Plant Biomass Production in Constructed Wetlands Treating Swine Wastewater in Tropical Climates

Abstract

The production of both aboveground and belowground plant biomass in constructed wetlands (CW) is a poorly understood topic, although vegetation plays an important role in the process of pollutant removal from wastewater. The objective of this study was to evaluate the aboveground and belowground biomass production of Typha latifolia and Canna hybrids in a large-scale constructed wetland treating swine wastewater in tropical climates. Parameters, such as temperature, DO, pH, COD, TSS, TN, TP, and TC, as well as destructive and non-destructive biomass, were evaluated. It was found that, despite the high concentrations of pollutants, the vegetation adapted easily and also grew healthily despite being exposed to high concentrations of pollutants from swine water. Although Typha latifolia (426 plants) produced fewer plants than Canna hybrids (582 plants), the higher biomass of the Typha latifolia species was slightly higher than that of Canna hybrids by 5%. On the other hand, the proximity of the water inlet to the system decreased the capacity for the development of a greater number of seedlings. As for the elimination of pollutants, after treatment in the constructed wetland, COD: 83.6 ± 16.9%; TSS: 82.2 ± 17.7%; TN: 94.4 ± 15.8%; TP: 82.4 ± 23.2%; and TC: 94.4 ± 4.4% were significantly reduced. These results show that wetlands constructed as tertiary systems for the treatment of swine wastewater produce a large amount of plant biomass that significantly helps to reduce the concentrations of pollutants present in this type of water in tropical areas. The use of these plants is recommended in future wetland designs to treat swine wastewater.

Development of Heliconia latispatha in constructed wetlands, for the treatment of swine/domestic wastewater in tropical climates, with PET as a substitute for the filter medium

“…As expected, the DO value was low in the influent, but increased by 2.3 units in the planted system and only 0.7 units on average in the unvegetated system. This performance of the planted systems is similar to the behavior of the large-scale CW treating swine wastewater in tropical climates using the ornamental macrophytes Typha latifolia and Canna hybrid reported by Sandoval-Herazo et al (2021b), where DO increased by 0.7 units, demonstrating the positive effect of using macrophytes in CWs. Also, the pH values increased from 6.6 to 7.7 units in the wastewater when passing through the systems.…”

Effectively Recycling Swine Wastewater by Coagulation–Flocculation of Nonionic Polyacrylamide

“…Lin et al [9] studied producing biogas using a two-stage anaerobic fermentation method. Sandoval-Herazo et al [10] used constructed wetlands to produce biogas from swine wastewater.…”