scholarly journals Aquatic macrophytes can be used for wastewater polishing, but not for purification in constructed wetlands

2016 ◽  
Author(s):  
Yingying Tang ◽  
Sarah F. Harpenslager ◽  
Monique M. L. van Kempen ◽  
Evi J. H. Verbaarschot ◽  
Laury M. J. M. Loeffen ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Aquatic Macrophytes ◽  
Nutrient Dynamics ◽  
Nutrient Loading ◽  
Myriophyllum Spicatum ◽  
Controlled Study ◽  
Ceratophyllum Demersum ◽  
Wetland Soil ◽  
Nutrient Distribution ◽  
Azolla Filiculoides

Abstract. The sequestration of nutrients from surface waters by aquatic macrophytes and soils provides an important service of both natural and constructed wetlands. While emergent species take up nutrients from the soil, submerged and floating macrophytes filter nutrients directly from the surface water, which may be more efficient in constructed wetlands. It remains unclear, however, whether their efficiency is sufficient for wastewater purification, and how plant species and nutrient loading affects nutrient distribution over plants, water, and soil. We therefore determined nutrient removal efficiencies of different vegetation (Azolla filiculoides, Ceratophyllum demersum or Myriophyllum spicatum) and soil types (clay, peaty clay and peat) at three nutrient input rates, in a full factorial, outdoor mesocosm experiment. At low loading (0.43 mg P m−2 d−1), plant uptake was the main pathway (100 %) for phosphorus (P) removal, while soils showed a net P release. A. filiculoides and M. spicatum showed the highest biomass production and could be harvested regularly for nutrient recycling, whereas C. demersum was outcompeted by spontaneously developing macrophytes and algae. Higher nutrient loading only stimulated A. filiculoides growth. At higher rates (≥ 21.4 mg P m−2 d−1) 50–90 % of added P ended up in soils, with peat soils becoming more easily saturated. For nitrogen (N), 45–90 % was either taken up by the soil or lost to the atmosphere at loadings ≥ 62 mg N m−2 d−1. This shows that aquatic macrophytes can indeed function as an efficient nutrient filter, but only for low loading rates (polishing), not for high rates (purification). The outcome of this controlled study not only contributes to our understanding of nutrient dynamics in constructed wetlands, but also shows the importance of wetland soil characteristics. Furthermore, the acquired knowledge may benefit the application of macrophyte harvesting to remove and recycle nutrients from both constructed wetlands and nutrient-loaded natural wetlands.

scholarly journals Aquatic macrophytes can be used for wastewater polishing but not for purification in constructed wetlands

2017 ◽  
Vol 14 (4) ◽  
pp. 755-766 ◽  
Author(s):  
Yingying Tang ◽  
Sarah F. Harpenslager ◽  
Monique M. L. van Kempen ◽  
Evi J. H. Verbaarschot ◽  
Laury M. J. M. Loeffen ◽  
...  
Keyword(s):  
Plant Species ◽  
Constructed Wetlands ◽  
Aquatic Macrophytes ◽  
Nutrient Dynamics ◽  
Nutrient Loading ◽  
Controlled Study ◽  
Ceratophyllum Demersum ◽  
Nutrient Distribution ◽  
Azolla Filiculoides ◽  
Sediment Types

Abstract. The sequestration of nutrients from surface waters by aquatic macrophytes and sediments provides an important service to both natural and constructed wetlands. While emergent species take up nutrients from the sediment, submerged and floating macrophytes filter nutrients directly from the surface water, which may be more efficient in constructed wetlands. It remains unclear, however, whether their efficiency is sufficient for wastewater purification and how plant species and nutrient loading affects nutrient distribution over plants, water and sediment. We therefore determined nutrient removal efficiencies of different vegetation (Azolla filiculoides, Ceratophyllum demersum and Myriophyllum spicatum) and sediment types (clay, peaty clay and peat) at three nutrient input rates, in a full factorial, outdoor mesocosm experiment. At low loading (0.43 mg P m−2 d−1), plant uptake was the main pathway (100 %) for phosphorus (P) removal, while sediments showed a net P release. A. filiculoides and M. spicatum showed the highest biomass production and could be harvested regularly for nutrient recycling, whereas C. demersum was outcompeted by spontaneously developing macrophytes and algae. Higher nutrient loading only stimulated A. filiculoides growth. At higher rates ( ≥  21.4 mg P m−2 d−1), 50–90 % of added P ended up in sediments, with peat sediments becoming more easily saturated. For nitrogen (N), 45–90 % was either taken up by the sediment or lost to the atmosphere at loadings  ≥  62 mg N m−2 d−1. This shows that aquatic macrophytes can indeed function as an efficient nutrient filter but only for low loading rates (polishing) and not for high rates (purification). The outcome of this controlled study not only contributes to our understanding of nutrient dynamics in constructed wetlands but also shows the differential effects of wetland sediment types and plant species. Furthermore, the acquired knowledge may benefit the application of macrophyte harvesting to remove and recycle nutrients from both constructed wetlands and nutrient-loaded natural wetlands.

scholarly journals Impact of riparian trees shade on aquatic plant abundance in conservation islands

2011 ◽  
Vol 70 (2) ◽  
pp. 245-258 ◽  
Author(s):  
Magdi Ali ◽  
Samar Hassan ◽  
Abdel-Samei Shaheen
Keyword(s):  
Aquatic Plant ◽  
Submerged Macrophytes ◽  
Myriophyllum Spicatum ◽  
Ceratophyllum Demersum ◽  
Submerged Plants ◽  
Plant Abundance ◽  
Potamogeton Crispus ◽  
Azolla Filiculoides ◽  
Riparian Trees ◽  
Significant Difference

Impact of riparian trees shade on aquatic plant abundance in conservation islands Temperature, acidity, light conditions, total dissolved salts, conductivity, dissolved oxygen, submerged macrophytes and shade and sun path directions were measured at 23 sites along the River Nile banks with aAcacia nilotica growing at water's edge around the First Cataract Conservation Islands. Ceratophyllum demersum and Potamogeton crispus were common in the shaded and unshaded zones, Myriophyllum spicatum and Vallisneria spiralis were found only in the unshaded zone and Azolla filiculoides only in the shaded zone. Banks of the sites surveyed were oriented to five directions (NW, SE, NE, SW, N). There is a significant difference in both the type and density of submerged plants growing under the shade of riparian trees (Acacia nilotica) as compared to unshaded areas. Water column irradiance is the most influential variable dictating the distribution of submerged plants. The area of the shade provided by riparian trees was affected by environmental and/or plant variables. Environmental variables comprised the daily course of the exposition to sun; and plant variables included the area of the tree crown, the height of the tree and geographical position of the tree in relation to sun exposition. Trees on the west bank of the islands at the SW-NE direction have the highest shading effect. The management of tree vegetationmight control incoming solar radiation affecting submerged macrophytes.

Field-Scale Studies of Subsurface Flow Constructed Wetlands for Stormwater Quality Enhancement

1997 ◽  
Vol 32 (1) ◽  
pp. 101-118 ◽  
Author(s):  
Q.J. ROCHFORT ◽  
W.E. Watt ◽  
J. Marsalek ◽  
B.C. Anderson ◽  
A.A. Crowder
Keyword(s):  
Organic Carbon ◽  
Constructed Wetlands ◽  
Suspended Solids ◽  
Nutrient Loading ◽  
Subsurface Flow ◽  
Reaction Rates ◽  
Pollutant Removal ◽  
Order Kinetic ◽  
Dissolved Metals ◽  
Subsurface Flow Constructed Wetlands

Abstract Two subsurface flow constructed wetlands were tested for pollutant removal performance in conjunction with an on-line stormwater detention pond, in Kingston Township, Ontario. The 4.9 m2 wetland cells were filled with 9 mm limestone gravel, and planted with cattail, common reed and spike rush. Changes in nutrient (total organic carbon, PO43- and NH4+), suspended solids and metal (Cu, Pb, Zn) concentrations were used to assess performance. Contaminant removal occurred through a combination of physical, chemical and biological means. As with any biological system, variation in performance of stormwater wetlands can be expected to occur as a result of fluctuations in contaminant loading, contact time and ambient environmental conditions. Storm pond effluent was delivered in continuous flow through the wetlands (during baseflow and event conditions), with a detention time of 1 to 3 days. The wetlands were able to maintain removal rates of up to 39% for orthophosphate even during the more severe conditions of fall dieback. Average removal of suspended solids (46%) and dissolved metals (Cu 50%) remained similar throughout all tests. Organic carbon was reduced by less than 10% during these tests. Low nutrient levels in the pond effluent were supplemented by spiking with sources of carbon, nitrogen and phosphorus during pulsed loading conditions. Daily sampling produced a time series, which illustrated the rates of decline in concentration of nutrients. First order kinetic assimilation rates ranged from 1.7 d-1 for NH4002B to 0.12 d-1 for organic carbon, which were noticeably lower when compared with municipal and industrial wastewater treatment rates. Three methods of sizing stormwater wetlands (impervious surface area, volumetric load and kinetic reaction rates) were compared using the same design storm and data from this study. From this comparison it was seen that the kinetic sizing approach proved to be the most versatile, and allowed for adaptation to northern climatic conditions and anticipated nutrient loading.

scholarly journals Use of grass carp (Ctenopharyngodon idella) as a biological control agent for submerged aquatic macrophytes

2014 ◽  
Vol 32 (4) ◽  
pp. 765-773
Author(s):  
A.F. Silva ◽  
C. Cruz ◽  
R.L.C.M. Pitelli ◽  
R.A. Pitelli
Keyword(s):  
Grass Carp ◽  
Aquatic Macrophytes ◽  
Biological Control Agent ◽  
Body Weight Gain ◽  
Predation Rate ◽  
Control Agent ◽  
Ctenopharyngodon Idella ◽  
Ceratophyllum Demersum ◽  
Grass Carp Ctenopharyngodon Idella ◽  
Submerged Aquatic Macrophytes

This study aimed to evaluate feed preference and control efficacy of grass carp (Ctenopharyngodon idella) on the aquatic macrophytes Ceratophyllum demersum, Egeria densa and Egeria najas. An experiment was carried out at mesocosms conditions with 2,000 liters capacity and water residence time of 2.8 days. C. demersum, E. densa e E. najas biomasses were offered individually with sixty g and coupled in similar quantities of 30 g of each species, evaluated during 81 days, envolving 6 treatments. (1 - C. demersum, 2 - E. najas, 3 -E. densa, 4 - C. demersum + E. najas, 5 - C. demersum + E. densa and 6 - E. najas + E. densa). When offered individually, E. najas and C. demersum presented the same predation rate by grass carp, which was higher than E. densa predation rate. When plants were tested in pairs, the order of feed preference was C. demersum > E. najas > E. densa. E. najas and C. demersum percentage control ranged from 73 to 83%. No relation between biomass consumption and grass carp body weight gain was observed, probably due to differences in nutritional quality among macrophyte species according to fish necessities. Therefore, it is concluded that the use of grass carp is one excellent technique to control submersed macrophytes in Brazil.

Nutrient distribution in the Bosphorus and surrounding areas

2002 ◽  
Vol 46 (8) ◽  
pp. 59-66 ◽  
Author(s):  
E. Okuş ◽  
A. Aslan-Yilmaz ◽  
A. Yüksek ◽  
S. Taş ◽  
V. Tüfekçi
Keyword(s):  
Chlorophyll A ◽  
Black Sea ◽  
Nutrient Dynamics ◽  
Lower Layer ◽  
Water Quality Monitoring ◽  
Nutrient Concentrations ◽  
The Black Sea ◽  
Sea Of Marmara ◽  
Nutrient Distribution ◽  
Northwestern Shelf

As part of a five years monitoring project “Water Quality Monitoring of the Strait of Istanbul”, February-December 1999 nutrient dynamics of the Black Sea-the Sea of Marmara transect are studied to evaluate the effect of discharges given by deep disposals. Through a one-year study, upper layer nutrient concentrations were generally under the effect of northwestern-shelf Black Sea originated waters. This effect was strictly observed in July, when the upper layer flow was the thickest. On the other hand, partly in November but especially in December the northwestern-shelf Black Sea originated water flow was a minimum resulting in similar concentrations in both layers. Nutrient fluctuations also affected the chlorophyll a and POC concentrations as parameters of productivity. The nutrient concentrations decreased with the effect of spring bloom and highest chlorophyll a values were detected in November at Strait stations that did not match to the Sea of Marmara values. This fact represents the time-scale difference between the Black Sea and the Sea of Marmara. On the contrary, high nutrient concentrations in the lower layer (especially inorganic phosphate), and therefore low N:P ratios reflect the effect of deep discharge. Vertical mixing caused by meteorological conditions of the shallow station (M3) under the effect of surface discharges resulted in homogenous distribution of nutrients. Nutrient concentrations of the stations affected by deep discharge showed that the two-layer stratification of the system did not permit the discharge mix to the upper layer.

scholarly journals The effect of ice phenology exerted on submerged macrophytes through physicochemical parameters and the phytoplankton abundance

2015 ◽  
Author(s):  
Wojciech Ejankowski ◽  
Tomasz Lenard
Keyword(s):  
Physicochemical Parameters ◽  
Aquatic Vegetation ◽  
Myriophyllum Spicatum ◽  
Ice Cover ◽  
Water Transparency ◽  
Ceratophyllum Demersum ◽  
Total Biomass ◽  
Eutrophic Lakes ◽  
Macrophyte Species ◽  
Tn:Tp Ratio

<p>The physicochemical parameters of water, the concentration of chlorophyll-<em>a</em> and the submerged aquatic vegetation (SAV) were studied to evaluate the effects of different winter seasons on the biomass of macrophytes in shallow eutrophic lakes. We hypothesised that a lack of ice cover or early ice-out can influence the physicochemical parameters of water and thus change the conditions for the development of phytoplankton and SAV. The studies were conducted in four lakes of the Western Polesie region in mid-eastern Poland after mild winters with early ice-out (MW, 2011 and 2014) and after cold winters with late ice-out (CW, 2010, 2012 and 2013). The concentrations of soluble and total nitrogen, chlorophyll-<em>a</em> and the TN:TP ratio in the lakes were considerably higher, whereas the concentration of soluble and total phosphorus and water transparency were significantly lower after the MW compared with after the CW. No differences were found in water temperature, reaction and electrolytic conductivity. Low water turbidity linked with low concentration of chlorophyll-<em>a</em> after the CW resulted in increased water transparency and the total biomass of the SAV. The negative effect of the MW on the macrophyte species was stronger on more sensitive species (<em>Myriophyllum spicatum</em>,<em> Stratiotes aloides</em>) compared with shade tolerant <em>Ceratophyllum demersum</em>. Our findings show that the ice cover phenology affected by climate warming can change the balance between phytoplankton and benthic vegetation in shallow eutrophic lakes, acting as a shift between clear and turbid water states. We speculate that various responses of macrophyte species to changes in the water quality after two winter seasons (CW and MW) could cause alterations in the vegetation biomass, particularly the expansion of shade tolerance and the decline of light-demanding species after a series of mild winters.</p>

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