The study of soil acidification of paddy field influenced by acid mine drainage

详细信息    查看全文

• 作者：Chipeng Zhang (1) (2)
  Pan Wu (1)
  Changyuan Tang (2)
  Xiuzhen Tao (3)
  Zhiwei Han (2)
  Jing Sun (2)
  Hong Liu (4)
  
• 关键词：Soil acidification ; Basic elements ; Iron enrichment ; Aluminium transformation ; Acidification rate
• 刊名：Environmental Earth Sciences
• 出版年：2013
• 出版时间：December 2013
• 年：2013
• 卷：70
• 期：7
• 页码：2931-2940
• 全文大小：
• 作者单位：Chipeng Zhang (1) (2)
  Pan Wu (1)
  Changyuan Tang (2)
  Xiuzhen Tao (3)
  Zhiwei Han (2)
  Jing Sun (2)
  Hong Liu (4)
  
  1. College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550003, China
  2. Faculty of Horticulture, Chiba University, Matsudo, Chiba, 271-8510, Japan
  3. School of Chemistry and Environmental Science, Guizhou Minzu University, Guiyang, 550025, China
  4. Environmental Monitoring Station, 061 Base, China Aerospace Science and Industry Corporation, Zunyi, 563000, China
  
• ISSN：1866-6299

文摘

The acidification of paddy fields was studied in Guizhou Province, China. Affected by acid mine drainage, the pH value of irrigation water was 2.9 with the concentrations of iron and aluminium above 40?mg/L. Based on the pH(H2O) of topsoil, the paddy fields studied were classified spatially into three zones, the natural zone (pH value from 6.2 to 5.5), the acidified zone (pH value from 5.5 to 4.5), and the seriously acidified zone (pH value from 4.5 to 3.2), respectively. Comparing to the natural zone, the buffering processes for acidification of paddy soil were discussed by considering the changes of calcium, magnesium, potassium and aluminium in soils. The Ca, Mg and K were leached from the soil by the decomposition of carbonate and kaolinite. The leaching of Mg became less with the enrichment of iron in topsoil layer. When the soil pH was below 5.0, aluminium was leached from soil because of the dissolution of alumino silicate minerals. In addition, the hydrolysis of iron and aluminium in soil provided more protons to promote the soil acidification. Furthermore, the buffer capacity of paddy soil was discussed by the results of buffer experiment, based on which the pH buffer curve was drawn and the empirical formula for calculating the acidification rate was developed. Because pH buffer capacity of soil is about 2.78 cmolc/kg pH for the pH(H2O) value above 5.0, it is estimated that only another 50?years are needed for the pH(H2O) of the paddy soil decrease to 3.5 in the acidified zone if the acid water is used for irrigation continuously.