Evaluating the potential of Abelmoschus esculentus, Solanum melongena, and Capsicum annuum spp. for nutrient and microbial reduction from wastewater in hybrid constructed wetland.

Abstract

Utilizing engineered wetlands for the cultivation of vegetables can help to overcome the problems of water and food scarcity. These wetlands are primarily designed for wastewater treatment, and their efficiency and effectiveness can be improved by selecting an appropriate substrate. To investigate the potential for nutrient and microbial removal, the Abelmoschus esculentus, Solanum melongena, and Capsicum annuum L. plants were selected to grow in a hybrid constructed wetland (CW) under natural conditions. The removal efficiency of the A. esculentus, S. melongena, and C. annuum L. in the CW system varied between 59.8 to 68.5% for total phosphorous (TP), 40.3 to 53.1% for ammonium (NH4+), and 33.6 to 45.1% for total nitrogen (TN). The influent sample contained multiple pathogenic bacteria, including Alcaligenes faecalis, Staphylococcus aureus, and Escherichia coli, with Capsicum annuum exhibiting a positive association with 7 of the 11 detected species, whereas microbial removal efficiency was notably higher in the S. melongena bed, potentially attributed to temperature variations and plant-facilitated oxygen release rates. While utilizing constructed wetlands for vegetable cultivation holds promising potential to address the disparity between water and food supply and yield various environmental, economic, and social benefits, it is crucial to note that the wastewater source may contain heavy metals, posing a risk of their transmission to humans through the food chain.