Technical Note: Field experiences using UV/VIS sensors for high-resolution monitoring of nitrate in groundwater

Huebsch, Manuela; Grimmeisen, Felix; Zemann, Moritz; Fenton, Owen; Richards, Karl G.; Jordan, Phillip; Sawarieh, Ali; Blum, Philipp; Goldscheider, Nico

doi:10.5194/hess-19-1589-2015

Cited by 38 publications

(25 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Few studies using UV-Vis spectrophotometers report the orientation of the sensor, and little guidance is provided by the manufacturers. The choice for a certain sensor orientation is often based on reducing biofouling and the settlement of sediment on the sensor window [45][46][47], while shielding from incoming UV radiation is rarely mentioned by researchers, e.g., [19]. There are no studies on the potential influence of exposure to sunlight on in situ UV-Vis measurements.…”

Section: Explanatory Variablesmentioning

confidence: 99%

“…In addition, the fouling of the sensor measurement windows can occur through the oxidation of iron or manganese by UV light [23] or biofouling [21,25,47,53]. Additionally, other substances in the water can interfere with the measurements, such as nitrite or bicarbonate [45]. Several studies mention that high turbidity values (>80 FTU [45], >300-450 FTU [54], >1000 NTU [52]) reduce the ability of the UV-Vis sensors to provide valid measurements for nitrate.…”

Section: Implications For the Use Of In Situ Uv-vis Sensorsmentioning

confidence: 99%

See 1 more Smart Citation

Diurnal Patterns in Solute Concentrations Measured with In Situ UV-Vis Sensors: Natural Fluctuations or Artefacts?

Jacobs

Weeser

Rufino

2020

Sensors

View full text Add to dashboard Cite

In situ spectrophotometers measuring in the UV-visible spectrum are increasingly used to collect high-resolution data on stream water quality. This provides the opportunity to investigate short-term solute dynamics, including diurnal cycling. This study reports unusual changes in diurnal patterns observed when such sensors were deployed in four tropical headwater streams in Kenya. The analysis of a 5-year dataset revealed sensor-specific diurnal patterns in nitrate and dissolved organic carbon concentrations and different patterns measured by different sensors when installed at the same site. To verify these patterns, a second mobile sensor was installed at three sites for more than 3 weeks. Agreement between the measurements performed by these sensors was higher for dissolved organic carbon (r > 0.98) than for nitrate (r = 0.43–0.81) at all sites. Higher concentrations and larger amplitudes generally led to higher agreement between patterns measured by the two sensors. However, changing the position or level of shading of the mobile sensor resulted in inconsistent changes in the patterns. The results of this study show that diurnal patterns measured with UV-Vis spectrophotometers should be interpreted with caution. Further work is required to understand how these measurements are influenced by environmental conditions and sensor-specific properties.

show abstract

Section: Explanatory Variablesmentioning

confidence: 99%

Section: Implications For the Use Of In Situ Uv-vis Sensorsmentioning

confidence: 99%

Diurnal Patterns in Solute Concentrations Measured with In Situ UV-Vis Sensors: Natural Fluctuations or Artefacts?

Jacobs

Weeser

Rufino

2020

Sensors

View full text Add to dashboard Cite

show abstract

“…The added value of high-frequency monitoring is its ability to distinguish between fast and slow flow components (see Poulsen et al, 2015b;Shreshta et al, 2013;Rozemeijer et al, 2010aRozemeijer et al, , 2012. High-frequency monitoring has also stimulated the development of new approaches to characterize the transient nature of travel time distributions (Van der Velde et al, 2010;Botter et al, 2011;Hrachowitz et al, 2015).…”

Section: Monitoring Objectivesmentioning

confidence: 99%

“…A number of studies (e.g. Rozemeijer et al, 2010c;Cassidy and Jordan, 2011;Jordan et al, 2013;Huebsch et al, 2015) compare several sampling instruments and monitoring strategies (Table 2). Various continuous monitoring methods, in particular those described in the papers presented in this special issue, are listed in Table 2.…”

Section: Monitoring Equipmentmentioning

confidence: 99%

High resolution monitoring of nutrients in groundwater and surface waters: process understanding, quantification of loads and concentrations and management applications

Geer¹,

Kronvang²,

Broers³

2016

Preprint

View full text Add to dashboard Cite

Abstract. Four sessions on "Monitoring Strategies: temporal trends in groundwater and surface water quality and quantity" at the EGU-conferences in 2012, 2013, 2014 and 2015 and a special issue of HESS form the background for this overview of the current state of high resolution monitoring of nutrients. The overview includes a summary of technologies applied in high frequency monitoring of nutrients in the special issue. Moreover, we present a new assessment of the objectives behind high frequency monitoring as classified into three main groups: (i) improved understanding of the underlying hydrological, chemical and biological processes (PU); (ii) quantification of true nutrient concentrations and loads (Q); (iii) operational management, including evaluation of the effects of mitigation measures (M). The contributions in the special issue focus on the implementation of high frequency monitoring within the broader context of policy making and management in Europe for support of EU Directives such as the Water Framework Directive, the Groundwater Directive and the Nitrate Directive. The overview presented based on the special issue and the presentations at the four EGU sessions enabled us to highlight the typical objectives encountered in the application of high frequency monitoring to support EU Directives, to assess the temporal and spatial scales and to reflect on future developments and research needs in this growing field of expertise.

show abstract

“…They are often used in wastewater drainage systems for a fast and simple evaluation of wastewater quality (Brito et al, 2014;Gamerith et al, 2011;Rieger et al, 2004;Rieger et al, 2006;Rieger et al, 2008). They have been used to estimate turbidity, dissolved organic carbon (DOC), total organic carbon (TOC) and nitrates (NO 3 -N) in streams at a temporal resolution as high as several minutes (Avagyan et al, 2014;Bass et al, 2011;Grayson and Holden, 2012;Huebsch et al, 2014;Huebsch et al, 2015;Jeong et al, 2012;Koehler et al, 2009;López-Kleine and Torres, 2014;Strohmeier et al, 2013;Waterloo et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

In situand high frequency monitoring of suspended sediment properties using a spectrophotometric sensor

et al. 2016

View full text Add to dashboard Cite

It is well known that sediment properties, including sediment-associated chemical constituents and sediment physical properties, can exhibit significant variations within and between storm runoff events. However, the number of samples included in suspended sediment studies is often limited by time-consuming and expensive laboratory procedures after stream water sampling. This restricts high frequency sampling campaigns to a limited number of events and reduces accuracy when aiming to estimate fluxes and loads of sediment-associated chemical constituents. In this study, we address the potential of a portable ultraviolet-visible spectrophotometer (220-730 nm) to estimate suspended sediment properties in a resource efficient way. Several field deployable spectrophotometers are currently available for in-stream measurements of environmental variables at high temporal resolution. These instruments have primarily been developed and used to quantify solute concentrations (e.g. dissolved organic carbon and NO 3 -N), total concentrations of dissolved and particulate forms (e.g. total organic carbon) and turbidity. Here we argue that light absorbance values can be calibrated to estimate sediment properties. We present light absorbance data collected at 15-min intervals in the Weierbach catchment (NW Luxembourg, 0.45 km 2 ) from December 2013 to January 2015. In this proof-of-concept study, we performed a local calibration using suspended sediment loss-on-ignition (LOI) measurements as an example of suspended sediment property. We assessed the performance of several regression models that relate light absorbance measurements with the percentage weight LOI. The MM-robust regression method presented the lowest standard error of prediction (0.48%) and was selected for calibration (adjusted r 2 = 0.76 between observed and predicted values). The model was then used to predict LOI during a storm runoff event in December 2014. This study demonstrates that spectrophotometers can be used to estimate suspended sediment properties at high temporal resolution and for long-time spans in a simple, non-destructive and affordable manner.

show abstract

Technical Note: Field experiences using UV/VIS sensors for high-resolution monitoring of nitrate in groundwater

Cited by 38 publications

References 32 publications

Diurnal Patterns in Solute Concentrations Measured with In Situ UV-Vis Sensors: Natural Fluctuations or Artefacts?

Diurnal Patterns in Solute Concentrations Measured with In Situ UV-Vis Sensors: Natural Fluctuations or Artefacts?

High resolution monitoring of nutrients in groundwater and surface waters: process understanding, quantification of loads and concentrations and management applications

In situand high frequency monitoring of suspended sediment properties using a spectrophotometric sensor

Contact Info

Product

Resources

About