Document Type : Research Article
Authors
1 Agricultural Engineering Research Institute (AERI), P.O. Box 31585-845, Karaj, Iran
2 Tehran University, Faculty of Agriculture
Abstract
Abstract
Recharge of aquifers by using wastewater, is one of the important and applicable ways for reusing this valuable water resource, especially in arid and semi-arid regions. As the necessity of local practices for finding the proper management strategies and optimum use of recharge systems (conforming to climate, soil, etc.), a preliminary study was carried out. Three physical models were designed and made with a height of 2 m and diameter of 0.6 m. The models were filled with a soil of silty clay sand texture. Treated domestic wastewater of Ekbatan housing complex was used. Transfer of important pollutants indexed by BOD5, COD, nitrogen and phosphorous to shallow grounwaters were studied. Three management practices of wet-dry periods have been used: 1-permanent or long ponding (PP), 2- short period ponding and drying (SP) as 12 hours wetting and 12 hours free drainage, and 3- Moderate ponding (MP) and drying by means of wetting for one week and then drying for another week. The results showed that optimum BOD5, COD and nitrogen reduction occurred in the application of short period ponding management system (mean reduction percentage of 93.5%, 79.5% and 40.4%, respectively). The phosphorous reduction in all strategies was 65% - 75%. The efficiency of microbial indices removal (coliform and fecal coli.) from treated wastewater was high in all management systems. The amount of reduction in this case was between 97% to 99%.
Key words: Artificial recharge, Physical model, Treated domestic wastewater, fecal coliform
)
Send comment about this article