TRANSPORT AND FATE OF PESTICIDE iN UNSATURATED NONISOTHERMAL SOIL: EXPERIMENTAL AND NUMERICAL STUDIES FOR BROMOXYNIL OCTANOATE. | ||||
| ERJ. Engineering Research Journal | ||||
| Article 10, Volume 31, Issue 4, October 2008, Page 393-400 PDF (393.76 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/erjm.2008.69827 | ||||
 View on SCiNiTO | ||||
| Author | ||||
| I. S. Al-Salamah | ||||
| Department of Civil Engineering, College of Engineering Qassim University. Saudi Arabia | ||||
| Abstract | ||||
| Transport of bromoxynil octanoate (3,s-dibromo-4-hydroxy-benzonitrile) and water were studied experimentally and numerically in closed soil columns. Bromoxynil and water content distributions in the soil columns were measured. A numerical model was developed based upon unsteady state movement of water, heat and nonvolatile organic compound (i.e., bromoxynil octanoate) for simulating the measured data. Loamy sand soil was moisturized then packed in sealed PVC columns (0.10m diameter and 0.3m long). The average bulk density of soil columns was 1439 kg/m3. The soil had initial water content of 0.113 m3/m3. The top 0.005 m- layer of soil column had 0.000272 mol/l of bromoxynil, while the rest of soil column had zero concentration. The columns were buried vertically within a soil bin such that column surfaces were exposed to natural radiation of Qassim region, Saudi Arabia. Two soil columns lasted for 14 days. Both predicted and measured final soil water contents showed nonlinear distributions and similar trends. The water moved from the upper region (0.05 m thick) toward the cold region at depth O.lm. The measured and predicted soil water distributions in the lower layer (i.e., 0.1 to 0.3 m) showed small changes. The predicted and measured bromoxynil concentrations behaved similarly in their &end. The upper 0.0- 0.15 m was an active layer for degradation and movement of bromoxynil. The upper 0.0-0.05 m-region possessed lower concentration of bromoxynil while the succeeded region of 0.05 to 0.15 m possessed the highest concentration. Numerical simulation showed that increasing the mean temperature resulted more migration of water and bromoxynil from upper region toward lower region. | ||||
|
Statistics Article View: 81 PDF Download: 140 |
||||
