Effects of Untreated Wastewater Irrigation on Peanut (Arachis hypogea) Productivity and Human Health

Abstract

W ASTEWATER irrigation is used by farmers when water becomes scarce. This work aims to study the effects of wastewater irrigation on the agrarian economy and human health. Irrigation water and soil samples were collected from the Shibin drain and the Al Sharqawia canal. The physicochemical features of the drainage water, canal water, polluted soil, and unpolluted soils were analyzed. The vegetative and productivity traits of peanut plants were evaluated including to their mineral nutrient content, primary metabolic products, and heavy metal content. Irrigation with wastewater resulted in lower pod, seed, and biomass productivity, with reductions of 50%, 52.5%, and 42.9% respectively. Chlorophyll a and chlorophyll b levels were also decreased but carotenoid levels were increased. Wastewater irrigation resulted in a decrease in carbohydrate content, crude protein, lipid, content crude energy, and growth energy, Heavy metal concentrations increased, specifically those of Fe, Mn, Zn, Co, Cu, Pb, and Cd. Peanut plants were found to accumulate heavy metals and store Zn, Mn, Cu, Pb, and Cd in their seeds, proving hazardous to human health. Irrigation with wastewater negatively impacts the general economy and human well-being; therefore, this study recommends the enactment of legislation that prohibits irrigation with untreated drainage and prevents the disposal of domestic, industrial, and agricultural wastewater into irrigation canals.

Assessment of heavy metal accumulation and health risk in three essential edible weeds grown on wastewater irrigated soil

“…Compared to plant leaves irrigated with canal water, the GE of weeds increased in drainage water-irrigated plant leaves, where GE of C. endivia and S. oleraceus irrigated with drainage water are 306.7 and 467.4, while in canal water irrigated plants are 251 and 414.2. These results are disagreed with that of Ahmed et al 14 on peanut crop, who reported that too much deposit of hazardous metals (Mn, Zn Cu, Co, Pb and Cd,). This may reduce carbohydrates production by breaking the photosynthetic electron transport chain 72 .…”

“…In soils watered with drainage water, all anions (Co 3 2- , HCO 3 - , Cl - , and SO 4 2- ) and cations (Ca 2+ , Mg 2+ , and K + ) recorded a greater concentration (Table 3 ). Similar to this, soils irrigated with drainage water showed greater quantities of heavy metals 14 .…”

“…Water and soil analysis were taken from prefious study of Ahmed et al 14 . The pH of the soil in the polluted and unpolluted areas ranged from 6.95 (polluted) to 7.01 (unpolluted), and both areas tended to be neutral.…”

“…Many vegetables are known by their potency to accumulate many heavy metals in the edible parts more than the permissible concentrations identifies by FAO/WHO, for examples; Brassica oleracea L. 13 , Malva parviflor a 16 , Arachis hypogea 14 , Spanish, Cabbage and lettuce 32 , Fragaria ananassa , Triticum aestivum , Lycopersicon esculentum , Saccharum officinarum , and Nicotiana tabacum 33 . Previous studies on all these vegetables recorded reduction in growth triates, biomass and productivity, in addition consuming these contaminated have risk on the human health.…”