Impacts of sampling frequency on the estimation accuracy of exceedance for suspended solids and nitrates in streams in small to medium-sized watersheds

Qi, Junyu; Li, Sheng; Benoy, Glenn; Xing, Zisheng; Gao, Lin; Meng, Fan‐Rui

doi:10.1016/j.hydroa.2022.100139

Cited by 1 publication

(2 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, they found that high frequency sampling improved estimates of residence time and volumetric removal rates, especially if the bioreactor has long hydraulic retention time and significant lag between inlet and outlet. Similarly, Qi et al (2022) also found that lower frequency sampling could underestimate pollutant concentrations by missing large events. However, they also state that high frequency sampling can also result in positive relative bias due to overrepresentation of large events.…”

Section: Study Limitationsmentioning

confidence: 90%

“…While results from this study show promise for using IBRs to improve nitrogen treatment in residential sub-watersheds served by septic systems, this study was not without its limitations. Past studies (Maxwell et al 2020;Qi et al 2022) recommend high frequency sampling to improve efforts to quantify water quality parameters. Maxwell et al (2020) found that concentration reductions of nitrate varied by up to 25% within a single event.…”

Section: Study Limitationsmentioning

confidence: 99%

See 1 more Smart Citation

Quantifying Nitrogen Treatment by an In-stream Bioreactor in a Watershed Served by Septic Systems

Iverson,

Humphrey,

O’Driscoll

et al. 2024

Environ. Process.

View full text Add to dashboard Cite

Septic systems are potentially significant sources of nitrogen to groundwater and surface water. In-stream practices, such as in-stream bioreactors (IBRs), that promote or enhance nitrogen treatment are promising solutions to reduce nitrogen loads to nutrient-sensitive water. More work is needed to evaluate the efficiency of IBRs in new applications, such as residential sub-watersheds with a high-density of septic systems. The goal of this study was to quantify nitrogen treatment by an in-stream bioreactor (IBR) during baseflow conditions. The IBR was constructed in March 2017 when approximately 1 m of streambed sediment was excavated and backfilled with 0.75 m of woodchips capped by 0.2 m of rotary-kiln, expanded slate and boulder-sized riprap. Samples were collected monthly from July 2017 – March 2019 including IBR inflow, monitoring ports within the IBR, groundwater seeps draining to the IBR, and IBR outflow. Water samples were analyzed for total dissolved nitrogen (TDN), nitrate, ammonium, dissolved organic carbon, chloride, and nitrate isotopic fractionation. The IBR reduced the median concentration of TDN and nitrate by 40% and 77%, respectively. The median mass removal of TDN and nitrate was 26 and 5.2 g day− 1, respectively. Nitrogen-chloride ratios and isotopic fractionation data suggest that denitrification was likely a predominant nitrogen reduction mechanism. In addition to nitrogen treatment, the IBR provided other benefits by improving erosion control, streambank stabilization, and increased bank-full storage from 6 m3 to 19.2 m3. Results indicated that the IBR improved water quality and other residential sub-watersheds with septic systems would benefit from similar practices.

show abstract

Section: Study Limitationsmentioning

confidence: 90%