Investigation of a fiber optic surface plasmon spectroscopy in conjunction with conductivity as an in situ method for simultaneously monitoring changes in dissolved organic carbon and salinity in coastal waters

The Analyst ◽  
2011 ◽  
Vol 136 (20) ◽  
pp. 4350 ◽  
Author(s):  
Yoon-Chang Kim ◽  
Jeffrey A. Cramer ◽  
Karl S. Booksh
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Surface Plasmon ◽  
Coastal Waters ◽  
Fiber Optic ◽  
In Situ Method ◽  
Surface Plasmon Spectroscopy

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

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 859
Author(s):  
Suzanne R. Jacobs ◽  
Björn Weeser ◽  
Mariana C. Rufino ◽  
Lutz Breuer
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Stream Water ◽  
Visible Spectrum ◽  
Mobile Sensor ◽  
Stream Water Quality ◽  
High Resolution Data ◽  
Diurnal Patterns ◽  
Solute Dynamics

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.

In situ dissolved organic carbon (DOC) release by submerged macrophyte–epiphyte communities in southern Quebec lakes

2009 ◽  
Vol 66 (9) ◽  
pp. 1522-1531 ◽  
Author(s):  
M. Demarty ◽  
Y. T. Prairie
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Myriophyllum Spicatum ◽  
Dry Weight ◽  
Release Rates ◽  
Doc Production ◽  
Epiphyte Communities ◽  
Benthic Chambers ◽  
Freshwater Macrophyte

We studied the in situ release of dissolved organic carbon (DOC) by growing a submerged freshwater macrophyte–epiphyte complex. Incubations with benthic chambers in five southeastern Quebec lakes show a net DOC production for different communities of Myriophyllum spicatum and Potamogeton spp. Daytime DOC release rates range from undetectable to 9.7 mg C·m–2·h–1. Although DOC release was restricted to daylight hours and thus suggestive of a photosynthesis-related process, we found no strong link between DOC release rates and concurrent illumination or temperature. We found no difference in DOC release rates between the three main colonizing species of the studied region. The overall mean DOC release rate was 4.57 mg C·m–2·h–1 (standard deviation (SD), ±0.65) or 56 µg C·g dry weight–1·h–1 (SD, ±8), which we suggest can be used for extrapolations at the lake scale.

scholarly journals Tracing terrestrial versus marine sources of dissolved organic carbon in a coastal bay using stable carbon isotopes

2020 ◽  
Vol 17 (1) ◽  
pp. 135-144 ◽  
Author(s):  
Shin-Ah Lee ◽  
Tae-Hoon Kim ◽  
Guebuem Kim
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Matter ◽  
Dissolved Organic Carbon ◽  
Coastal Waters ◽  
High Salinity ◽  
Carbon Isotopic Composition ◽  
C3 Plants ◽  
Stable Carbon ◽  
Coastal Bay

Abstract. The sources of dissolved organic matter (DOM) in coastal waters are diverse, and they play different roles in the biogeochemistry and ecosystems of the ocean. In this study, we measured dissolved organic carbon (DOC) and nitrogen (DON), the stable carbon isotopic composition of dissolved organic carbon (δ13C-DOC), and fluorescent dissolved organic matter (FDOM) in coastal bay waters surrounded by large cities (Masan Bay, Republic of Korea) to determine the different DOM sources in this region. The surface seawater samples were collected in two sampling campaigns (August 2011 and August 2016). The salinities were in the range of 10–21 in 2011 and 25–32 in 2016. In 2011, excess DOC was observed in high-salinity (16–21) waters; the excess DOC source was found to be mainly from marine autochthonous production according to the δ13C-DOC values (−23.7 ‰ to −20.6 ‰), the higher concentrations of protein-like FDOM, and the lower DOC∕DON (C∕N) ratios (8–15). In contrast, excess DOC observed in high-salinity waters in 2016 was characterized by low FDOM, more depleted δ13C values (−28.8 ‰ to −21.1 ‰), and high C∕N ratios (13–45), suggesting that the source of excess DOC is terrestrial C3 plants by direct land–seawater interactions. Our results show that multiple DOM tracers such as δ13C-DOC, FDOM, and C∕N ratios are powerful for determining different sources of DOM occurring in coastal waters.

scholarly journals In-situ fluorescence spectroscopy indicates total bacterial abundance and dissolved organic carbon

2020 ◽  
Vol 738 ◽  
pp. 139419 ◽  
Author(s):  
James P.R. Sorensen ◽  
Mor Talla Diaw ◽  
Abdoulaye Pouye ◽  
Raphaëlle Roffo ◽  
Djim M.L. Diongue ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Fluorescence Spectroscopy ◽  
Dissolved Organic Carbon ◽  
Bacterial Abundance ◽  
Total Bacterial Abundance

Optical in-situ sensors capture dissolved organic carbon (DOC) dynamics after prescribed fire in high-DOC forest watersheds

2019 ◽  
Vol 28 (10) ◽  
pp. 761 ◽  
Author(s):  
Christopher I. Olivares ◽  
Wenbo Zhang ◽  
Habibullah Uzun ◽  
Cagri Utku Erdem ◽  
Hamed Majidzadeh ◽  
...  
Keyword(s):  
South Carolina ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Optical Sensors ◽  
Prescribed Fire ◽  
Second Order ◽  
In Situ Sensors ◽  
Forest Watersheds ◽  
Doc Load

Fires alter terrestrial dissolved organic carbon (DOC) exports into water, making reliable post-fire DOC monitoring a crucial aspect of safeguarding drinking water supply. We evaluated DOC optical sensors in a pair of prescribed burned and unburned first-order watersheds at the Santee Experimental Forest, in the coastal plain forests of South Carolina, and the receiving second-order watershed during four post-fire storm DOC pulses. Median DOC concentrations were 30 and 23mgL−1 in the burned and unburned watersheds following the first post-fire storm. Median DOC remained high during the second and third storms, but returned to pre-fire concentrations in the fourth storm. During the first three post-fire storms, sensor DOC load in the burned watershed was 1.22-fold higher than in the unburned watershed. Grab samples underestimated DOC loads compared with those calculated using the in-situ sensors, especially for the second-order watershed. After fitting sensor values with a locally weighted smoothing model, the adjusted sensor values were within 2mgL−1 of the grab samples over the course of the study. Overall, we showed that prescribed fire can release DOC during the first few post-fire storms and that in-situ sensors have adequate sensitivity to capture storm-related DOC pulses in high-DOC forest watersheds.

Sign in / Sign up

Export Citation Format

Share Document