Irrigation of Zea mays with UASB-treated textile wastewater; effect on early irrigation of Zea mays with UASB-treated textile wastewater; effect on early growth and physiology

In this study, mature seeds of Zea mays (Malka 16) were irrigated with untreated and UASB-treated wastewater with combination of 50% textile and 50% sewage at hydraulic retention times (HRTs) of 0, 5, 10, and 15 h. Four other treatments diluted with distilled water (DW) were also evaluated. Eight-week analysis of irrigation revealed very small differences in the results of plant biomass and growth parameters of control and those irrigated with 15 h (HRT) treatments. The values of both types of water were observed as chlorophyll a and b contents, 5.9, 3.4, vs 5.5, 3.1 mg g⁻¹, total chlorophyll 9.4 vs 8.8 mg g⁻¹, carotenoids 9.5 vs 8.7 mg g⁻¹, spad values 61.4 vs 56.3, net photosynthetic rate (A) 15.6 vs 14.5 μmol m⁻² S⁻¹, transpiration rate (E) 3.98 vs 3.8 μmol m⁻² S⁻¹, stomatal conductance 5.9 vs 5.8 μmol m⁻² S⁻¹, water use efficiency 10.3 vs 9.7 mmol Cmm⁻¹ H₂O, electrolyte leakage 115 vs 98% and total soluble proteins 385 vs 354 in leaves and 260 vs 231 g⁻¹ FW in roots. While this stress enhanced H₂O₂ 92 vs 115 and 195 vs 224 Units g⁻¹, MDA 6.8 vs 9.1 and 5.9 vs 8.3 Units g⁻¹, activities of enzymatic antioxidants SOD 25 vs 63 and 54 vs 63 Units g⁻¹, POD 1170 vs 1310 and 570 vs 650 Units g⁻¹, CAT 570 vs 820 and 880 vs 1040 Units g⁻¹, and APX 235 vs 278 and 134 vs 187 Units g⁻¹ in leaves and roots, respectively. Heavy metals (Cd, Cr, Cu, and Zn) in such plants were mostly within or about permissible limits of NEQS. The results obtained were more close to that of control. This practice may lead to clean environment and its reuse shall also reduce the stress on fresh water. Early researches transpire a little work done on the reuse of UASB-treated textile wastewater with co substrate, for irrigation purpose.