Sustainable water management for cultivating Triticum aestivum L. using treated wastewater with Chlorella vulgaris

This study attempts to address some of the sustainable development goals of the United Nations, specifically, climate action, clean water and sanitation. With the advance of climate change, water shortage is becoming a challenge all over the world. There is a growing global trend for wastewater reuse. Therefore, the present study aimed to investigate the efficiency of the microalgae Chlorella vulgaris in removing nutrients and some heavy metals from EL-Tabia drainpipe at the El-Tabia region in Alexandria, Egypt, and the potential use of algal treated wastewater in irrigating wheat plants (Triticum aestivum L., cv. Masri 3). Chlorella vulgaris successfully eliminated 2.85% aluminium, 7.14% iron, 48.33% manganese, 50% cadmium, 96.30% copper and 98.63% zinc. Wheat plants were irrigated with untreated wastewater (WW), treated wastewater (TWW) or tap water (TW). Plant irrigated with TWW showed an improvement in shoot biomass (39%), protein (40%) and carbohydrate (32%) content, chloroplast ultrastructure, whereas the activity of a catalase (18.1), guaiacol peroxidase (2.13%) and superoxide dismutase (11.7%), malondialdehyde (57%) and H2O2 (64%) contents decreased compared to plants irrigated with WW. Overall, this study suggests the potential of using algal-treated wastewater for crop irrigation which could be a sustainable strategy for disposing of wastewater. However, risk assessment of using treated wastewater on public health is a major concern.