Nutrient recovery from UASB effluent: impacts on Capsicum chinense growth, nutrient accumulation, and productivity
摘要
The use of treated domestic wastewater produced in an upflow anaerobic sludge blanket (UASB) reactor is very attractive since it offers a water source with high concentration of nutrients that can meet the nutritional requirements of plants and positively impact the viability of agricultural production. Chili pepper (Capsicum chinense) is an important crop for family farming in the Brazilian semiarid region. This work aimed to evaluate its cultivation when irrigated with treated UASB effluent, with and without mineral fertilization. No significant differences were observed in the experimental treatments concerning plant height, stem diameter, and P, K, Na, and total chlorophyll contents in leaf tissue. However, the experiment of fertigation with treated sewage using 75% of the recommended dose for pepper cultivation showed the highest dry biomass production (88.40 ± 6.57 g). The highest N and S contents (32.82 and 5.07 g kg−1, respectively) were found in plants irrigated with treated sewage and using mineral fertilizer; their results were significantly different from those found for plants irrigated with water only. The highest fruit yields were obtained in two treatments of plants irrigated with treated sewage (54 to 60 fruits in T3 and T4, respectively); as well as the highest crop yields (1.38 to 1.45 tons ha−1, respectively). The study on Capsicum chinense highlights how using treated wastewater alone or combined with mineral fertilization can support its field cultivation, improve water sustainability and reduce reliance on chemical fertilizers. These findings offer a pathway to enhance large-scale production while maintaining resource efficiency and agricultural resilience.