Removal of nitrogen (N) from hypereutrophic waters by ecological floating beds (EFBs) with various substrates

Appropriate technology for domestic wastewater management in under-resourced regions of the world

“…A solid phase denitrification system, ecological floating beds (EFBs) with various substrates, was tested for the purification of hypereutrophic waters under batch and continuous flow conditions (Cao and Zhang 2014). The addition of biodegradable materials as biocarriers and growth substrates to a planted EFB was thought to promote its purification ability and enhance its plant growth environment.…”

Advanced nutrient removal from surface water by a consortium of attached microalgae and bacteria: A review

“…Ecological floating bed Long retention time, high effluent N/P concentration, low efficiency in cold seasons, low efficiency in deep water Hu et al (2010), Cao and Zhang (2014) Constructed wetland Long retention time, high effluent N/P concentration, large area, low efficiency in cold seasons, long setting up phase Li et al (2008), Dunne et al (2013) Macro hydrophyte pond Long retention time, high effluent N/P concentration, low efficiency in cold seasons, long setting up phase Das et al (2009) Functional microbes Long retention time, potential secondary pollution, high dependence on organic carbon availability, unstable community and easy to crash Sheng et al (2013); Michaud et al (2014), Chen et al (2015) treatment by CW (Dunne et al, 2013). These relatively high remaining nutrient concentrations make it difficult to meet the strict standards for surface water quality (e.g., less than 1.5 and 0.1 mg L À1 for TN and TP, respectively), and innovative approaches for advanced nutrient removal are urgently needed.…”

“…The nutrient-removal performance of EFB and CW fluctuates widely over the seasons and need a long retention time (Table 1) (Dunne et al, 2013;Cao and Zhang, 2014), while functional microbe bioaugmentation has requirements that typically cannot be met (Table 1) (Michaud et al, 2014;Chen et al, 2015). For instance, Cao and Zhang (2014) reported only a minimal reduction of TN to 3.9 mg L À1 with an EFB. Hu et al (2010) reported that TN and TP remained at 2.5 and 0.15 mg L À1 , respectively, in a lake after treatment with an EFB.…”

“…Examples are the ecological floating beds (EFB), constructed wetlands (CW), macro hydrophyte ponds and addition of functional microbes (Pieper and Reineke, 2000;Li et al, 2008;Cao and Zhang, 2014). The nutrient-removal performance of EFB and CW fluctuates widely over the seasons and need a long retention time (Table 1) (Dunne et al, 2013;Cao and Zhang, 2014), while functional microbe bioaugmentation has requirements that typically cannot be met (Table 1) (Michaud et al, 2014;Chen et al, 2015). For instance, Cao and Zhang (2014) reported only a minimal reduction of TN to 3.9 mg L À1 with an EFB.…”

Coal fly ash enhanced planted-floating bed performance in phosphorus-contaminated water treatment

“…In this context, the biological removal of P using planted float technology has gained increasing attention as an alternative in-situ treatment for excessive nutrients (including P) in natural (Zhu et al, 2011;Bu and Xu, 2013;Cao and Zhang, 2014) and seminatural water systems such as constructed wetlands (Vohla et al, 2011;Chang et al, 2013). This technology can treat high hydraulic loading, and plants generate additional economic and ecological benefits (Zhu et al, 2011;Bu and Xu, 2013).…”