scholarly journals Technical Note: Assessing a 24/7 solution for monitoring water quality loads in small river catchments

2011 ◽  
Vol 15 (10) ◽  
pp. 3093-3100 ◽  
Author(s):  
P. Jordan ◽  
R. Cassidy
Keyword(s):  
Point Source ◽  
Integrated Approach ◽  
Technical Note ◽  
Low Flow ◽  
Phosphorus Concentration ◽  
Storm Events ◽  
Concentration Data ◽  
High Discharge ◽  
Sediment Loads ◽  
Source Signals

Abstract. Quantifying nutrient and sediment loads in catchments is difficult owing to diffuse controls related to storm hydrology. Coarse sampling and interpolation methods are prone to very high uncertainties due to under-representation of high discharge, short duration events. Additionally, important low-flow processes such as diurnal signals linked to point source impacts are missed. Here we demonstrate a solution based on a time-integrated approach to sampling with a standard 24 bottle autosampler configured to take a sample every 7 h over a week according to a Plynlimon design. This is evaluated with a number of other sampling strategies using a two-year dataset of sub-hourly discharge and phosphorus concentration data. The 24/7 solution is shown to be among the least uncertain in estimating load (inter-quartile range: 96% to 110% of actual load in year 1 and 97% to 104% in year 2) due to the increased frequency raising the probability of sampling storm events and point source signals. The 24/7 solution would appear to be most parsimonious in terms of data coverage and certainty, process signal representation, potential laboratory commitment, technology requirements and the ability to be widely deployed in complex catchments.

scholarly journals Technical Note: Demonstrating a 24/7 solution for monitoring water quality loads in rivers

2011 ◽  
Vol 8 (3) ◽  
pp. 5035-5050
Author(s):  
P. Jordan ◽  
R. Cassidy
Keyword(s):  
Point Source ◽  
Integrated Approach ◽  
Technical Note ◽  
Low Flow ◽  
Phosphorus Concentration ◽  
Storm Events ◽  
Concentration Data ◽  
High Discharge ◽  
Sediment Loads ◽  
Source Signals

Abstract. Quantifying nutrient and sediment loads in catchments is difficult owing to diffuse controls related to storm hydrology. Coarse sampling and interpolation methods are prone to very high uncertainties due to under-representation of high discharge, short duration events. Additionally, important low-flow processes such as diurnal signals linked to point source impacts are missed. Here we demonstrate a solution based on a time-integrated approach to sampling with a standard 24 bottle autosampler configured to take a sample every 7 h over a week. This is evaluated with a number of other sampling strategies using a two-year dataset of sub-hourly discharge and phosphorus concentration data. The 24/7 solution is shown to be the least uncertain in estimating load (inter-quartile range is 96 % to 110 % of actual load in year 1 and 97 % to 104 % in year 2) due to the increased frequency raising the probability of sampling storm events and point source signals. The 24/7 solution would appear to be most parsimonious in terms of technology requirements, the ability to be widely deployed and to represent important nutrient transfer processes in complex catchments.

Nitrogen and phosphorus in the Vistula River, Poland -- changes from source to mouth

1994 ◽  
Vol 30 (5) ◽  
pp. 177-186 ◽  
Author(s):  
Karin Sundblad ◽  
Andrzej Tonderski ◽  
Jacek Rulewski
Keyword(s):  
Central Region ◽  
Northern Region ◽  
Point Sources ◽  
Nutrient Loss ◽  
Phosphorus Concentration ◽  
Nitrogen And Phosphorus ◽  
Concentration Data ◽  
Diffuse Sources ◽  
Vistula River ◽  
South Central

Nitrogen and phosphorus concentration data representing samples collected once a month for nine months at 13 locations along the Vistula River are considered in a preliminary discussion of the sources of the nutrients transported to the Baltic Sea. Concentrations in relation to flow data indicated substantial differences between subbasins. Based on those differences, on the area-specific nutrient loss for a six-month period and on the wastewater discharge in each subbasin, four regions could be recognized in the river basin: i) the southern region with a large impact of point sources, ii) the south central region, where diffuse sources seemed to be of major importance, iii) the north central region with a combined effect of point and diffuse sources, and retention in two reservoirs, iv) the northern region where point sources seemed to be the dominating source, at least for phosphorus. Our results illustrate the importance of differences in phosphorus retention between the basins. Long-term retention along the course of the river, particularly in the two reservoirs, must be estimated to allow proper source apportionment in the Vistula basin. Concentration decreases in the Wloclawek Reservoir varied between 44 and 68% for P, and 11 to 37% for N, in the months with significant retention. In some months, however, concentrations increased, indicating a release of nutrients.

Water quality modeling in the watershed-based approach for waste load allocations

1998 ◽  
Vol 38 (10) ◽  
pp. 165-172 ◽  
Author(s):  
Ruochuan Gu ◽  
Mei Dong
Keyword(s):  
Water Quality ◽  
Point Source ◽  
Water Quality Modeling ◽  
Point Sources ◽  
Low Flow ◽  
Quality Analysis ◽  
Management Approach ◽  
Water Quality Control ◽  
Quality Modeling ◽  
Waste Load

The conventional method for waste load allocations (WLA) employs spatial-differentiation, considering individual point sources, and temporal-integration, using a constant flow, typically 7Q10 low flow. This paper presents a watershed-based seasonal management approach, in which non-point source as well as point sources are incorporated, seasonal design flows are used for water quality analysis, and WLA are performend in a watershed scale. The strategy for surface water quality modeling in the watershed-based approach is described. The concept of seasonal discharge management is discussed and suggested for the watershed-based approach. A case study using the method for the Des Moines River, Iowa, USA is conducted. Modeling considerations and procedure are presented. The significance of non-point source pollutant load and its impact on water quality of the river is evaluated by analyzing field data. A water quality model is selected and validated against field measurements. The model is applied to projections of future water quality situations under different watershed management and water quality control scenarios with respect to river flow and pollutant loading rate.

Non-point source pesticide removal by a mountainous wetland

2002 ◽  
Vol 46 (6-7) ◽  
pp. 199-206 ◽  
Author(s):  
C.M. Kao ◽  
J.Y. Wang ◽  
K.F. Chen ◽  
H.Y. Lee ◽  
M.J. Wu
Keyword(s):  
Water Quality ◽  
Point Source ◽  
Surface Water Quality ◽  
Storm Events ◽  
Agricultural Lands ◽  
Pesticide Removal ◽  
Nps Pollution ◽  
Natural Wetlands ◽  
Wetland System ◽  
Water Quality Deterioration

Non-point source (NPS) pollution is believed to be one of the major causes of impairment of water bodies. Among NPS pollution, agricultural NPS pollution is considered to be the largest single category resulting in water quality deterioration. Pesticides are some the most ubiquitous of these agricultural NPS pollutants. In this study, a mountainous wetland was selected to investigate the effects of the natural wetland system on the NPS pesticide (atrazine) removal to maintain the surface water quality. The selected wetland receives water from two unnamed creeks, which drain primarily upgradient agricultural lands. Wetland investigation and monitoring were conducted from November 1999 to March 2001. Major storm events and baseline water quality samples were analyzed. Field results indicate that the wetland was able to remove NPS atrazine flushed from the upgradient agricultural lands after the occurrence of storm events. Laboratory aerobic and anaerobic bioreactor experiments were conducted to evaluate the biodegradation of atrazine under the intrinsic conditions of the wetland system. Microbial enumeration was conducted for a quick screen of bacterial activity in the studied wetland. Results from the study suggest that the methanogenesis process was possibly the dominant biodegradation pattern, and atrazine can be degraded under reductive dechlorinating conditions when sufficient intrinsic organic matter was provided. Results from this study can provide us with further knowledge on pesticide removal mechanisms in natural wetlands and evaluate the role of wetlands in controlling pesticide pollutants from stormwater runoff.

scholarly journals A multi-functional and multi-compartment constructed wetland to support urban waterway restoration

2018 ◽  
Vol 13 (4) ◽  
pp. 764-770 ◽  
Author(s):  
T. M. Adyel ◽  
M. R. Hipsey ◽  
C. Oldham
Keyword(s):  
Constructed Wetland ◽  
Flow System ◽  
Surface Flow ◽  
Base Flow ◽  
Low Flow ◽  
Nutrient Loads ◽  
Storm Events ◽  
Flow Conditions ◽  
Storm Flow ◽  
Diverse Area

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.

Comparison of the use of total phosphorus concentration and acetic acid soluble phosphorus concentration in petioles for assessing the phosphorus status of potato crops

1989 ◽  
Vol 29 (3) ◽  
pp. 433 ◽  
Author(s):  
NA Maier ◽  
KA Potocky-Pacay ◽  
CMJ Williams
Keyword(s):  
Acetic Acid ◽  
Total Phosphorus ◽  
Relative Yield ◽  
Coefficient Of Determination ◽  
Phosphorus Concentration ◽  
Concentration Data ◽  
Total Phosphorus Concentration ◽  
Soluble Phosphorus ◽  
Phosphorus Status ◽  
Potato Crops

We studied the effect of rate of applied phosphorus on total phosphorus concentration (17 sites) and acetic acid soluble phosphorus concentration (12 sites) in petioles of youngest fully expanded leaves of potatoes (cvv. Kennebec, Coliban and Exton) when their largest tubers were 5-10 mm long. We showed that the internal requirements for phosphorus are similar for the cvv. Kennebec and Coliban. Taken over all sites, mean total phosphorus concentrations and acetic acid soluble phosphorus concentrations ranged from 0.22 to 0.84% and 0.10 to 0.63%, respectively depending on phosphorus supply. For each site a coefficient of determination (r2) was calculated based on the mean total phosphorus concentration versus acetic acid soluble phosphorus concentration data for all treatments. The r2 values varied from 0.969 (site 14) to 0.997 (site 17). On the pooled data for all sites, the Cate-Nelson separation and the Mitscherlich and Smith-Dolby bent-hyperbola models were used to investigate the correlations between relative yield [(mean treatment yields/maximum treatment yie1d)x 100] and total phosphorus concentration (n = 16 1, 17 sites) and acetic acid soluble phosphorus concentration (n = 112, 12 sites) and to calculate the critical values. Depending on the model fitted the critical total phosphorus concentrations varied from 0.41 (r2 = 0.62) to 0.53% (r2 = 0.72). The critical acetic acid soluble phosphorus concentrations varied from 0.29 (r2 = 0.62) to 0.52% (r2 = 0.72). Critical concentration ranges of 0.41-0-53% for total phosphorus and 0.29-0.52% for acetic acid soluble phosphorus have been proposed to assist in the assessment of the phosphorus status of irrigated potato crops in South Australia. Based on sensitivity, reproducibility and sharpness of the transition zone between adequacy and deficiency we found no advantage in determining acetic acid soluble phosphorus concentration rather than total phosphorus concentration to assess the phosphorus status of potato plants.

scholarly journals Characterising phosphorus transfers in rural catchments using a continuous bank-side analyser

2007 ◽  
Vol 11 (1) ◽  
pp. 372-381 ◽  
Author(s):  
P. Jordan ◽  
A. Arnscheidt ◽  
H. McGrogan ◽  
S. McCormick
Keyword(s):  
Point Sources ◽  
Mitigation Measures ◽  
Data Series ◽  
Storm Events ◽  
Catchment Scale ◽  
Concentration Data ◽  
Monitoring Technology ◽  
Transfer Event ◽  
Discharge Data ◽  
Total Period

Abstract. A six-month series of high-resolution synchronous stream discharge and total phosphorus (TP) concentration data is presented from a 5 km2 agricultural catchment in the Lough Neagh basin, Northern Ireland. The data are hourly averages of 10-minute measurements using a new bankside, automatic, continuous monitoring technology. Three TP transfer "event-types" occur in this catchment: (1) chronic, storm independent transfers; (2) acute, storm dependent transfers; (3) acute, storm independent transfers. Event-type 2 transferred over 90% of the total 279 kg TP load in 39% of the total period; it corresponded to diffuse transfers from agricultural soils. Event-types 1 and 3, however, maintained the river in a highly eutrophic state between storm events and were characteristic of point source pollution, despite there being no major industrial or municipal point sources. Managing P transfers at the catchment scale requires a robust monitoring technology to differentiate between dynamic, multiple sources and associated event types and so enable a reliable assessment of the performance of mitigation measures, monitored at catchment outlets. The synchronous and continuous TP and discharge data series generated in this study demonstrate how this is possible.

scholarly journals Technical note: an interannual inversion method forcontinuous CO<sub>2</sub> data

2004 ◽  
Vol 4 (2) ◽  
pp. 477-484 ◽  
Author(s):  
R. M. Law
Keyword(s):  
Computational Cost ◽  
Technical Note ◽  
Inversion Method ◽  
Seasonal Cycles ◽  
Concentration Data ◽  
Sequential Method ◽  
Monthly Data ◽  
Hourly Data ◽  
Atmospheric Data ◽  
Comparable Quality

Abstract. A sequential synthesis inversion method is described to estimate CO2 sources from continuous atmospheric data. The sequential method makes the problem computationally feasible. The method is assessed using four-hourly synthetic concentration data generated from known sources. Multi-year mean sources and seasonal cycles are estimated with comparable quality as those from a traditional inversion of monthly mean data. Interannual variations in the estimated sources are closer to those of the known sources using the four-hourly data rather than monthly data. The computational cost of the basis function simulations can be reduced by generating responses that are only six months long. This does not significantly degrade the inversion results compared to using responses that are 12 months in length.

Hydraulic and treatment performance of pervious pavements under variable drying and wetting regimes

2011 ◽  
Vol 64 (8) ◽  
pp. 1692-1699 ◽  
Author(s):  
C. F. Yong ◽  
A. Deletic ◽  
T. D. Fletcher ◽  
M. R. Grace
Keyword(s):  
Suspended Solids ◽  
High Flow ◽  
Pollutant Removal ◽  
Low Flow ◽  
Storm Event ◽  
Stormwater Treatment ◽  
Storm Events ◽  
Treatment Technology ◽  
Porous Asphalt ◽  
Treatment Performance

Pervious pavements are an effective stormwater treatment technology. However, their performance under variable drying and wetting conditions have yet to be tested, particularly under a continuous time scale. This paper reports on the clogging behaviour and pollutant removal efficiency of three pervious pavement types over 26 accelerated years. These pavements were monolithic porous asphalt (PA), Permapave (PP) and modular Hydrapave (HP). Over a cycle of 13 days, the period of which was equivalent to the average annual Brisbane, Australia rainfall (1,200 mm), the pavements were randomly dosed with four different flows. Drying events of 3 h duration were simulated during each flow. Inflow and outflow samples were collected and analysed for Total Suspended Solids (TSS), Total Phosphorus (TP) and Total Nitrogen (TN). To evaluate the rate of clogging, a 1 in 5 year Brisbane storm event was simulated in the 6th, 8th, 12th, 16th, 20th and 24th week. Under normal dosing conditions, none of the pavements showed signs of clogging even after 15 years. However, under storm conditions, both PA and HP started to clog after 12 years, while PP showed no signs of clogging after 26 years. The drying and various flow events showed no effects in TSS removal, with all systems achieving a removal of approximately 100%. The average TP removal was 20% for all flows except for low flow, which had a significant amount of leaching over time. Leaching from TN was also observed during all flows except high flow. The TSS, TP and TN results observed during storm events were similar to that of high flow.

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