From mine waste to irrigation resource: pervious concrete–treated mine water for vegetable crop irrigation

Existing freshwater resources are inadequate to sustain the demands of agricultural production. Alternative water sources should be considered to mitigate water scarcity and ensure a sustainable supply for food production. Laboratory investigations have shown that pervious concrete can be effective in treating acid mine drainage (AMD) for irrigation use; however, its effect on actual crops under field conditions has not been tested. The main aim of the study is to determine the effects of irrigation using pervious concrete–treated mine water and its impact on the physicochemical contamination of leafy vegetables. A 4 × 4 factorial experiment, involving 4 plant species (spinach, lettuce, cabbage, and beetroot) and 4 water treatments (300 mL tap water and 200, 300, and 400 mL of treated mine water), was conducted using a randomized complete block design (RCBD) with 6 replications over a 90-day period. The concentrations of metals in soils and crops were measured using inductively coupled plasma mass spectrometry. Results showed that treated mine water enhanced plant growth. It also enriched the soil with macronutrients (Na, Ca, and K), promoting plant growth and development. Spinach and lettuce accumulated higher levels of Mn, Fe, Zn, and Na compared to cabbage and beetroot. The estimated daily intake of metals (DIM) was highest for Mn, ranging from 0.016 to 0.407 mgꞏkg−1. Similarly, the health risk index (HRI) for Mn exceeded 1 in all vegetables, suggesting that these crops may pose health risks upon consumption. Despite the effectiveness of pervious concrete–treated mine water for irrigating cabbage and lettuce, which exhibited lower metal accumulation than spinach and beetroot, regular monitoring of Mn concentrations is necessary to ensure food safety.