Document Type : Research Paper
Abstract
In big cities, considerable amounts of fresh water are allocated to the municipal and industrial usages, and no sufficient water is available for agricultural purposes. As a result, in recent years, utilizing treated municipal wastewater for other purposes and especially for irrigation has brought the attention of many researchers and scientists. In this study, the effects of the treated municipal wastewater of Ahwaz on some of the hydraulic characteristics of soil including saturated hydraulic conductivity (Ks), specific water retention (Sr), and final infiltration rate of the soil (If) at various depths (0-13, 13-26, and 26-40cm) and various irrigation periods (1, 2, 4, and 6 months) were investigated. The irrigation waters used were effluent from Ahwaz Municipal Wastewater Treatment Plant (AMWTP) and Karoon River Water (KRW). The study performed on the lands near the Ahwaz Municipal Wastewater Treatment Plant with a completely randomized factorial design and three replications under no plant culture. The experimental plots were 2.5m × 2.5m in size with a sandy loam texture. After 1, 2, 4, and 6 months irrigation with the AMWTP and KRW, the hydraulic characteristics of the experimental plots at the specified depths of soil were measured and/or calculated. The results of the study showed that irrigation with the AMWTP significantly (P<0.05) increased the final infiltration rate and the saturated hydraulic conductivity (Ks) of soilcompared to the KRW. Also, with increasing the irrigation period from 2 to 4 months, the AMWTP increased more the hydraulic properties of the soil, which could be due to better environmental conditions for the growth of micro-organisms in the Spring season. The results also indicated that with increasing the soil depth, the increasing effect of the AMWTP on the hydraulic properties of the soil decreased.
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