System design and treatment efficiency of a surface flow constructed wetland receiving runoff impacted stream water

2012 ◽  
Vol 65 (3) ◽  
pp. 525-532 ◽  
Author(s):  
M. C. Maniquiz ◽  
J. Y. Choi ◽  
S. Y. Lee ◽  
C. G. Kang ◽  
G. S. Yi ◽  
...  

This study reported the efficiency of a free water surface flow constructed wetland (CW) system that receives runoff impacted stream water from a forested and agricultural watershed. Investigations were conducted to examine the potential effect of hydraulic fluctuations on the CW as a result of storm events and the changes in water quality along the flow path of the CW. Based on the results, the incoming pollutant concentrations were increased during storm events and greater at the near end of the storm than at the initial time of storm. A similar trend was observed to the concentrations exiting the CW due to the wetland being a relatively small percentage of the watershed (<0.1%) that allowed delays in runoff time during storm events. The concentrations of most pollutants were significantly reduced (p < 0.05) except for nitrate (p = 0.5). Overall, this study suggests that the design of the system could feasibly function for the retention of most pollutants during storm events as the actual water quality of the outflow was significantly better by 21–71% than the inflow and the levels of pollutants were reduced to appreciable levels.

2012 ◽  
Vol 65 (1) ◽  
pp. 119-126 ◽  
Author(s):  
M. C. Maniquiz ◽  
S. Y. Lee ◽  
J. Y. Choi ◽  
S. M. Jeong ◽  
L. H. Kim

The efficiency of a free water surface flow constructed wetland (CW) in treating agricultural discharges from stream was investigated during storm and non-storm events between April and December, 2009. Physico-chemical and water quality constituents were monitored at five sampling locations along the flow path of the CW. The greatest reduction in pollutant concentration was observed after passing the sedimentation zone at approximately 4% fractional distance from the inflow. The inflow hydraulic loading, flow rates and pollutant concentrations were significantly higher and variable during storm events than non-storm (baseflow) condition (p <0.001) that resulted to an increase in the average pollutant removal efficiencies by 10 to 35%. The highest removal percentages were attained for phosphate (51 ± 22%), ammonium (44 ± 21%) and phosphorus (38 ± 19%) while nitrate was least effectively retained by the system with only 25 ± 17% removal during non-storm events. The efficiency of the system was most favorable when the temperature was above 15 °C (i.e., almost year-round except the winter months) and during storm events. Overall, the outflow water quality was better than the inflow water quality signifying the potential of the constructed wetland as a treatment system and capability of improving the stream water quality.


2018 ◽  
Vol 13 (4) ◽  
pp. 764-770 ◽  
Author(s):  
T. M. Adyel ◽  
M. R. Hipsey ◽  
C. Oldham

Abstract This study assessed the significance of a multi-functional and multi-compartment constructed wetland (CW) implemented to restore a degraded urban waterway in Western Australia. The wetland was initially constructed as a surface flow system, then modified through the incorporation of the additional laterite-based subsurface flow system, with the potential for operation of a recirculation scheme and groundwater top-up during low water flows in summer. The CW performance was assessed by comparing nitrogen (N) and phosphorus (P) attenuation during base flow, high flow and episodic storm flow conditions. The performance varied from approximately 41% total nitrogen (TN) and 66% total phosphorus (TP) loads reduction during storm events, increasing up to 62% TN and 99% TP during low flow and summer recirculation periods. In overall, the CW attenuated about 45% TN and 65% TP loads from being delivered to the downstream sensitive river between 2009 and 2015. The CW design proved to be not only highly effective at reducing nutrient loads, but also improved the ecological services of the urban waterway by providing a diverse area for habitat and recreational activities.


2021 ◽  
Vol 9 (5) ◽  
pp. 1365-1375
Author(s):  
Rohaya Alias ◽  
Nur Asmaliza Mohd Noor ◽  
Lariyah Mohd Sidek ◽  
Anuar Kasa

2020 ◽  
Author(s):  
Linda Grinberga ◽  
Ainis Lagzdins

<p>This study includes water quality monitoring data obtained since June, 2014 at the farm located in the middle part of Latvia. The water treatment system with two separate constructed wetlands was established to improve water quality in agricultural area. A surface flow constructed wetland received drainage runoff from the agricultural catchment basin. A subsurface flow constructed wetland was implemented to retain nutrients from the surface runoff collected in the area of impermeable pavements of the farmyard. As there are no other specific calculations recommended for the designing of constructed wetlands in Latvia, both wetlands were calculated basing on the surface area of the constructed wetland/catchment area ratio. The surface area of the subsurface flow constructed wetland was deigned by 1.2% of the catchment area and the ratio was 0.5 % for the surface flow constructed wetland.</p><p>Water samples were collected manually by grab sampling method once or twice per month basing on a flowrate. Water quality parameters such as total suspended solids (TSS), nitrate-nitrogen (NO3-N), ammonium-nitrogen (NH4-N), total nitrogen (TN), orthophosphate-phosphorus (PO4-P), and total phosphorus (TP), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) were analysed to monitor the performance of both wetlands. The concentrations at the inlet and outlet were compared to evaluate the efficiency of the water treatment.</p><p>The concentrations of NO3-N, NH4-N and TN were reduced on average by 21 %, 35 % and 20 %, respectively for the surface flow constructed wetland. PO4-P and TP concentrations were reduced on average by 31 % and 45 %, respectively for the surface flow constructed wetland. Total suspended solids were reduced by 17% at the outlet of the surface flow constructed wetland. However, in some cases, an increase in nutrient concentrations in water leaving the wetland was observed. The study showed the constant reduction of the PO4-P and TP concentrations 82 % and 83 %, respectively in the subsurface flow constructed wetland. The concentrations of NO3-N, NH4-N and TN were reduced on average by 14 %, 66 % and 53 %, respectively for the subsurface flow constructed wetland. BOD and COD reduction on average by 93 % and 83 %, respectively in for the subsurface flow constructed wetland indicated the ability of the treatment system to be adapted for wastewater treatment with high content of organic matter under the given climate conditions. This study outlined that the farmyards should receive a special attention regarding surface runoff management.</p>


2009 ◽  
Vol 76 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
E. A. Wolyniak ◽  
B. R. Hargreaves ◽  
K. L. Jellison

ABSTRACT Cryptosporidium is a genus of waterborne protozoan parasites that causes significant gastrointestinal disease in humans. These parasites can accumulate in environmental biofilms and be subsequently released to contaminate water supplies. Natural microbial assemblages were collected each season from an eastern Pennsylvania stream and used to grow biofilms in laboratory microcosms in which influx, efflux, and biofilm retention were determined from daily oocyst counts. For each seasonal biofilm, oocysts attached to the biofilm quickly during oocyst dosing. Upon termination of oocyst dosing, the percentage of oocysts retained within the biofilm decreased to a new steady state within 5 days. Seasonal differences in biofilm retention of oocysts were observed. The spring biofilm retained the greatest percentage of oocysts, followed (in decreasing order) by the winter, summer, and fall biofilms. There was no statistically significant correlation between the percentage of oocysts attached to the biofilm and (i) any measured stream water quality parameter (including temperature, pH, conductivity, and dissolved organic carbon concentration) or (ii) experimental temperature. Seasonal differences in oocyst retention persisted when biofilms were tested with stream water from a different season. These data suggest that seasonal variation in the microbial community and resulting biofilm architecture may be more important to oocyst transport in this stream site than water quality. The biofilm attachment and detachment dynamics of C. parvum oocysts have implications for public health, and the drinking water industry should recognize that the potential exists for pathogen-free water to become contaminated during the distribution process as a result of biofilm dynamics.


2011 ◽  
Vol 121-126 ◽  
pp. 3072-3076
Author(s):  
Chun Yi Wu ◽  
Yu Tung Fu ◽  
Zong Han Yang ◽  
Chih Ming Kao ◽  
Yao Ting Tu

In 2007, a 2.8-ha multi-function constructed wetland was successfully built in Pingtung County, Taiwan to improve the water quality of local stream and ecosystem of the surrounding environment. The mean inflow rate was approximately 1,350 m3/day. The major influents of the wetland come from the local drainage ditches and streams mainly containing returned water from upstream farmlands and secondary wastewater from hog farms located in the upper catchment of the wetland. Thus, the influents contain moderate to high concentrations of organics and nutrients. The mean measured hydraulic loading rate, hydraulic retention time, water depth, and total volume of wetland system were 0.1 m/day, 5.5 days, 0.7 m, and 7,800 m3, respectively. In this study, water, sediment, and plant samples were collected and analyzed quarterly for each wetland basin during the two-year investigation period. Results show that more than 77% of total coliforms (TC), 78% of biochemical oxygen demand (BOD), 88% of total nitrogen (TN), and 96% of ammonia nitrogen were removed via the constructed wetland system. Thus, the wetland system has a significant effect on water quality improvement and is able to remove most of the pollutants from the local stream through natural attenuation mechanisms. Except for stream water quality improvement and rehabilitating the natural ecosystem, this wetland also offers more water assessable eco-ponds and eco-gardens for public. This constructed wetland has become one of the most successful multi-function constructed wetlands in Taiwan.


2015 ◽  
Vol 73 (6) ◽  
pp. 1483-1491 ◽  
Author(s):  
Siping Niu ◽  
Kisoo Park ◽  
Jing Cheng ◽  
Youngchul Kim

An investigation on free water surface wetland, which has an area of 0.23 ha and is employed to control the non-point source pollution from a watershed of 7.4 ha, was carried out to examine how the WQvr (the ratio of stormwater inflow volume to water quality volume (WQv)) affects the wetland treatment performance. As stormwater went through the wetland, TSS (total suspended solids), TCOD (total chemical oxygen demand), TN (total nitrogen) and TP (total phosphorus) were reduced by 85%, 57%, 6% and 68%, on average, respectively. Increase in the WQvr resulted in a decrease in the reduction efficiencies of TSS, TCOD and TP, but a slight increase in TN removal. WQv was identified as a useful parameter for the design of stormwater wetlands, as this volumetric design approach overcomes the variation in flow rate and pollutant concentrations with respect to time and rainfall conditions. However, the design goal of 80% TSS reduction was not accomplished as inflow water volume equal to designed WQv. On the other hand, it was found that TCOD and TP reduction could also be considered as wetland design goals together with TSS. However, TN reduction did not show any significant relationship with the WQv.


Sign in / Sign up

Export Citation Format

Share Document