Indirect impacts of irrigation with low quality water on the environmental safety

Abstract

Using low quality water for irrigation is probably one of the main reasons for contaminating the arable lands with potentially toxic elements (PTEs), especially within the arid and semiarid regions. On the other hand, most farmers depend thereon on natural inefficient drainage systems to get rid of excess water flows. It was thought that the hydraulic continuities exist, totally or partially, among (a) the underground waters of the arable lands that receive low quality water for irrigation, (b) the underground waters of the nearby lands that use fresh Nile water for irrigation and (c) the sources of fresh water themselves. Therefore, the following assumptions were considered because of their potentially high ecological implications: H1: soil leakage of low quality irrigation water might have negative consequences on the quality of fresh water itself that is used for irrigating the nearby arable lands. H2: concentrations of potentially toxic elements (PTEs) in irrigation water are probably the main factors controlling their corresponding available and total concentrations in soil. H3: concentrations of PTEs within the edible parts of plants grown on the nearby areas irrigated with fresh water are relatively high and may be considered not suitable for consumption. To investigate the abovementioned hypotheses, irrigation water (fresh Nile, underground and wastewaters), soil and plant samples were collected from three different governorates, i.e. New Salhia (El-Sharqia), ElSaff (Giza) and Meet Kenana (Qualubia). One site from each governorate was selected to represent the arable lands that use fresh Nile water for irrigation while the other sites were irrigated with either the underground water or wastewater solely. Quality of the fresh (Nile) irrigation water used in the studied locations was estimated as class II on the basis of its salinity hazards. The other water samples were estimated to be,according to the same basis, as of potentially high or very high salinity hazards. In case of water sodicity, SAR values did not exceed "13" in nearly most water samples. The BOD and COD values exceeded the acceptable levels (even in the Nile fresh water). Moreover, the measured values in fresh water seemed to be comparable, to some extent, with the corresponding ones estimated for either the underground or wastewaters; accordingly,we accept H1. Concentrations of the PTEs, i.e. Pb, Co and Cd in all the collected water samples, generally, did not exceed the maximum permissible levels (MPLs) recommended by FAO (1994). However, Ni was the only one among the studied PTEs whose concentration exceeded the MPL only in the underground water of New Salhiaduring the summer season. It is worthy to mention that AB-DTPA extractable PTEs were correlated significantly with PTEs concentrations in irrigation water. Also, AB-DTPA extractable PTEs were correlated significantly with their total contents in soil; hence, we partially accept the second hypothesis i.e. H2 Furthermore; concentrations of PTEs in the edible parts of plants irrigated w...

Assessing the quality of untraditional water sources for irrigation purposes in Al-Qalubiya Governorate, Egypt

“…wastewater for irrigating crops (Abdel-Fattah &Helmy, 2015 andFarid et al, 2020). This practice is usually accompanied by several environmental and health risks (Abuzaid, 2016(Abuzaid, & 2018a due to pathogens and toxic chemical bioaccumulation (Elbana et al, 2019).…”

Oil Yield and Nutrients Uptake by Irradiated Canola (Brassica napus L.) in Response to Different Nitrogen and Irrigation Water Sources.

“…Shortage in quantity of irrigation water demand is a limiting factor affecting negatively crop productivity in many arid zone soils including the arable lands of egypt (AbdAllah et al, 2019;Aboelsoud andAhmed, 2020 andfarid et al, 2020b). This; consequently, lead us to use other unconventional water resources like wastewater (Abbas and Bassouny, 2018;elcossy et al 2020 andfarid et al 2020a) which became a necessity (Galaviet al, 2010). Treated wastewater is widely recognized as a reliable water source.…”

Monitoring Environmental Pathways of Trace Elements in the Northern East Area of Egypt

“…Distribution of these trace elements (total and AB-DTPA extractable contents) were also determined in the surface and the deeper soil layers collected from the areas nearby water sampling locations, taking into account 3 soil pathways: the first and second pathways extend from south to north-east (referring to the areas relatively nearby Damietta branch and wastewater drains, respectively) while the third pathway extends from the west part of the investigated area to the east part (referring to the arable lands nearby Ismaellia canal). If soil contaminants transfer and re-distribute long distances through the continuity of groundwater aquifer according to Farid et al (2020a) and Bassouny et al (2020), then these contaminants might move from the highlands located at the south part of the Nile Delta aquifer to the low lands located at the north-east/east part of the Nile Delta (Second hypothesis). We also assume that AB-DTPA extractable contents of trace elements are correlated significantly with the corresponding ones in groundwater and this probably indicates that the groundwater is the main source of soil contaminants, particularly TEs.…”