Extraction Capacity of Grasses Grown in Constructed Wetland Systems Using Different Arrangements and Substrates

Abstract

Constructed wetland systems have been used to treat different wastewater; among their essential components are the cultivated plant species and type of substrate used to fill them. The choice of plant species and type of substrate are important for the good system performance in wastewater treatment. This study aimed to evaluate the extraction capacity of Napier and Tifton 85 grasses when cultivated at different positions in horizontal subsurface flow constructed wetlands (HSSF-CWs) filled with different substrates in wastewater treatment from a bulk milk-cooling tank (MTWW). The experimental unit consisted of four HSSF-CWs, in which an average surface organic loading rate of 318 kg ha −1 d −1 of BOD5,20 was imposed and a hydraulic holding time of 1.8 and 3.0 d, respectively, in units filled with gravel or crushed PET bottles. Tifton 85 grass presented the highest Na extraction capacity, with better results obtained in HSSF-CWs filled with crushed PET bottles, while Napier grass was more effective in extracting N, K, and P from MTWW. When cultivated in the second half of gravel-filled HSSF-CWs, both grasses provided higher average N extractions when compared to those filled with crushed PET bottles, which had higher extractions in the first half of HSSF-CWs.

Influence of plants on the salinity of constructed wetlands effluents

“…Tifton 85, it seems, removed a higher number of ions in solution as a way to supply its nutritional demand. According to Saraiva et al (2019), Tifton 85 has a high potential for sodium extraction in HSSF-CW due to its high biomass productivity.…”

“…Horizontal Subsurface Flow Constructed Wetlands (HSSF-CW) have been used to treat several types of wastewater, due to their simplicity, low cost, and easiness of operation and maintenance. This treatment systems have as the main objective to reduce the organic load and ion content present in the wastewater (Kadlec & Wallace 2009;Fia et al 2014;Tuttolomondo et al 2015;Almeida et al 2017;Liang et al 2017;Saraiva et al 2019).…”

Efficiency of horizontal subsurface flow-constructed wetlands considering different support materials and the cultivation positions of plant species

“…15 n. 2, e2476 -Taubaté 2020 materials have been evaluated as substrates in different types of systems used for the treatment of wastewater. PET bottles (polyethylene terephthalate), whose disposal has increasingly become an environmental liability, requiring recycling and reuse, have the potential to serve as an alternative support media for HSSF-CWs (Saraiva et al, 2019). Dallas and Ho (2005) studied the efficiency of HSSF-CWs filled with two different substrates: uncrushed PET bottles cut into two or three parts (depending on the size of the bottle) which presented 94% drainable porosity, and gravel which had 40% drainable porosity.…”