New insights for enhancing the performance of constructed wetlands at low temperatures

Abstract

Constructed wetlands (CWs) have been widely utilized for various types of wastewater treatment due to their merits, including high cost-effectiveness and easy operation. However, a few intrinsic drawbacks have always restricted their application and long-term stability, especially their weak performance at temperatures under 10°C (low temperatures) due to the deterioration of microbial assimilation and plant uptake processes. The existing modifications to improve CWs performance from the direct optimization of internal components to the indirect adjunction of external resources promoted the wastewater treatment efficiency to a certain degree, but the sustainability and sufficiency of pollutants removal remains a challenge. With the goal of optimizing CW components, the integrity of the CW ecosystem and the removal of emerging pollutants, future directions for research should include radiation plant breeding, improvements to CW ecosystems, and the combination or integration of certain treatment processes with CWs to enhance wastewater treatment effects at low temperatures.

Mechanistic understanding of the pollutant removal and transformation processes in the constructed wetland system

“…Pollution from wastewater in CWs is either removed by the action of microorganisms or uptake by plants during their growth and development stage. Both plant growth and microbiological activity require an optimal temperature range (20–40℃) (Kumar et al, 2017; Liang et al, 2017; Kumar et al, 2019; Ji et al, 2020; Wang et al, 2018). Nitrogen and ammonia in CWs are generally removed through plant uptake mechanisms and microbial processes (nitrification and denitrification) (Akratos & Tsihrintzis, 2007).…”

“…In VSSFCW, the combined layer of bioceramic, anthracite, and zeolite was used as a substrate material which resulted in significantly high efficiency in the removal of COD (73.9-78.7%), TP (87.1-90.9%), TN (88.3-91.5%), and NH 4 + -N (83.8-89.9%), and soluble reactive phosphorus (93.8-98.6%) (Wu et al, 2019). growth and microbiological activity require an optimal temperature range (20-40℃) (Kumar et al, 2017;Liang et al, 2017;Ji et al, 2020;Wang et al, 2018). Nitrogen and ammonia in CWs are generally removed through plant uptake mechanisms and microbial processes (nitrification and denitrification) (Akratos & Tsihrintzis, 2007).…”

Purification of Micro-Polluted Lake Water by Biofortification of Vertical Subsurface Flow Constructed Wetlands in Low-Temperature Season

“…The screening and application of low temperature tolerant microorganisms in VSFCW are less studied. Existing studies only discuss the effect of low temperature resistant microorganisms on the treatment efficiency of VSFCW [26].…”

Performance assessment of local aquatic macrophytes for domestic wastewater treatment in Nigerian communities: A review

“…These systems demand a lot of energy for their mechanical components which results in a significant cost of operation, and maintenance and thus a drawback for many developing regions to invest in ( Olukanni and Kokumo, 2013 ; Almuktar et al., 2018 ; Rahman et al., 2020 ). Thus, in recent times, the use of constructed wetlands which are capable of reducing pollutants in wastewaters is gaining prominence ( Olukanni and Ducoste, 2011 ; Tan et al., 2019 ; Ji et al., 2020 ). These systems utilize physical processes, and chemical and biological interactions that are engineered to mimic the natural occurrences of wetland vegetation, thereby facilitating wastewater treatment ( Nayanathara and Bindu, 2017 ; Babatunde et al., 2016 ; Ji et al., 2020 ; Maine et al., 2007 ; Olukanni and Ducoste, 2011 ; Vymazal, 2011 ; Badejo et al., 2017 ).…”

“…Thus, in recent times, the use of constructed wetlands which are capable of reducing pollutants in wastewaters is gaining prominence ( Olukanni and Ducoste, 2011 ; Tan et al., 2019 ; Ji et al., 2020 ). These systems utilize physical processes, and chemical and biological interactions that are engineered to mimic the natural occurrences of wetland vegetation, thereby facilitating wastewater treatment ( Nayanathara and Bindu, 2017 ; Babatunde et al., 2016 ; Ji et al., 2020 ; Maine et al., 2007 ; Olukanni and Ducoste, 2011 ; Vymazal, 2011 ; Badejo et al., 2017 ). They have been confirmed to serve as a robust sustainable technology with a huge capacity to treat wastewaters and a viable decentralized system to manage domestic wastewater in developing nations ( Olukanni and Ducoste, 2011 ; Olukanni and Kokumo, 2013 ; Tan et al., 2019 ; Vo et al., 2019 ).…”