Feasibility assessment: application of ecological floating beds for polluted tidal river remediation

Abstract

The remediation of polluted coastal rivers is a global challenge in the environmental field. The objective of this study was to investigate the remediation feasibility of a high-salinity river using water spinach (WS) and sticky rice (SR) in hydroponic floating-bed systems. In this study, the total nitrogen (TN) removal rates were 89.7, 92.3, 85.1, and 75.2% in the WS floating-bed system and 81.2 and 78.9% in the SR floating-bed system under different salinities (2-31 psu). Additionally, the total phosphorus (TP) removal rates were 94.4, 96.4, 93.5, and 75.2% in the WS floating-bed system and 75.7 and 80.0% in the SR floating-bed system under different salinities. The results indicate that WS and SR significantly contributed to the remediation of a polluted tidal river. Additionally, increased salinity suppressed the removal of ammonium and phosphate by WS and SR. The salt tolerance of WS was greater than that of SR, which indicated that WS was a more appropriate choice for treating river contamination.

An approach for restoration of the water quality with emphasis on the removal of organochlorine pesticides and eutrophic conditions in tropical rivers

“…The reservoir was categorized as hypereutrophic due to the high concentrations of nutrients (Matos & Rodríguez, 2002). Although these results comply with the regulations for discharges to bodies of water, they represent the characteristics of eutrophic rivers (Bu & Xu, 2013; Sun et al., 2017; Wu et al., 2016).…”

Remediation of Polluted River Water by Biological, Chemical, Ecological and Engineering Processes

“…Flow through riverbed and groundwater aquifer to the pumping wells Remove organic and inorganic contaminants through natural filtration process Slow process [22][23][24][25] Ecological engineering-based techniques, such as plant purification treatment, ecological floating beds, artificial floating islands and constructed wetlands, have attracted the greatest attention due to their overall economic, environmental and ecological benefits, but these methods demonstrate variable performances to remediate polluted river water [9,10,26,27]. The remediation of river water is a critical process which needs the combination of engineering and ecological technologies for successful treatment of river water.…”

“…Planted floating bed systems effectively remove nutrients and increase DO and transparency in urban river water [91]. Sun et al [26] treated polluted saline river water using water spinach and sticky rice in hydroponic floating-bed systems. The water spinach floating-bed system exhibited superior performance in removing total N (75.2-92.3%) and P (75.2-96.4%) under variable salinity stress conditions.…”

Key technologies and equipment for contaminated surface/groundwater environment in the rural river network area of China: integrated remediation

“…As an important component of the ecological floating bed, plants absorb the pollutant in water during their growth period and provide the attachment sites for microorganisms to grow through their developed plant roots. Sun et al [29] investigated the remediation feasibility of ecological floating-bed systems using water spinach and sticky rice, and found that the total nitrogen removal rates reached 92.3% and 81.2%, respectively. Meanwhile, introducing the appropriate carrier in the ecological floating bed can promote the growth of plants and improve their ability to resist contamination stress.…”