Evaluation of Spatial Variability of Soil Arsenic Adjacent to a Disused Cattle-Dip Site, Using Model-Based Geostatistics
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- 作者：Nabeel K. Niazi ; Thomas F. A. Bishop ; Balwant Singh
- 刊名：Environmental Science & Technology
- 出版年：2011
- 出版时间：December 15, 2011
- 年：2011
- 卷：45
- 期：24
- 页码：10463-10470
- 全文大小：964K
- 年卷期：v.45,no.24(December 15, 2011)
- ISSN：1520-5851
文摘
This study investigated the spatial variability of total and phosphate-extractable arsenic (As) concentrations in soil adjacent to a cattle-dip site, employing a linear mixed model-based geostatistical approach. The soil samples in the study area (n = 102 in 8.1 m2) were taken at the nodes of a 0.30 脳 0.35 m grid. The results showed that total As concentration (0鈥?.2 m depth) and phosphate-extractable As concentration (at depths of 0鈥?.2, 0.2鈥?.4, and 0.4鈥?.6 m) in soil adjacent to the dip varied greatly. Both total and phosphate-extractable soil As concentrations significantly (p = 0.004鈥?.048) increased toward the cattle-dip. Using the linear mixed model, we suggest that 5 samples are sufficient to assess a dip site for soil (As) contamination (95% confidence interval of 卤475.9 mg kg鈥?), but 15 samples (95% confidence interval of 卤212.3 mg kg鈥?) is desirable baseline when the ultimate goal is to evaluate the effects of phytoremediation. Such guidelines on sampling requirements are crucial for the assessment of As contamination levels at other cattle-dip sites, and to determine the effect of phytoremediation on soil As.