和Cd含量超标,超标率分别为4.2%、0.2%和1.0%。5种重金属单因子污染指数都小于0.6,全部为清洁级别,As、Pb、Cd污染程度高于Cr和Hg。5种肥料的综合污染指数在0.14~0.40之间,属于安全级别,综合污染程度从大到小依次为:中量元素水溶肥料≈大量元素水溶肥料>微量元素水溶肥料≈含腐植酸水溶肥料>含氨基酸水溶肥料。总之,水溶肥料重金属产品质量安全,环境风险较小,但As和Cd在大量元素水溶肥料、微量元素水溶肥料和含腐植酸水溶肥料中的安全性值得关注。

Contents of arsenic(As), mercury(Hg) and lead(Pb), cadmium(Cd), chromium(Cr) in 1035 water- soluble fertilizers were measured by using atomic fluorescence spectroscopy and atomic absorption spectroscopy. The samples were collected in twenty- nine provinces in China. The degree of pollution in water- soluble fertilizers was evaluated by applying single factor pollution index and integrated factor pollution index. Results showed that the mean content of As, Pb, Cd, Cr and Hg was 1.8, 15.8, 2.4, 2.3 and 0.0 mg kg- 1, respectively, which was lower than the limitation of agricultural standard NY/T 1110- 2010. As, Pb and Cd in some samples exceeded the limitation, with the percentage of 4.2%, 0.2% and 1.0%, respectively. The single factor pollution index was less than 0.6, which indicated As, Pb, Cd,Cr and Hg were clean level. The pollution degree of As, Pb and Cd was higher than that of Cr and Hg. Nemerow integrated factor pollution index ranged from 0.14 to 0.40, which demonstrated that water- soluble fertilizers were clean and safe level. Results showed that heavy metal pollution in water- soluble fertilizers containing calcium and magnesium was the most severe,followed by water- soluble fertilizers containing nitrogen, phosphorus and potassium,water- soluble fertilizers containing micronutrients, water- soluble fertilizers containing humic- acids and amino- acids.In summary, the content of heavy metals in water- soluble fertilizers was low, and it was safe for the environment.However, more attention should be paid to As and Cd, especially in water- soluble fertilizers containing nitrogen,phosphorus, and potassium, water- soluble fertilizers containing micronutrients and humic- acids.