常用化肥重金屬元素含量分析評價及其對土壤環境的影響

王衛星+曹淑萍+李攻科+張亞娜

摘 要：隨著化肥的長期施用，其中的重金屬元素可能會積累，從而導致農田土壤及農作物中重金屬元素超標，造成環境污染，其中，Cd，Hg，As，Pb，Cr是化肥對土壤產生污染的主要物質。以天津市薊州區為例，采集20個常用化肥樣品進行重金屬元素分析評價，并研究其對土壤環境的影響。結果表明，磷酸二銨肥料中As，Cd，Cr含量較其他肥料顯著偏高，尿素、板栗專用肥中As，Cd，Pb含量較其他肥料顯著偏低，復合肥（摻混肥）中As，Cd，Pb，Cr，Hg含量平均為11.06，0.240，2.95，19.7，0.054 mg·kg-1；薊州地區肥料樣品中As，Cd，Pb，Cr，Hg含量均遠遠低于《肥料中砷、鎘、鉛、鉻、汞生態指標》（GB/T 23349—2009）國家標準中的限值，樣品合格率為100%。每年通過化肥可以向每公頃農田土壤中平均輸入As，Cd，Pb，Cr，Hg的質量分別約為13.275，0.315，3.690，33.030，0.076 kg。磷酸二銨和尿素呈堿性，復合肥（摻混肥）均呈酸性，長期大量施用化肥可能會使農田土壤的pH值整體下降。

關鍵詞：化肥；重金屬元素；分析評價；土壤環境

中圖分類號：S143；X53 文獻標識碼：A DOI 編碼：10.3969/j.issn.1006-6500.2017.04.005

Analysis and Evaluation of Heavy Metal Elements in Common Fertilizers and Their Effects on Soil Environment

WANG Weixing， CAO Shuping， LI Gongke， ZHANG Yana

（Tianjin Institute of Geological Survey， Tianjin 300191， China）

Abstract： With the long-term application of fertilizer， the heavy metal elements in the soil and crops can lead to excessive heavy metal elements， resulting in environmental pollution. Cd， Hg， As， Pb， Cr are the main chemical fertilizers for the pollution of the soil. In this study， taking Jizhou district of Tianjin city as an example， 20 common fertilizer samples were analyzed to evaluate heavy metal elements， and studied their effects on soil environment. The results showed that As， Cd， Cr contents of diammonium phosphate fertilizer were significantly higher than other fertilizers. As， Cd， Pb content in urea and special fertilizer for chestnut were significantly lower compared with other fertilizer. As， Cd， Pb， Cr， Hg contents in compound fertilizer （fertilizer blending） were 11.06， 0.240， 2.95， 19.7， 0.054 mg·kg-1， respectively. As， Cd， Pb， Cr， Hg contents in Jizhou fertilizer samples were far lower than the national standard limit value of 《As， Cd， Pb， Cr， Hg ecological indexs in fertilizer 》 （GB/T 23349-2009）， and samples pass rates were 100%. Average input qualities of Cd， Pb， As Cr， Hg through fertilizer to the farmland soil per acre each year were 13.275， 0.315， 3.690， 33.030， 0.076 kg， respectively. DAP and urea were alkaline， and compound fertilizer （mixed fertilizer） were acidic. Long-term use of chemical fertilizers may make the soil pH overall decline.

Key words： chemical fertilizer； heavy metal elements； analysis and evaluation； soil environment

肥料是植物的糧食，農作物的高產離不開肥料的施用，不論是發達國家還是發展中國家，施肥都是糧食增產最有效的措施[1-2]。然而，有些化肥因生產工藝缺陷存在重金屬元素殘留風險，重金屬元素隨著肥料的施用，直接進入農田土壤中，在農田土壤中殘留，長期積累會造成環境污染，從而可能導致農田土壤及農作物中重金屬元素超標[3]。鎘、汞、砷、鉛、鉻是化肥對土壤產生污染的主要物質， 施用進入土壤后富集在農田土壤和作物體內，通過食物鏈最終影響到人體健康；……