scholarly journals Hydraulic investigation of the impact of retrofitting floating treatment wetlands in retention ponds

2019 ◽  
Vol 80 (8) ◽  
pp. 1476-1484 ◽  
Author(s):  
Sher Khan ◽  
Muhammad Shoaib ◽  
Mudasser Muneer Khan ◽  
Bruce W. Melville ◽  
Asaad Y. Shamseldin
Keyword(s):  
Root Length ◽  
Longitudinal Axis ◽  
Hydraulic Performance ◽  
Treatment Wetlands ◽  
Experimental Investigations ◽  
Retention Pond ◽  
Retention Ponds ◽  
Floating Treatment Wetlands ◽  
The Impact ◽  
Stormwater Retention

Abstract This paper describes the laboratory experimental investigations undertaken to analyse the influence of floating treatment wetlands (FTWs) on the hydraulic performance of a stormwater retention pond. Two experimental series were conducted, each focussed on investigating the influence of placing an FTW in a pond with firstly the inflow entering the retention pond from an inlet positioned 0.25 m offset from the longitudinal axis of the pond, and secondly the inlet positioned at the longitudinal axis of the pond. For both series of experiments, tests were undertaken at 1 l/s and 1.5 l/s, and with and without an artificial FTW installed. This study is the first to investigate the hydraulic impact of FTWs and their root systems on the performance of stormwater retention ponds. The results presented in this study suggest that FTWs are a viable method to minimise hydraulic inefficiencies, thereby increasing retention time and optimising hydraulic performance of stormwater retention ponds. The results highlight the importance of plant root characteristics. The optimal arrangement of root length is LR/DP = 0.5, where LR = root length and DP = pond depth. The results also indicate that the spatial variability of vegetation has a significant impact on the hydraulic performance of the pond.

Evaluation of floating treatment wetlands as retrofits to existing stormwater retention ponds

2013 ◽  
Vol 54 ◽  
pp. 254-265 ◽  
Author(s):  
Ryan J. Winston ◽  
William F. Hunt ◽  
Shawn G. Kennedy ◽  
Laura S. Merriman ◽  
Jacob Chandler ◽  
...  
Keyword(s):  
Treatment Wetlands ◽  
Retention Ponds ◽  
Floating Treatment Wetlands ◽  
Stormwater Retention

scholarly journals Sorption and Degradation Potential of Pharmaceuticals in Sediments from a Stormwater Retention Pond

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 526 ◽  
Author(s):  
Fan Liu ◽  
Asbjørn Nielsen ◽  
Jes Vollertsen
Keyword(s):  
Half Life ◽  
Pond Water ◽  
Organic Micropollutants ◽  
Partitioning Coefficient ◽  
Retention Pond ◽  
Retention Ponds ◽  
Water Partitioning ◽  
Stormwater Retention ◽  
Sorption Potential

Stormwater retention ponds commonly receive some wastewater through misconnections, sewer leaks, and sewer overloads, all of which leads to unintended loads of organic micropollutants, including pharmaceuticals. This study explores the role of pond sediment in removing pharmaceuticals (naproxen, carbamazepine, sulfamethoxazole, furosemide, and fenofibrate). It quantifies their sorption potential to the sediments and how it depends on pH. Then it addresses the degradability of the pharmaceuticals in microcosms holding sediment beds and pond water. The sediment-water partitioning coefficient of fenofibrate varied little with pH and was the highest (average log Kd: 4.42 L kg−1). Sulfamethoxazole had the lowest (average log Kd: 0.80 L kg−1), varying unsystematically with pH. The coefficients of naproxen, furosemide and carbamazepine were in between. The degradation by the sediments was most pronounced for sulfamethoxazole, followed by naproxen, fenofibrate, furosemide, and carbamazepine. The first three were all removed from the water phase with half-life of 2–8 days. Over the 38 days the experiment lasted, they were all degraded to near completion. The latter two were more resistant, with half-lives between 1 and 2 months. Overall, the study indicated that stormwater retention ponds have the potential to remove some but not all pharmaceuticals contained in wastewater contributions.

Evaluation of hydraulic performance indices for retention ponds

2015 ◽  
Vol 72 (1) ◽  
pp. 10-21 ◽  
Author(s):  
Arash Farjood ◽  
Bruce W. Melville ◽  
Asaad Y. Shamseldin ◽  
Keith N. Adams ◽  
Sher Khan
Keyword(s):  
Hydraulic Performance ◽  
Hydraulic Efficiency ◽  
Hydraulic Analysis ◽  
Performance Indices ◽  
Sediment Retention ◽  
Retention Pond ◽  
Retention Ponds ◽  
Sediment Retention Ponds ◽  
Moment Index ◽  
Selection Of

Abstract Comprehensive hydraulic analysis of sediment retention ponds is commonly achieved through interpretation of residence time distribution and derivation of indices associated with short-circuiting and mixing. However, the availability of various indices indicates the need for careful selection of the most appropriate indices. This study compares some of the commonly used hydraulic performance indices, together with a new short-circuiting index, τ5, for five different flow regimes in a model sediment retention pond. The results show that τ5 was the best measure for short-circuiting. Among the mixing indices, only the Morril index correctly represented the physical behaviour of the experiments. In addition, two hydraulic efficiency indices, λ and a moment index (MI) were assessed and showed a good correlation with the short-circuiting and mixing indices, but MI was more reproducible than λ. Based on these results, this study recommends using τ5, Morril index and MI for analysis of hydraulic performance in sediment retention ponds.

scholarly journals Experimental investigation of the effect of temperature differentials on hydraulic performance and flow pattern of a sediment retention pond

2018 ◽  
Vol 77 (12) ◽  
pp. 2896-2906 ◽  
Author(s):  
Ehsan Hendi ◽  
Asaad Y. Shamseldin ◽  
Bruce W. Melville ◽  
Stuart E. Norris
Keyword(s):  
Residence Time ◽  
Hydraulic Performance ◽  
Effect Of Temperature ◽  
Sediment Retention ◽  
Small Temperature ◽  
Thermally Induced ◽  
Retention Pond ◽  
Retention Ponds ◽  
Sediment Retention Ponds ◽  
Counter Current

Abstract Existing studies on sediment retention ponds (SRPs) have examined the effects of pond layout, inlet and outlet geometry and the installation of baffles on the performance of the SRPs. However, the effects of a temperature difference between the ambient water in the pond and the inflow are often neglected, and the buoyancy forces arising from these differences in temperature can potentially change the flow in the pond and hence its hydraulic performance. This study has experimentally evaluated the effect of these temperature differences on the flow field and residence time in a retention pond for a range of temperature differences. As expected a cold inflow sinks to the bottom of the pond while a hot inflow remains at the surface, but in both cases the inflow flows more rapidly towards the outlet than is the case for isothermal inflow. A counter-current was observed at the bottom or the surface of the pond for colder or hotter influents, respectively. These thermally induced flows significantly reduced the residence time of the pond, reducing the hydraulic performance of the pond and causing severe short-circuiting. The results have also shown that the temperature differences in the pond decrease with time, yet small temperature differences persist with the pond remaining thermally stratified.

scholarly journals Ornamental plants for floating treatment wetlands: preliminary results

2020 ◽  
Vol 15 (2) ◽  
Author(s):  
Alberto Barco ◽  
Maurizio Borin
Keyword(s):  
Nitrogen Uptake ◽  
Root Length ◽  
Ornamental Plants ◽  
Water Bodies ◽  
Treatment Wetlands ◽  
Acorus Calamus ◽  
Mentha Aquatica ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Floating Treatment Wetlands

Floating treatment wetlands (FTWs) represent a novel ecotechnology for the treatment of different types of wastewaters in natural or artificial water bodies, through the use of traditional rooted emergent macrophyte species supported by floating rafts. Although many studies have reported the treatment performances of FTWs, showing an excellent aptitude for removing nutrients, heavy metals as well as suspended solids, the investigation of vegetation has not received much attention up to now, especially for herbaceous ornamental plant species that could form an interesting opportunity to improve water quality and the esthetic-ornamental value of urban water bodies. For this reason, a pilot scale FTW was installed in Northern Italy to assess the growth performances of eleven wetland species having ornamental features: Canna indica L., Pontederia cordata L., Thalia dealbata Fraser ex Roscoe, Acorus calamus L., Juncus effusus L., Iris laevigata L., Mentha aquatica L., Oenanthe javanica (Blume) DC., Caltha palustris L., Sparganium erectum L. and Zantedeschia aetiopica (L.) Srengel. For these species, a suitability index was elaborated that considers plant survivability, above-mat biomass production, nitrogen uptake, root length and root-shoot ratio. On this basis, the results obtained clearly indicated that C. indica, P. cordata and T. dealbata were the most suitable species for FTW due to their high vigor and colonization of the floating mats (1638.9 g m–2, 483.4 g m–2, 566.1 g m–2 of above-mat dry biomass, respectively; 38.8 cm, 62.0 cm, 43.8 cm root length, respectively; 0.8, 0.9, 1.2 root-shoot ratio, respectively), survival (100%), nitrogen uptake (15.1 g m–2, 15.0 g m–2, 15.7 g m–2 respectively). On the contrary, A. calamus, S. erectum and Z. aetiopica did not present adequate features for use in FTWs.

scholarly journals Sea Level Rise Effect on Groundwater Rise and Stormwater Retention Pond Reliability

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1129 ◽  
Author(s):  
Rahman Davtalab ◽  
Ali Mirchi ◽  
Rebecca J. Harris ◽  
Mark X. Troilo ◽  
Kaveh Madani
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Peak Flow ◽  
Coastal Areas ◽  
Groundwater Table ◽  
Retention Pond ◽  
Retention Ponds ◽  
Increased Risk ◽  
Study Results ◽  
Stormwater Retention

The coastal areas of Florida, United States, are exposed to increasing risk of flooding due to sea level rise as well as severe hurricanes. Florida regulations suggest constructing stormwater retention ponds as an option to retain excess runoff generated by the increased impervious area and to protect the environment by reducing pollutants from new developments. Groundwater level rise can significantly lower the soil storage capacity and infiltration at retention ponds, in turn, reducing the pond’s capacity to capture consecutive storms due to longer pond volume recovery time. Partial groundwater inundation can affect retention ponds’ ability to decrease peak flow rates and keep the post-development outflow lower than or equal to pre-development conditions. In this paper, the reliability and performance of a retention pond near Tampa Bay, Florida, was evaluated under sea level rise conditions. An integrated surface water and groundwater model was developed, and the groundwater table was projected for future conditions as a function of sea level rise. The results showed that sea level rise could increase the seasonal high water elevation of the retention pond up to 40 cm by mid-21st century. This increase lowered the reliability of the retention pond by about 45%. The pond failed to recover the designed treatment volume within required 72 h because of the high groundwater table, increasing the risk of pollutant discharge. Furthermore, the peak flow and volume of runoff significantly increased under sea level rise and associated groundwater table rise conditions. The study results suggest that it is imperative to consider future sea level rise conditions in stormwater design in low-lying coastal areas of Florida and around the world to prevent poor pond performance and increased risk of flooding in the future.

scholarly journals Irrigation Pond Characterization and Analysis: Impact of Weather and Management

2010 ◽  
Vol 28 (4) ◽  
pp. 224-234
Author(s):  
Laurie J. Fox ◽  
Paul C. Struik ◽  
Bonnie L. Appleton ◽  
Jerzy E. Nowak
Keyword(s):  
Water Depth ◽  
Management Practices ◽  
Golf Club ◽  
Retention Ponds ◽  
N Concentration ◽  
Virginia Beach ◽  
Nitrogen Concentrations ◽  
Average Water ◽  
The Impact ◽  
Stormwater Retention

Abstract Weather and management practices were monitored to assess the impact on water quality at four stormwater retention ponds used for irrigation. Two retention ponds were located at Bayville Golf Club (BGC) in Virginia Beach, VA, and two were located at Knotts Creek Nursery (KCN) in Suffolk, VA. Total dissolved N concentrations were examined at increasing depths and over time at the pond inflows and middles. Multiple fertilizer products with variable analyses were applied more frequently at BGC, but N concentrations were consistently higher at KCN. In 2002, a drought year, water temperatures fluctuated little over the season or with depth, regardless of location. N concentration ranges were 1.0—3.5 mg·liter−1 (ppm) at BGC and 2.5—6.0 at KCN. Nitrogen concentrations fluctuated as water depth increased. In 2003 rainfall was above average. Water temperatures fluctuated more over the season than in 2002 and with increasing depth. N concentration ranges were 0.75—4.2 mg·liter−1 (ppm) at BGC and 0.5—6.0 at KCN; and were consistent as water depth increased. Both water temperatures and N concentrations fluctuated dramatically at the inflow locations compared to the middles of the ponds.

scholarly journals Effect of baffles on the hydraulic performance of sediment retention ponds

2016 ◽  
Vol 75 (9) ◽  
pp. 1991-1996
Author(s):  
Sher Khan ◽  
Bruce W. Melville ◽  
Mudasser Muneer Khan ◽  
Muhammad Shoaib ◽  
Asaad Shamseldin
Keyword(s):  
Physical Model ◽  
Residence Time ◽  
Hydraulic Performance ◽  
Large Area ◽  
Sediment Retention ◽  
Retention Pond ◽  
Retention Ponds ◽  
Sediment Retention Ponds

An investigation of the effect of baffles on retention pond performance using a physical model of an existing sediment retention pond is presented. Analysis of residence time (RTD curves) was used to compare the hydraulic performance of different arrangements of baffles in the pond. Five different arrangements for the design of baffles were studied. The results show that placing a single baffle to deflect the influent to a sediment retention pond does not improve pond performance; rather, it stimulates short-circuiting. This is contradictory to the literature and is considered to be a consequence of the model pond incorporating sloping walls, which is a novel aspect of this study. Most of the previous studies have neglected the effects of battered walls. Conversely, the inclusion of more than two baffles was found to increase the hydraulic performance. The results reported here are limited to small and narrow ponds where a large portion of the pond is batter (i.e. made up of sloping walls). For large area ponds, batter effects may be negligible and are likely to be different from those reported here.

Sign in / Sign up

Export Citation Format

Share Document