Simulation of managed aquifer recharge: prospects for recycling treated wastewater in Nigeria

Abstract

The study evaluated the potential of recycling treated industrial effluent for groundwater quality and quantity restoration using a laboratory–scale Soil Aquifer Treatment (SAT) simulator. SAT has the potential of reverse groundwater level decline being experienced in the Northeastern part of Nigeria and saltwater intrusion and groundwater quality deterioration in the coastal zones of the country. Soil Column Depth (SDC) and Hydraulic Loading Rate (HLR) were optimized for the best treatment performance. Results show that HLR of 14.6 mm/min at an SCD of 1.5 m gave maximum removal efficiency for all parameters (hydrogen ion concentration (pH), Temperature, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), Dissolved Oxygen (DO), Bio-chemical Oxygen Demand (BOD₅), Total Hardness (TH), Chloride (Cl^¯), Calcium (Ca²⁺), Magnesium (Mg²⁺), Sodium (Na⁺), Potassium (K⁺) and Bacterial Count (BC)) tested in comparison with HLR 16.98 and 20.37 mm/min and SCD of 0.5 and 1.0 m.; This can be attributed to longer contact time in the soil column. Further evaluation of the results from the study indicates that surface spreading is best suited for the Sudan and Sahel Savannah areas of the country. In contrast, direct injection into wells is best suited for the southern and coastal areas. Given that Nigeria has a vast potential for Managed Aquifer Recharge (MAR), the implication is that the implementation requires policy and regulatory frameworks to enable bulk wastewater producers to put their effluents to positive use and thus to enhance environmental sustainability.