Suitability of the Decentralised Wastewater Treatment effluent for agricultural use: Decision Support System approach

The study aimed to (i) assess the suitability of AF effluent irrigation water quality for different crops (maize, cabbage and lettuce), soils (coarse sand, sandy loam and clay) in four agro-ecological regions of South Africa, with special focus on impacts on microbial contamination, crop quality, soil quality and environmental pollution, and (iii) provide recommendations for optimizing soil quality, crop yield and human health in DEWATS effluent irrigated soils across agro-ecological regions of South Africa. The South African Water Quality guideline decision support system was parameterized using the characterization data from the Anaerobic Filter (AF) effluent and simulated for a period of 45 years. The model generated the effects of AF effluent on the soil (soil profile salinity, soil permeability, oxidisable carbon loading and trace element accumulation), yield and crop quality in maize, lettuce and cabbage (root zone effects, leaf scorching when wetted, contribution to NPK removal and microbial contamination) and effects on irrigation equipment (corrosion or scaling of irrigation equipment and clogging of drippers)