Enhancement of Nitrogen and Phosphorus Removal in Pilot-Scale Vertical Subsurface Flow-Constructed Wetlands Using Polypropylene Pellets

Abstract

Removal of nitrogen and phosphorus is known to be somewhat problematic in vertical subsurface flow (VSSF)-constructed wetlands. In this pilot-scale study, two planted (Typha latifolia L.[cattail]) VSSF-constructed wetlands A (with polypropylene pellets) and B (without polypropylene pellets) and one unplanted control C (without polypropylene pellets) were designed to test the contribution of polypropylene pellets to nitrogen and phosphorus removal in eutrophic river water in Tianjin, China. The ranking order of nutrient removal for above tested wetlands was A Ͼ B Ͼ C. In contrast to wetland B, polypropylene pellets in wetland A enhanced the ammonia-nitrogen, total nitrogen, soluble reactive phosphorus, and total phosphorus removal: 13.38%, 8.90%, 9.29%, and 8.25%, respectively. Analysis of the aboveground biomass and nutrient content of the stems and leaves of the T. latifolia indicated that the polypropylene pellets restrained the increase in biomass, but stimulated assimilation of nitrogen and phosphorus into stems and leaves. Additional total nitrogen and phosphorus removal of approximately 29.38 gN/m 2 and 13.47 gP/m 2 by aboveground T. latifolia biomass with polypropylene pellets, respectively, was observed. Outflow water quality of wetland with polypropylene pellets was generally better than without polypropylene pellets during the whole period of the test run. Polypropylene pellets improved nitrogen and phosphorus removal, especially in August, when it apparently stimulated wetland microbial activity.

Phosphorus Accumulation Pattern in a Subsurface Constructed Wetland Treating Residential Wastewater

“…A number of studies have indicated that addition of reactive Ca (CaO or Ca(OH) 2 ) is more efficient in improving the P adsorption capacity that Al and Fe addition [11,37,38]. In agreement with findings reported by Tanner et al [39] and Tang et al [40], the OM accumulation was highest in the inlet zone of the Sadowa wetland, but in some cases the OM content also increased in the outlet zone of the HSFCW (Figure 3). Contrary to our results, Tanner and Sukias [41] observed higher OM accumulation in the top layer (<10 cm) of planted and unplanted constructed wetlands.…”

DISTRIBUSI NITROGEN DAN FOSFOR PADA BUDIDAYA IKAN GABUS (Channa striata) DENGAN APLIKASI ECENG GONDOK (Eichhornia crassipes) DAN PROBIOTIK

“…Penggunaan tanaman air sebagai biofilter terbaik dari jenis eceng gondok Eichhornia crassipes (Tang et al, 2009;Vesely et al, 2011). Selain penggunaan tanaman air, upaya penurunan limbah N dapat dilakukan menggunakan probiotik.…”

Ecological Strategy for Eutrophication Control

“…An alternative solution is to use some biofilm carrier, such as polypropylene pellets, to encourage (accelerate) biological nutrient removal. In contrast to the conventional shale-packed wetlands, the presence of polypropylene pellets would enhance removal of NH 4 -N, TN, SRP and TP by 13.38%, 8.90%, 9.29% and 8.25%, respectively (Tang et al 2009a). …”

“…Constructed wetlands are engineered systems that have been designed and constructed to utilize natural processes involving wetland vegetation, substrate and their associated microbial assemblages to assist in treating wastewater (Vymazal 2007;Tang et al 2009a). These systems take advantage of physical, chemical and biological processes occurring in natural wetlands, but do so within a semi-controlled environment.…”